Study on Thermodynamic Behavior, Microstructure and Mechanical Properties of Thin-Walled Parts by Selective Laser Melting

Biao Hu,Gaoshen Cai,Jinlian Deng,Kai Peng,Bingxu Wang 대한금속·재료학회 2024 METALS AND MATERIALS International Vol.30 No.1

To investigate the thermodynamic behavior of thin-walled parts fabricated by selective laser melting, an indirect sequentiallycoupled thermal–mechanical numerical modeling was developed. The three-dimensional Gaussian attenuation bodyheat source model and thermophysical parameters varying with temperature were considered. To validate the numericalmodel, the thin-walled part was manufactured by selective laser melting, and the experiment results were compared with thesimulation results. It is found that the variation trend of residual stress in simulation and experiment is in good agreement. Moreover, The microstructure and mechanical properties of the thin-walled parts were analyzed. The simulation resultsshow that the thermal conductivity and the heat accumulation have a critical influence on the evolution of the molten pooland cooling rate. The thermal stress along the laser scanning direction is larger than the other two directions, and the highstressarea is mainly distributed in the middle position of the part and the joint of the part and the substrate. Besides that, theX-component of stress of the top layer gradually decreases as the deposition layer increases. The experiment results showthat the microstructure of thin-walled parts is mainly composed of acicular martensite under the action of complex thermalcycle. The fracture mode of thin-walled parts show a typical quasi-brittle fracture.

The Study on Weibull Failure Models for Oil Gap–Paper Insulation Under Pulsating DC Voltage with Temperature

Jiang Tianyan,Deng Biao,He Qiaoqing,Bi Maoqiang,Chen Xi,Bao Lianwei,Zhou Xin 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.2

This paper presents Weibull failure models by experimental work and the step-up accelerated electrical–thermal test of oil-impregnated paper with 0.2 mm thickness is carried out under pulsating DC voltage at different temperatures. The breakdown voltage and failure time of the oil gap–paper insulation specimens at the same voltage duration is obtained by accelerated electrical–thermal aging test. The Weibull failure models of three-variable oil gap–paper insulation modified by Fallou and Ramu are established to analyze the failure data of oil gap–paper under different electric field intensities and temperatures. The statistical test method was used to evaluate the applicability and accuracy of two modified triple-variables Weibull failure models. The comprehensive test index of the Fallou-modified WFD is 1.6851, and the comprehensive test index of the Ramu-modified WFD is 1.8124. The Fallou-modified results were more accurate than Ramu-modified results in estimating the statistical distribution of failure data. Results show that the proposed triple-variable Weibull failure model could fully reflect the insulation state of oil gap–paper under the action of electric and thermal fields.

β-Catenin promotes long-term survival and angiogenesis of peripheral blood mesenchymal stem cells via the Oct4 signaling pathway

Wang Pengzhen,Deng Zhanyu,Li Aiguo,Li Rongsen,Huang Weiguang,Huang Weiguang,Chen Songsheng,Li Biao,Li Biao 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Stem cell therapy has been extensively studied to improve heart function following myocardial infarction; however, its therapeutic potency is limited by low rates of engraftment, survival, and differentiation. Here, we aimed to determine the roles of the β-catenin/Oct4 signaling axis in the regulation of long-term survival and angiogenesis of peripheral blood mesenchymal stem cells (PBMSCs). These cells were obtained from rat abdominal aortic blood. We showed that β-catenin promotes the self-renewal, antiapoptotic effects, and long-term survival of PBMSCs by activating the Oct4 pathway through upregulation of the expression of the antiapoptotic factors Bcl2 and survivin and the proangiogenic cytokine bFGF and suppression of the levels of the proapoptotic factors Bax and cleaved caspase-3. β-Catenin overexpression increased Oct4 expression. β-Catenin knockdown suppressed Oct4 expression in PBMSCs. However, β-catenin levels were not affected by Oct4 overexpression or knockdown. Chromatin immunoprecipitation assays proved that β-catenin directly regulates Oct4 transcription in PBMSCs. In vivo, PBMSCs overexpressing β-catenin showed high survival in infarcted hearts and resulted in better myocardial repair. Further functional analysis identified Oct4 as the direct upstream regulator of Ang1, bFGF, HGF, VEGF, Bcl2, and survivin, which cooperatively drive antiapoptosis and angiogenesis of engrafted PBMSCs. These findings revealed the regulation of β-catenin in PBMSCs by the Oct4-mediated antiapoptotic/proangiogenic signaling axis and provide a breakthrough point for improving the long-term survival and therapeutic effects of PBMSCs.

