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Impact resistance analysis and multi-objective optimization of polyurea-coated auxetic honeycomb sandwich panels

MATERIALS TODAY COMMUNICATIONS 2023年 35卷

作者： He, Qiang Li, Lizheng Jing, xuwen jiang, Yonggang Yan, Dejun Jiangsu Univ Sci & Technol Sch Mech Engn Zhenjiang 212000 Peoples R China Cssc Huangpu Wenchong Shipbuilding Co Ltd Guangzhou 510715 Peoples R China

To investigate the protective capacity and mechanism of polyurea-coated auxetic honeycomb sandwich structures under impact loading. The mechanical properties of a sandwich panel under the action of a cylindrical punch is numerically simulated by LS-DYNA. Firstly, the impact of different coating positions on the protective properties of sandwich panels is analyzed and concluded which coating method is most effective. Then, the mechanism of the impact resistance of sandwich panels strengthened by the thickness, grading and orientation of the auxetic honeycomb cores is discussed by outline volume analysis. Finally, a multi-objective optimization of the sandwich panel's internal concave hexagonal structural parameters with the best impact resistance is carried out. It is shown that the coating of polyurea elastomers can effectively increase the impact protection performance of sandwich panels. The best impact resistance is achieved by the back side coated sandwich panel (type B). Increasing the wall thickness of auxetic honeycomb and the thickness of the upper graded honeycomb core can effectively increase the impact resistance of the type B sandwich panel. Optimized type B sandwich panel has a 6.2% reduction in maximum deflection (D) compared to the unoptimized version. The findings of this research provide a reference for the study and design of polyurea-coated sandwich panels.

关键词： Polyurea elastomer Auxetic honeycomb Impact resistance Numerical simulation

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Numerical and experimental investigation of the residual stress distribution of internal thread cold extrusion and tap wear

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STRAIN 2024年第1期60卷 e12459-e12459页

作者： Wan, Nian He, Qiang Jing, xuwen jiang, Yonggang Zhou, Honggen Jiangsu Univ Sci & Technol Sch Mech Engn Zhenjiang Peoples R China Cssc Huangpu Wenchong Ship Bldg Co Ltd Guangzhou Peoples R China Jiangsu Univ Sci & Technol Sch Mech Engn Zhenjiang 212000 Peoples R China

In order to improve the thread-forming quality of diesel engine piston connecting rod, the internal thread cold extrusion process was adopted for the through-hole structure of 42CrMo4 high-strength steel. The influence of different structural parameters of the tap on the residual stress distribution of the cold extrusion internal threads and self-wear were discussed with the help of three-dimensional elastic-plastic finite element model. The wear of tap was observed by an electron microscope, coordinated with the residual stress distribution of thread was measured by X-ray diffraction to explore the relationship between residual stress distribution of the cold extrusion internal thread, tool wear and tap structure. The optimal combination of tap structure parameters of residual stress and tool wear was obtained through grey relation method. The residual compressive stress and the depth of stress layer near the thread surface increased and the wear condition of the extrusion tap was improved when the tap with optimised structural parameters was used for processing, while maintaining the original thread connection strength. The results show that the internal thread with better-forming quality can be obtained by using the optimised extrusion tap, while the service life of the tap was prolonged.

关键词： cold extrusion internal thread high-strength steel residual stress structural parameter tool wear

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Surveillance of norovirus contamination in commercial fresh/frozen berries from Heilongjiang Province, China, using a TaqMan real-time RT-PCR assay

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FOOD MICROBIOLOGY 2019年 82卷 119-126页

作者： Gao, xuwen Wang, Ziwei Wang, Yixin Liu, Zhongmei Guan, Xueting Ma, Yingying Zhou, Han jiang, Yanping Cui, Wen Wang, Li Xu, Yigang Northeast Agr Univ Coll Vet Med Changjiang Rd 600 Harbin Heilongjiang Peoples R China Heilongjiang Key Lab Anim Dis Control & Pharmaceu Harbin Heilongjiang Peoples R China Heilongjiang Entry Exit Inspect & Quarantine Bur Technol Ctr Harbin Heilongjiang Peoples R China Northeast Agr Univ Coll Anim Sci & Technol Harbin Heilongjiang Peoples R China

