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Cancer-associated fibroblasts (CAFs) can interact with macrophages in the tumor microenvironment by secreting extracellular vesicles (EVs), thereby affecting tumor progression. However, the mechanisms of CAF-secreted EVs in gastric cancer (GC) remain not well understood. Here, we investigated the effect of CAF-EVs on macrophage polarization in GC and the underlying mechanisms. Macrophage polarization was evaluated using flow cytometry and quantitative real-time polymerase chain reaction. GC cell proliferation was determined using cell counting kit-8, EdU, and colony formation assays. The molecular mechanism was explored using microarray analysis, dual-luciferase reporter assay, and RNA pull-down analysis. The results showed that CAFs secreted EVs that inhibit macrophage M1 polarization and promote M2 polarization. Moreover, miR-4253 expression was increased in CAF-EVs, and inhibition of miR-4253 reversed the macrophage polarization induced by EVs. IL6R was identified as the target of miR-4253. Additionally, macrophages treated with EVs that encapsulated miR-4253 promote GC cell proliferation. In conclusion, CAF-secreted EVs packaging miR-4253 facilitate macrophage polarization from M1 to M2 phenotype by targeting IL6R, thereby accelerating GC cell proliferation. The findings suggest that EV-encapsulated miR-4253 may be a promising therapeutic target of GC.

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.

Anomaly detection is a crucial research field in computer vision with diverse applications in practical scenarios. The common anomaly detection methods employed currently consist of autoencoders, generative adversarial networks, and knowledge distillation (KD) models. However, the teacher and student models in KD might not always yield distinct representations to signify anomalies due to their similar model structure and data flow. This study proposes a novel autoencoder-like KD model based on the attention mechanism for anomaly detection. The pre-trained teacher model incorporates a dual attention module as the encoder, while the student model integrates the same dual attention module as the decoder. The teacher guides the student to learn the feature knowledge of the input image. To connect the teacher-student model, a BottleNeck module is employed, converting the features extracted from the teacher model into more compact latent codes for precise restoration by the student model, thereby achieving anomaly detection. In general, the proposed model exhibits superior performance compared to other existing anomaly detection models on specific datasets. Experimental results demonstrate that the proposed model attains the state-of-the-art (SOTA) performance in anomaly detection on the public dataset MVTec. It achieves an average AUC of 98.2% and 98.0% at sample and pixel levels, respectively.

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.

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.

Abstract Background Alzheimer’s disease (AD), an age-related neurodegenerative disorder and a serious public health concern, is mainly caused by β-amyloid (Aβ)-induced toxicity. Currently, a limited number of drugs are effective against AD, and only a few are used for its treatment. According to traditional Chinese medicine, white wax is mainly composed of policosanol, hexacosanol, and octacosanol. Policosanol has been shown to reduce lipid levels in blood and alleviate the symptoms associated with diabetic complications and neurodegenerative disorders, such as Parkinson’s disease and AD. However, the efficacy of policosanol depends on the purity and composition of the preparation, and the therapeutic efficacy of policosanol derived from insect wax (PIW) in AD is unknown. Methods Here, we identified the main components of PIW and investigated the effects of PIW on Aβ-induced toxicity and life-span in a transgenic Caenorhabditis elegans model of AD, CL4176. Furthermore, we estimated the expression of amyloid precursor-like protein (apl-1) and the genes involved in various pathways associated with longevity and alleviation of AD-related symptoms in PIW-fed CL4176. Results PIW mainly consists of tetracosanol, hexacosanol, octacosanol, and triacontanol; it could decrease the Aβ-induced paralysis rate from 86.87 to 66.97% (P

As a temporary means of water transportation, floating bridges play an important role in the military and other fields. However, traditional floating bridges have limitations such as large size, heavy weight, and slow construction time. In this paper, we propose a rigid-flexible composite folding floating bridge. The main structure of the floating bridge consists of three layers: the bridge deck, airbag, and water bag. The floating bridge units are connected by flexible connectors to allow for pre-connection and folding of the bridge, reducing storage and transportation space, and improving construction efficiency. The proposed floating bridge also has a complete engineering application design and has been checked for safety and reliability (including the strength, buoyancy, and bearing capacity of the connections). We used AQWA software to simulate and analyze the anchorage scheme of the floating bridge and its response to wave loads and conducted a ballast test on a floating bridge model to verify its feasibility as a main bearing body. The results show that the floating bridge we designed has the advantages of being lightweight, having fewer consumables, having a small storage and transportation space, and being able to be constructed quickly.