Genetic Analysis and Molecular Mapping of Gene Associated with Dominant Genic Male Sterility in Rapeseed (Brassica napus L.)

Jun Liu,Deng Feng Hong,Wei Lu,Ping Wu Liu,Qing Biao He,Guang Sheng Yang 한국유전학회 2008 Genes & Genomics Vol.30 No.6

Rs1046AB is a dominant genic male sterility (DGMS) line derived from a spontaneous mutant in Brassica napus. The sterility of this mutant was previously regarded as to be conditioned by the interaction of a dominant male sterility gene Ms and its non-allelic dominant restorer gene Mf (or Rf in previous reports). Recent genetic analyses, however, indicated that Ms and Mf may be allelic. In this research, we confirmed that a multiple allele model should be more appropriate to elucidate the heredity of DGMS line Rs1046AB. Based on this result, the present study emphasized on identifying DNA markers linked to Ms/Mf in an F2 population constructed by crossing Rs1046A with a double haploid (DH) restorer line (19514A). Twenty amplified fragment length polymorphism (AFLP) markers linked to the Ms/Mf locus were identified by combination of bulked segregant analysis (BSA) with AFLP technique. The target locus was detected to be co-segregating with the marker S05T05 and bracketed by two nearest markers, E14M01 and E01M02, with a genetic distance of 0.1 cM and 1.2 cM, respectively. Furthermore, we successfully converted two AFLP markers into sequence characterized amplified region (SCAR) markers. These findings provided direct molecular marker proofs on the inheritance model of this DGMS line, and the high density molecular markers linkage map around the Ms/Mf locus will be more informative for both marker-assisted selection (MAS) of elite male sterile lines and isolation of the Ms/Mf genes by positional cloning in future.

MicroRNA-206 Reduces Osteosarcoma Cell Malignancy In Vitro by Targeting the PAX3-MET Axis

Qian-Rong Deng,Fang-Biao Zhan,Xian-Wei Zhang,Shi-Long Feng,Jun Cheng,You Zhang,Bo Li,Li-Zhong Xie 연세대학교의과대학 2019 Yonsei medical journal Vol.60 No.2

Purpose: This study was undertaken to explore how miR-206 represses osteosarcoma (OS) development. Materials and Methods: Expression levels of miR-206, PAX3, and MET mRNA were explored in paired OS and adjacent tissuespecimens. A patient-derived OS cell line was established. miR-206 overexpression and knockdown were achieved by lentiviraltransduction. PAX3 and MET overexpression were achieved by plasmid transfection. Treatment with hepatocyte growth factor(HGF) was utilized to activate c-Met receptor. Associations between miR-206 and PAX3 or MET mRNA in OS cells were verifiedby AGO2-RNA immunoprecipitation assay and miRNA pulldown assay. OS cell malignancy was evaluated in vitro by cell proliferation,metastasis, and apoptosis assays. PAX3 and MET gene expression in OS cells was assayed by RT-qPCR and Western blot. Activation of PI3K-AKT and MAPK-ERK in OS cells were assayed by evaluating Akt1 Ser473 phosphorylation and total threoninephosphorylation of Erk1/2, respectively. Results: Expression levels of miR-206 were significantly decreased in OS tissue specimens, compared to adjacent counterparts,and were inversely correlated with expression of PAX3 and MET mRNA. miR-206 directly interacted with PAX3 and MET mRNAin OS cells. miR-206 overexpression significantly reduced PAX3 and MET gene expression in OS cells in vitro, resulting in significantdecreases in Akt1 and Erk1/2 activation, cell proliferation, and metastasis, as well as increases in cell apoptosis, while miR-206 knockdown showed the opposite effects. The effects of miR-206 overexpression on OS cells were reversed by PAX3 or METoverexpression, but only partially attenuated by HGF treatment. Conclusion: miR-206 reduces OS cell malignancy in vitro by targeting PAX3 and MET gene expression.