Norovirus (NoV), a major food-borne virus, causes non-bacterial acute gastroenteritis in humans. Berries are generally harvested from low-growing bushes by hand and are minimally processed before being sold to consumers. Therefore, the consumption of berries has been linked to numerous food-borne gastroenteritis outbreaks caused by NoV in many countries. We performed a survey of NoV contamination in commercial fresh/frozen berry fruits collected from 2016 to 2017 in the Heilongjiang Province, the main berry-producing area in China, using a TaqMan-based real-time reverse transcription-PCR assay. Among 900 frozen and 900 fresh domestic retail berry samples, the prevalence of NoV was 9% (81/900) and 12.11% (109/900), including 35.80% (29/81) and 29.36% (32/109) of genotype GI alone, 54.32% (44/81) and 60.55% (66/109) of GII alone, and 9.88% (8/81) and 10.09% (11/109) of both GI and GII, respectively. No NoV was detected among the 677 frozen berry samples for export. Thus, the occurrence of NoV contamination was significantly higher in domestic berries than in exported berries and higher in fresh berries than in frozen berries. This study highlights the need for further risk surveillance for NoV contamination in berries produced in the Heilongjiang Province and recommends region-extended monitoring of retail berries for NoV.

关键词： Norovirus Berries Real-time RT-PCR Risk surveillances

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Gestational diabetes mellitus prediction model: A risk factors analysis of pregnant women with gestational diabetes mellitus but have normal oral glucose tolerance test results in the second trimester of pregnancy

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TECHNOLOGY AND HEALTH CARE 2021年第1_suppl期29卷 S57-S63页

作者： Lu, Jiayu Zhang, Song jiang, Hongqing Yang, Lin Hao, Dongmei Yang, Yimin Li, xuwen Chen, Aiqing Shao, Jing Liu, Xiaohong Beijing Univ Technol Fac Environm & Life Sci Beijing Int Base Sci & Technol Cooperat Intelligent Physiol Measurement & Clin Translat Beijing 100124 Peoples R China Haidian Maternal & Children Hlth Hosp Beijing 100080 Peoples R China Beijing Yes Med Devices Co Ltd Beijing 100152 Peoples R China

BACKGROUND: Oral glucose tolerance test (OGTT) is a standard for the diagnosis of gestational diabetes mellitus (GDM). However, clinically, some cases with normal results were diagnosed as GDM in the third trimester. OBJECTIVE: To establish a risk model based on energy metabolism, epidemiology, and biochemistry that could predict the GDM pregnant women with normal OGTT results in the second trimester. METHODS: Qualitative and quantitative data were analyzed to find out the risk factors, and the binary logistic backward LR regression was used to establish the prediction model of each factor and comprehensive factor, respectively. RESULTS: The risk factors including the rest energy expenditure per kilogram of body weight, oxygen consumption per kilogram of body weight, if more than the weight gain criteria of the Institute of Medicine, the increase of body mass index between the second trimester and pre-pregnancy, and fasting blood glucose. By comparison, the comprehensive model had the best prediction performance, indicating that 85% of high-risk individuals were correctly classified. CONCLUSION: Energy metabolism, epidemiology, and biochemistry had better recognition ability for the GDM pregnant women with normal OGTT results in the second trimester. The addition of metabolic factors in the second trimester also improved the overall prediction performance.