ABSTRACT Hypoxia signaling is a key regulator in the development and progression of many types of human malignancies, including viral cancers. The latency-associated nuclear antigen (LANA), encoded by Kaposi’s sarcoma-associated herpesvirus (KSHV) during latency, is a multifunctional protein that plays an essential role in viral episome maintenance and lytic gene silencing for inducing tumorigenesis. Although our previous studies have shown that LANA contains a SUMO-interacting motif (LANASIM), and hypoxia reduces SUMOylated KAP1 association with LANASIM, the physiological proteomic network of LANASIM-associated cellular proteins in response to hypoxia is still unclear. In this study, we individually established cell lines stably expressing wild-type LANA (LANAWT) and its SIM-deleted mutant (LANAdSIM) and treated them with or without hypoxia, followed by coimmunoprecipitation and mass spectrometry analysis to systemically identify the hypoxia-responsive profile of LANASIM-associated cellular proteins. We found that in hypoxia, the number of cellular proteins associated with LANAWT instead of LANAdSIM was dramatically increased. Functional network analysis revealed that two major pathways, which included cytoskeleton organization and DNA/RNA binding and processing pathways, were significantly enriched for 28 LANASIM-associated proteins in response to hypoxia. HNRNPU was one of the proteins consistently identified that interacted with LANASIM in different proteomic screening systems and responded to hypoxia. This study provides a proteomic profile of LANASIM-associated proteins in hypoxia and facilitates our understanding of the role of the collaboration between viral infection and the hypoxia response in inducing viral persistence and tumorigenesis. IMPORTANCE Kaposi’s sarcoma-associated herpesvirus (KSHV) has been reported to be involved in the regulation of host proteins in response to hypoxic stress. LANA, one of the key latent proteins, contains a SUMO-interacting motif (LANASIM) and reduces the association with SUMOylated KAP1 upon hypoxic treatment. However, the physiological systematic network of LANASIM-associated cellular proteins in hypoxia is still unclear. Here, we revealed two major pathways, which included cytoskeleton organization and DNA/RNA binding and processing pathways, that were significantly enriched for 28 LANASIM-associated proteins in hypoxia. This discovery not only provides a proteomic profile of LANASIM-associated proteins in hypoxia but also facilitates our understanding of the collaboration between viral infection and hypoxic stress in inducing viral persistence and tumorigenesis.

Policosanol (PC) is a mixture of long-chain fatty alcohols that exhibits multiple biological activities, such as reducing blood lipid and cholesterol levels, lowering blood pressure, and extenuating liver inflammation. To assess PC’s impact on cognitive behavior and function, PC was prepared from Ericerus pela wax using a reduction method and analyzed using gas chromatography (GC). A total of 60 mice were randomly divided into six groups of 10 animals each: control (0.5% CMC-Na solution, i.g.), model (0.5% CMC-Na solution, i.g.), donepezil (3 mg/kg, i.g.), PC low- (2 g/kg, i.g.), medium (4 g/kg, i.g.), and high- (6 g/kg, i.g.) dose groups. All the groups were administered daily for 28 consecutive days. There were four parameters—escape latency, crossings of platform, swimming distance, and time spent in the target quadrant—that were recorded to evaluate the cognitive performance of mice in the Morris Water Maze (MWM). After MWM testing, the levels of acetylcholine (ACh), acetylcholinesterase (AChE), superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH) that were present in brain tissue were determined using assay kits. The GC data showed that PC consisted of four major components: tetracosanol (14.40%), hexacosanol (48.97%), octacosanol (25.40%), and triacontanol (4.80%). In the MWM test, PC significantly decreased the escape latency (p < 0.05) and increased the crossings of the platform (p < 0.05) and swimming distance (p < 0.05) and time in the target quadrant (p < 0.05) in rodents compared to that in the model group. Moreover, PC increased the levels of ACh, SOD, and GSH; inhibited AChE; and reduced MDA in the brain tissue of the tested animals. This is the first report to evaluate the efficacy of PC for cognitive behavior and function in animals. Our findings demonstrate that PC from E. pela wax is likely to exert an enhancing effect on learning and memory by promoting the cholinergic system and attenuating oxidative stress, which will provide a new insight into the efficacy of PC and expand its application in the food, nutraceutical, and beverage industries.