Introduction of Functionality, Selection of Topology, and Enhancement of Gas Adsorption in Multivariate Metal–Organic Framework-177

Zhang, Yue-Biao,Furukawa, Hiroyasu,Ko, Nakeun,Nie, Weixuan,Park, Hye Jeong,Okajima, Satoshi,Cordova, Kyle E.,Deng, Hexiang,Kim, Jaheon,Yaghi, Omar M. American Chemical Society 2015 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.137 No.7

<P>Metal-organic framework-177 (MOF-177) is one of the most porous materials whose structure is composed of octahedral Zn4O(-COO)(6) and triangular 1,3,5-benzenetribenzoate (BTB) units to make a three-dimensional extended network based on the qom topology. This topology violates a long-standing thesis where highly symmetric building units are expected to yield highly symmetric networks. In the case of octahedron and triangle combinations, MOFs based on pyrite (pyr) and rutile (rtl) nets were expected instead of qom. In this study, we have made 24 MOF-177 structures with different functional groups on the triangular BTB linker, having one or more functionalities. We find that the position of the functional groups on the BTB unit allows the selection for a specific net (qom, pyr, and rtl), and that mixing of functionalities (-H, -NH2, and -C4H4) is an important strategy for the incorporation of a specific functionality (-NO2) into MOF-177 where otherwise incorporation of such functionality would be difficult. Such mixing of functionalities to make multivariate MOF-177 structures leads to enhancement of hydrogen uptake by 25%.</P>

Oral administration of Schisandra chinensis extract suppresses Dnmt1 expression in Kunming mice ovaries

Wen-yong Li,Feng-Rui Wu,Deng-kun Li,Mi-mi Su,Yong Liu,Biao Ding,Rong Wang 한국유전학회 2016 Genes & Genomics Vol.38 No.12

The plant Schisandra chinensis contains a phytoestrogens, a type of naturally occurring estrogens which have multiple functions in a number of biological processes. To investigate the correlation between phytoestrogens and epigenetic modification, especially the effect of phytoestrogens on DNA methylation, sexually healthy female mice were used as an animal model in the present study. Briefly, the total RNA and protein were isolated from the ovary of mice after 7-day oral administration of Schisandra chinensis extract (SCE), while distilled water was given to the animals in the control group. Real-time PCR, Western blotting, and enzyme activity assays were performed to examine the effect of the extract of S. chinensis on Dnmt1 transcription and activity. A promoter assay was further conducted in MCF cells (ER positive) to explore also the influence of SCE on Dnmt1 transcriptional activity. The results revealed that the mRNA and protein expression levels of mouse Dnmt1 were both significantly downregulated in the treated group. The transcription of Dnmt1 was suppressed by SCE and in the E2-added group also. Meanwhile the numbers of oocytes at different stages were increased in the treated group when compared by histological analyses with those in the control group. Taken together, the results indicated that, similarly to the action of estrogen, phytoestrogens affected Dnmt1 transcription in mammals, regulating the related gene expression and cell differentiation. The findings of our examination provided also basic data and understanding for the correlation between phytoestrogens and epigenetic modification.

Dietary patterns and cardio-cerebrovascular disease in a Chinese population

Honglin Wang,Meng Qu,Peirong Yang,Biao Yang,Feng Deng 한국영양학회 2015 Nutrition Research and Practice Vol.9 No.3

BACKGROUND/OBJECTIVES: Dietary pattern and its association with cardio-cerebrovascular disease have not been studied in Baoji city by now. This study was aimed to identify the dietary patterns among Chinese adults in Baoji, and explore the association between these dietary patterns and cardio-cerebrovascular disease. SUBJECTS/METHODS: A total of 4,968 participants were included in this study at 12 counties. With multistage stratified random sampling and semi quantitative food frequency questionnaire, the prevalence of cardio-cerebrovascular disease and dietary intake were investigated in 2013. We used factor analysis to establish dietary patterns. RESULTS: A total of 4,968 participants over 15 years old were included in this study. Five dietary patterns were identified in Baoji: protein, balanced, beans, prudent, and traditional patterns. The protein dietary pattern mainly included animal and plant proteins and was negatively associated with hypertension as well as stroke. The balanced pattern included carbohydrates, protein, and fat and was negatively associated with hypertension as well as stroke. The beans pattern was mainly beans and beans products and was negatively associated with hypertension. The prudent pattern only included staple foods and pickled vegetables and was positively associated with hypertension as well as coronary heart disease. The traditional pattern was representative of local Baoji traditional recipes and was positively associated with hypertension. CONCLUSIONS: The protein, balanced, and beans dietary patterns showed many protective effects on cardio-cerebrovascular disease. Based on these results, Baoji city residents should be encouraged to choose protein, balanced, and beans dietary patterns and abandon prudent and traditional patterns to prevent incidence of hypertension, coronary heart disease, and stroke.