关键词： Prediction model gestational diabetes mellitus rest energy metabolism

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The relationship between geometry and hemodynamics of the stenotic carotid artery based on computational fluid dynamics

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CLINICAL NEUROLOGY AND NEUROSURGERY 2023年第1期231卷 107860-107860页

作者： Liu, Yongsheng jiang, Guinan Wang, xuwen An, Xiangbo Wang, Feng Dalian Med Univ Dept Pathol Affiliated Hosp 1 Dalian Peoples R China 222 Zhongshan Rd Dalian Peoples R China

Objective: The purpose of this work was to investigate the relationship between the geometric factors and the hemodynamics of the stenotic carotid ***: We retrospectively reviewed data of patients with carotid stenosis (40%-95%). The Navier-Stokes equations were solved using ANSYS CFX 18.0. Correlation analysis was based on Spearman's test. Geometric variables (p < 0.1 in the univariate analysis) were entered into the logistical regression. A receiver-operating characteristics analysis was used to detect hemodynamically significant lesions. Results: 81 patients (96 arteries) were evaluated. The logistic regression analysis revealed that the translesional pressure ratio was significantly correlated with the stenosis degree (OR = 1.147, p < 0.001) and the angle between internal carotid artery and external carotid artery (angle ?) (OR = 0.933, p = 0.01). The translesional wall shear stress ratio was significantly correlated with stenosis degree (OR = 1.094, p < 0.001), lesion length (OR = 0.873, p = 0.01), lumen area of internal carotid artery (OR = 0.867, p = 0.002), and lumen area of common carotid artery (OR = 1.058, p = 0.01). For predicting low translesional pressure ratio, the AUC was 0.71 (p < 0.001) for angle ?, and was 0.87 (p < 0.001) for stenosis degree. For predicting high translesional wall shear stress ratio, the AUC was 0.62 (p = 0.04) for lumen area of internal carotid artery, and was 0.77 (p < 0.001) for stenosis ***: Apart from stenosis degree, other geometric characteristics of lesions may also have an influence on hemodynamics of the stenotic carotid artery.

关键词： Carotid artery Computational fluid dynamics Geometry Hemodynamics Stenosis

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Nanomaterials with dual immunomodulatory functions for synergistic therapy of breast cancer brain metastases

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Bioactive Materials 2023年第9期27卷 474-487页

作者： Zhenhao Zhao Chufeng Li Yiwen Zhang Chao Li Yongchao Chu xuwen Li Peixin Liu Hongyi Chen Yu Wang Boyu Su Qinjun Chen Tao Sun Chen jiang Department of Pharmaceutics School of PharmacyFudan UniversityKey Laboratory of Smart Drug DeliveryMinistry of EducationState Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceShanghai201203China

A long-standing paucity of effective therapies results in the poor outcomes of triple-negative breast cancer brain *** has made progress in the treatment of tumors,but limited by the non-immunogenicity of tumors and strong immunosuppressive environment,patients with TNBC brain metastases have not yet benefited from *** immunoregulatory strategies with enhanced immune activation and reversal of the immunosuppressive microenvironment provide new therapeutic options for ***,we propose a cocktail-like therapeutic strategy of microenvironment regulation-chemotherapy-immune synergistic sensitization and construct reduction-sensitive immune microenvironment regulation nanomaterials(SIL@T).SIL@T modified with targeting peptide penetrates the BBB and is subsequently internalized into metastatic breast cancer cells,releasing silybin and oxaliplatin responsively in the ***@T preferentially accumulates at the metastatic site and can significantly prolong the survival period of model *** studies have shown that SIL@T can effectively induce immunogenic cell death of metastatic cells,activate immune responses and increase infiltration of CD8+T ***,the activation of STAT3 in the metastatic foci is attenuated and the immunosuppressive microenvironment is *** study demonstrates that SIL@T with dual immunomodulatory functions provides a promising immune synergistic therapy strategy for breast cancer brain metastases.

关键词： Breast cancer brain metastases Drug delivery Immunogenic cell death Microenvironmental regulation STAT3

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Anomaly Detection for Multivariate Time Series Based on Contrastive Learning and Autoformer

Anomaly Detection for Multivariate Time Series Based on Cont...