Sirtuin 1 (Sirt1) is a NAD+ dependent lysine deacetylase associated with the pathogenesis of various diseases including cancer. In many cancer types Sirt1 expression is increased and higher levels have been associated with metastasis and poor prognosis. However, it was also shown, that Sirt1 can have tumor suppressing properties and in some instances even a dual role for the same cancer type has been reported. Increased Sirt1 activity has been linked to extension of the life span of cells, respectively, organisms by promoting DNA repair processes and downregulation of tumor suppressor proteins. This may have the downside of enhancing tumor growth and metastasis. In mice embryonic fibroblasts depletion of Sirt1 was shown to decrease levels of the DNA damage sensor histone H2AX. Impairment of DNA repair mechanisms by Sirt1 can promote tumorigenesis but also lower chemoresistance toward DNA targeting therapies. Despite many biological studies, there is currently just one small molecule Sirt1 inhibitor in clinical trials. Selisistat (EX-527) reached phase III clinical trials for treatment of Huntington's Disease. New small molecule Sirt1 modulators are crucial for further investigation of the contradicting roles of Sirt1 in cancer. We tested a small library of commercially available compounds that were proposed by virtual screening and docking studies against Sirt1, 2 and 3. A thienopyrimidone featuring a phenyl thiocyanate moiety was found to selectively inhibit Sirt1 with an IC50 of 13 μM. Structural analogs lacking the thiocyanate function did not show inhibition of Sirt1 revealing this group as key for the selectivity and affinity toward Sirt1. Further analogs with higher solubility were identified through iterative docking studies and in vitro testing. The most active compounds (down to 5 μM IC50) were further studied in cells. The ratio of phosphorylated γH2AX to unmodified H2AX is lower when Sirt1 is depleted or inhibited. Our new Sirtuin 1 inhibiting thiocyanates (S1th) lead to similarly lowered γH2AX/H2AX ratios in mouse embryonic fibroblasts as Sirt1 knockout and treatment with the reference inhibitor EX-527. In addition to that we were able to show antiproliferative activity, inhibition of migration and colony forming as well as hyperacetylation of Sirt1 targets p53 and H3 by the S1th in cervical cancer cells (HeLa). These results reveal thiocyanates as a promising new class of selective Sirt1 inhibitors.

Latent Epstein-Barr virus (EBV) infection is strongly associated with several malignancies, including B-cell lymphomas and epithelial tumors. EBNA1 is a key antigen expressed in all EBV-associated tumors during latency that is required for maintenance of the EBV episome DNA and the regulation of viral gene transcription. However, the mechanism utilized by EBV to maintain latent infection at the levels of posttranslational regulation remains largely unclear. Here, we report that EBNA1 contains two SUMO-interacting motifs (SIM2 and SIM3), and mutation of SIM2, but not SIM3, dramatically disrupts the EBNA1 dimerization, while SIM3 contributes to the polySUMO2 modification of EBNA1 at lysine 477 in vitro. Proteomic and immunoprecipitation analyses further reveal that the SIM3 motif is required for the EBNA1-mediated inhibitory effects on SUMO2-modified STUB1, SUMO2-mediated degradation of USP7, and SUMO1-modified KAP1. Deletion of the EBNASIM motif leads to functional loss of both EBNA1-mediated viral episome maintenance and lytic gene silencing. Importantly, hypoxic stress induces the SUMO2 modification of EBNA1, and in turn the dissociation of EBNA1 with STUB1, KAP1 and USP7 to increase the SUMO1 modification of both STUB1 and KAP1 for reactivation of lytic replication. Therefore, the EBNA1SIM motif plays an essential role in EBV latency and is a potential therapeutic target against EBV-associated cancers.

This study aimed to investigate the effect of processing methods on inhibiting lipid oxidation of deep fried crickets (Gryllus bimaculatus) during storage. Four antioxidants and two packaging methods were used. The effects of different antioxidants and packaging methods on composition of fatty acids, contents of free fatty acids (FFA), peroxide value (PV), and thiobarbituric acid reactive substances (TBARSs) value of deep fried Gryllus bimaculatus were analyzed during 150 days of storage. The composition of fatty acids changed and the content of FFA, PV, and TBARs value also increased with the extension of storage time, indicating that the lipid oxidation dominated by oxidation of unsaturated fatty acids could occur in deep fried Gryllus bimaculatus during storage. In the same storage period, the total content of FFA, PV, and TBARs value of samples treated with antioxidants and vacuum-filling nitrogen packaging were lower than those of controls, suggesting that antioxidants and vacuum-filling nitrogen packaging have noticeable effects on inhibiting lipid oxidation and improving the quality of deep fried crickets, and dibutyl hydroxyl toluene (BHT) was found as the most effective antioxidant in this study. The results may provide a reliable reference for processing of deep fried edible insects.