IRE1α protects against osteoarthritis by regulating progranulin-dependent XBP1 splicing and collagen homeostasis

Liang Li,Zhang Fengmei,Feng Naibo,Kuang Biao,Fan Mengtian,Chen Cheng,Pan Yiming,Zhou Pengfei,Geng Nana,Li Xingyue,Xian Menglin,Deng Lin,Li Xiaoli,Kuang Liang,Luo Fengtao,Tan Qiaoyan,Xie Yangli,Guo Fen 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

Osteoarthritis (OA) is a full-joint, multifactorial, degenerative and inflammatory disease that seriously affects the quality of life of patients due to its disabling and pain-causing properties. ER stress has been reported to be closely related to the progression of OA. The inositol-requiring enzyme 1α/X-box-binding protein-1 spliced (IRE1α/XBP1s) pathway, which is highly expressed in the chondrocytes of OA patients, promotes the degradation and refolding of abnormal proteins during ER stress and maintains the stability of the ER environment of chondrocytes, but its function and the underlying mechanisms of how it contributes to the progression of OA remain unclear. This study investigates the role of IRE1α/ERN1 in OA. Specific deficiency of ERN1 in chondrocytes spontaneously resulted in OA-like cartilage destruction and accelerated OA progression in a surgically induced arthritis model. Local delivery of AdERN1 relieved degradation of the cartilage matrix and prevented OA development in an ACLT-mediated model. Mechanistically, progranulin (PGRN), an intracellular chaperone, binds to IRE1α, promoting its phosphorylation and splicing of XBP1u to generate XBP1s. XBP1s protects articular cartilage through TNF-α/ERK1/2 signaling and further maintains collagen homeostasis by regulating type II collagen expression. The chondroprotective effect of IRE1α/ERN1 is dependent on PGRN and XBP1s splicing. ERN1 deficiency accelerated cartilage degeneration in OA by reducing PGRN expression and XBP1s splicing, subsequently decreasing collagen II expression and triggering collagen structural abnormalities and an imbalance in collagen homeostasis. This study provides new insights into OA pathogenesis and the UPR and suggests that IRE1α/ERN1 may serve as a potential target for the treatment of joint degenerative diseases, including OA.

Targeting treatment of bladder cancer using PTK7 aptamer-gemcitabine conjugate

Xiang Wei,Peng Yongbo,Zeng Hongliang,Yu Chunping,Zhang Qun,Liu Biao,Liu Jiahao,Hu Xing,Wei Wensu,Deng Minhua,Wang Ning,Liu Xuewen,Xie Jianfei,Hou Weibin,Tang Jin,Long Zhi,Wang Long,Liu Jianye 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Gemcitabine (GEM) is one of the first-line chemotherapies for bladder cancer (BC), but the GEMs cannot recognize cancer cells and have a low long-term response rate and high recurrence rate with side effects during the treatment of BC. Targeted transport of GEMs to mediate cytotoxicity to tumor and avoid the systemic side effects remains a challenge in the treatment of BC.Based on a firstly confirmed biomarker in BC-protein tyrosine kinase 7 (PTK7), which is overexpressed on the cell membrane surface in BC cells, a novel targeting system protein tyrosine kinase 7 aptamer-Gemcitabine conjugate (PTK7-GEMs) was designed and synthesized using a specific PTK7 aptamer and GEM through auto-synthesis method to deliver GEM against BC. In addition, the antitumor effects and safety evaluation of PTK7-GEMs was assessed with a series of in vitro and in vivo assays.PTK7-GEMs can specifically bind and enter to BC cells dependent on the expression levels of PTK7 and via the macropinocytosis pathway, which induced cytotoxicity after GEM cleavage from PTK7-GEMs respond to the intracellular phosphatase. Moreover, PTK7-GEMs showed stronger anti-tumor efficacy and excellent biosafety in three types of tumor xenograft mice models.These results demonstrated that PTK7-GEMs is a successful targeted aptamer-drug conjugates strategy (APDCs) to treat BC, which will provide new directions for the precision treatment of BC in the field of biomarker-oriented tumor targeted therapy.