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International Conference on Computer Supported Cooperative Work in Design

作者： xuwen Shang Jue Zhang Xingguo jiang Hong Luo Beijing Key Laboratory of Intelligent Telecommunication Software and Multimedia Beijing University of Posts and Telecommunications Beijing China Department of Computer Science and Engineering Beihang University Beijing China

ISBN: (数字)9798350349184

ISBN: (纸本)9798350349191

Nowadays, due to the increasingly complex and huge data flow, anomaly detection has become an important technology to ensure the high security and reliability of the systems. It helps identify unusual observations in the data, thereby protecting safety and reducing risk. However, in the field of multivariate temporal anomaly detection, there are still some difficulties in spatio-temporal correlation mining of variables, generalization ability in dealing with complex temporal sequences, and feature learning under different granularity. Therefore, we propose an unsupervised anomaly detection method for multivariate time series based on contrastive learning and Autoformer autoencoder. In order to fully explore the spatio-temporal correlation of time series data, this paper uses Graph Attention Network and Auto-Correlation to jointly learn spatio-temporal correlation, and obtain positive and negative pairs through time-domain and frequency-domain data augmentation. Finally, the Autoformer autoencoder is used for anomaly detection in a predictive manner. In the loss function section, a joint loss function is formed by introducing contrastive learning losses at the time step and time window granularity, combined with prediction loss, to improve the learning effect. This paper investigates the performance of the proposed method through experiments on the SMAP and MSL public datasets, and achieves better results than baseline methods.

关键词： Correlation Computational modeling Time series analysis Contrastive learning Computer architecture Stability analysis Safety

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Experimental Study on Noncoaxial Characteristics of Saturated Remolded Loess

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ADVANCES IN CIVIL ENGINEERING 2020年第1期2020卷

作者： jiang, Xuemeng Niu, Haoshuang Huang, Wenpeng Shang, xuwen Wang, Deng Changan Univ Key Lab Special Area Highway Engn Minist Educ Xian 710064 Peoples R China

In practical engineering, if the influence of noncoaxial stress and strain is not considered, part of soil deformation will be ignored, resulting in the structural design which is not safe enough. A series of undrained tests was performed on remolded loess specimens using a hollow cylinder apparatus to examine the coupling between principal stress magnitude and direction in these specimens. First, the elastic parameters of remolded loess were obtained, and these parameters were used as the basis for investigating the noncoaxiality of the soil body under principal stress axis rotation (PSAR). The effects of elastic strain, intermediate principal stress coefficient, and magnitude of the deviatoric stress on the noncoaxiality of remolded loess were also investigated. The results of these experiments show that remolded loess exhibits significant noncoaxial behavior during PSAR. The noncoaxiality angle of remolded loess cyclically fluctuates with increases in the principal stress angle. It was also observed that the noncoaxiality angle will be overestimated if the effects of elastic strain are overlooked. Reversals in the direction of PSAR cause dramatic changes in the noncoaxiality angle. Increases in the intermediate principal stress coefficient are accompanied by increases in the noncoaxiality angle, up to a certain degree;however, these changes do not affect the development of the noncoaxiality angle. In coupled rotational tests with a range of deviatoric stress amplitudes, it was observed that changes in the deviatoric stress amplitude will affect the development of the noncoaxiality angle;increases in the deviatoric stress amplitude cause the noncoaxiality angle versus principle stress angle plot to shift to the left gradually, thus accelerating the trends of the noncoaxiality angle. Increases in the cycle number also increase the noncoaxiality of remolded loess.

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Oral immunization of mice with a probiotic Lactobacillus casei constitutively expressing the α-toxoid induces protective immunity against Clostridium perfringens α-toxin

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VIRULENCE 2019年第1期10卷 166-179页

作者： Gao, xuwen Ma, Yingying Wang, Zhuo Bai, Jing Jia, Shuo Feng, Baohua jiang, Yanping Cui, Wen Tang, Lijie Li, Yijing Wang, Li Xu, Yigang Northeast Agr Univ Coll Vet Med Harbin Heilongjiang Peoples R China China Minist Agr Key Lab Anim Pathogen Biol Northeastern Sci Inspect Stn Harbin Heilongjiang Peoples R China Northeast Agr Univ Heilongjiang Key Lab Anim Dis Control & Pharmaceu Harbin Heilongjiang Peoples R China