Proteasomes are critical proteases in the cell responsible for the turnover of many cytoplasmic and nuclear proteins. They are essential for many cellular processes and various diseases are associated with their malfunctioning. Proteasome activity depends on the nature of the catalytic subunits, as well as the interaction with associated proteasome regulators. Here we describe various fluorescence-based methods to study proteasome function, highlighting the use of activity-based probes to study proteasome localization, dynamics, and activity in living cells.

Ship hatch corner is a common structure in a ship and its fatigue problem has always been one of the focuses in ship engineering due to the long–term high–stress concentration state during the ship’s life. For investigating the fatigue life improvement of the ship hatch corner under different shot peening (SP) treatments, a series of fatigue tests, residual stress and surface topography measurements were conducted for SP specimens. Furthermore, the distributions of the surface residual stress are measured with varying numbers of cyclic loads, investigating the residual stress relaxation during cyclic loading. The results show that no matter which SP process parameters are used, the fatigue lives of the shot–peened ship hatch corner specimens are longer than those at unpeened specimens. The relaxation rate of the residual stress mainly depends on the maximum compressive residual stress (σRSmax) and the depth of the maximum compressive residual stress (δmax). The larger the values of σRSmax and δmax, the slower the relaxation rates of the residual stress field. The results imply that the effect of residual stress field and surface roughness should be considered comprehensively to improve the fatigue life of the ship hatch corner with SP treatment. The increase in peening intensity (PI) within a certain range can increase the depth of the compressive residual stress field (CRSF), so the fatigue performance of the ship hatch corner is improved. Once the PI exceeds a certain value, the surface damage caused by the increase in surface roughness will not be offset by the CRSF and the fatigue life cannot be improved optimally. This research provides an approach of fatigue performance enhancement for ship hatch corners in engineering application.

In order to investigate the effect of shot distance and impact sequence on the residual stress distribution of 42CrMo steel in shot peening (SP) finite element (FE) simulation, 3D dynamic models with order dimple pattern and stochastic dimple pattern were established via ABAQUS/Explicit 6.14, and the simulation results were compared with experiments. The results show that shot overlap has a significant effect on the residual stress distribution of peened parts. Meanwhile, there is a threshold (related to SP parameter) for shot distance in the vertical and horizontal directions. When the shot distance is greater than the threshold in this direction, the residual stress distribution after SP tends to be stable. The impact sequence has almost no effect on the impact of a small number of shots, but this effect will appear when the number of shots increases. It is necessary to avoid shot overlap and continuous impact of adjacent dimples when the FE model is established; on this basis, the distance between shots and the number of layers of the shots can be reduced as much as possible without affecting the residual stress distribution. In addition, the comparison of simulation and experimental results shows that the residual stress evaluation area consistent with the experimental measurement is essential to obtain accurate residual stress distribution in the FE simulation process.

In order to investigate the non-linear fatigue cumulative damage of joints in ocean structural parts, one type of low carbon steel Q345D was employed to prepare designed T-type specimens, and a series of fatigue experiments were carried out on the specimens under two-step repeating variable amplitude loading condition. The chosen high cyclic loads were larger than the constant amplitude fatigue limit (CAFL) and the chosen low cyclic loads were below the CAFL. Firstly, the S-N curve of designed T-type specimen was obtained via different constant amplitude fatigue tests. Then, a series of two-step repeating variable load were carried out on designed T-type specimens with the aim of calculating the cumulative damage of specimen under the variable fatigue load. The discussions about non-linear fatigue cumulative damage of designed T-type specimens and the interaction effect between the high and low amplitude loadings on the fatigue life were carried out, and some meaningful conclusions were obtained according to the series of fatigue tests. The results show that fatigue cumulative damage of designed T-type specimens calculated based on Miner’s rule ranges from 0.513 to 1.756. Under the same cycle ratio, the cumulative damage increases with the increase of high cyclic stress, and at the same stress ratio, the cumulative damage increases linearly with the increase of cycle ratio. Based on the non-linear damage evaluation method, it is found that the load interaction effect between high and low stress loads exhibits different damage or strengthening effects with the change of stress ratio and cycle ratio.

The antioxidant capacity of maca has been considered to be the basis for other bioactivities, and revealing the active antioxidant compounds would help to elucidate a variety of bioactive compounds. In this study, the correlation between the antioxidant activity of maca and secondary metabolites, including ferric reducing antioxidant potential (FRAP), hydroxyl radical scavenging ability (HRSA), lipid peroxidation inhibition ability (LPIA), total phenolic contents (TPCs), total alkaloid contents (TACs), and total sterol contents (TSCs), was investigated by measuring. Chloroform was selected to be an efficient extraction solvent for antioxidant compounds in maca by polarity fractions test. The results showed that TPC exhibited significant linear correlations (P