Clostridium perfringens alpha-toxin is one of the major virulence factors during C. perfringens infection, causing hemolysis of erythrocytes in various species. Here, genetically engineered Lactobacillus casei (pPG-alpha/L. casei 393) constitutively expressing the toxoid of C. perfringens alpha-toxin was generated and its immunogenicity in mice for induction of protective immunity against the alpha-toxin was evaluated via oral immunization. The alpha-toxoid was constitutively expressed by pPG-alpha/L. casei 393 without a specific inducer, as confirmed by western blotting, laser confocal microscopy, and flow cytometry. In an experiment on BALB/c mice to evaluate the oral immunogenicity of pPG-alpha/L. casei 393, significant levels of a specific secretory IgA (sIgA) antibody in the intestinal mucus and feces and an IgG antibody in the serum of the probiotic vaccine group were detected after booster immunization (p < 0.05) as compared with the pPG/L. casei 393 and PBS control groups. These antibodies effectively neutralized C. perfringens natural alpha-toxin. Moreover, significantly higher levels of cytokines IL-2, IL-4, IL-10, IL-12, IL-17, and interferon (IFN) gamma in the serum and increased proliferation of spleen lymphocytes obtained from mice orally immunized with pPG-alpha/L. casei 393 were detected. With a commercial C. perfringens type A inactivated vaccine as a control, immune protection provided by the probiotic vaccine against C. perfringens alpha-toxin was evaluated, and 90% and 80% protection rates were observed, respectively. Therefore, strain pPG-alpha/L. casei 393 effectively elicited mucosal, humoral, and cellular immunity, suggesting that pPG-alpha/L. casei 393 is a promising candidate for development of a vaccine against C. perfringens alpha-toxin.

关键词： Clostridium perfringens alpha-toxoid genetically engineered Lactobacillus casei oral immunization

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Folic acid-decorated vitamin E Poly(ethylene glycol) monoplatinum ester with disulfide bond as theranostic nanoparticle for drug resistant tumor diagnosis and treatment

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MATERIALS RESEARCH EXPRESS 2023年第11期10卷 115404-115404页

作者： Li, Zhuoran Yang, Huikang Xu, Fan Zeng, xuwen Huang, Haowei jiang, Xinqing Jinan Univ Dept Radiol Guangzhou Red Cross Hosp Guangzhou Guangdong Peoples R China South China Univ Technol Guangzhou Peoples Hosp 1 Sch Med Dept Radiol Guangzhou Guangdong Peoples R China Jinan Univ Dept Radiotherapy Guangzhou Red Cross Hosp Guangzhou Guangdong Peoples R China Jinan Univ Guangzhou Peoples Hosp 1 Dept Radiol Guangzhou Guangdong Peoples R China

Vitamin E Poly(ethylene glycol) monoplatinum ester (TPGS) nanoparticles have attracted much attention in recent years for overcome multidrug resistance. Herein, a well-defined folic acid (FA)-conjugated and disulfide bond-linked polymer (FA-SS-TPGS) was synthesized. These polymer nanoparticles were utilized as theranostic agents for tumor-targeted magnetic resonance imaging (MRI) and chemotherapy. By loading doxorubicin (DOX) and superparamagnetic iron oxide (SPIO) particles into TPGS nanoparticles, FA-SS-TPGS@DOX/SPIO nanoparticles are obtained. In vitro drug release studies revealed that under a reducing environment in the presence of glutathione (GSH), approximately 100% of the doxorubicin (DOX) was released from the disulfide bond-linked theranostic nanoparticles within 24 h. DOX and SPIO were efficiently delivered into HepG2-ADM cells due to the folate receptor-mediated endocytosis process of the nanoparticles. Additionally, the presence of glutathione (GSH) triggered the cleaving of the disulfide bonds, further facilitating the delivery of DOX and SPIO into the cells. Furthermore, the FA-SS-TPGS @DOX-SPIO nanoparticles exhibited strong MRI contrast enhancement properties. In conclusion, FA-SS-TPGS@DOX/SPIO are potential nanoparticles for tumor-targeted MRI and chemotherapy, which can also overcome multidrug resistance.

关键词： multidrug resistance TPGS tumor-targeted disulfide bond theranostic nanoparticles

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