Investigation on shaping machining method for deep hole keyway based on on-line symmetry detection and compensation

Chunhua Zhao,Zhipeng Liang,Huawei Zhou,Hongling Qin 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.3

Machining of deep hole keyway often suffers from low processing accuracy, low processing symmetry degree between keyway and the reference plane and is difficult to control. In order to enhance the processing quality, a mathematical model of space symmetry error was established based on space projection, orthogonal combination and linear fitting methods so as to study rotatable and shift-able space objects. The space symmetry error was separated into included angle error and displacement error between the fitting straight line and the benchmark line. Through included angle rotation and location measurement along with quantitative translation, the space symmetry error compensation was realized. On the basis of the proposed methods, a Double combined manual self-centering fixture (DCMSF) was designed to realize the radial self-centering and axial location for effective clamping of deep hole keyway, and the reference plane of builtin straight slot was derived out to make it detectable and controllable. Meanwhile, an Online multi-degree of freedom symmetry detection device (OMFSDD) and corresponding Numerical control (NC) programs were also designed for automatic detection and control of symmetry error. Subsequently, mass production of high symmetric deep hole keyway were realized by means of NC gear shaper servo control of rotating shaft angle compensation and bi-directional cutter back-off amount translation compensation, and combination of NC control of fixed angle processing. Deep hole keyway processing experiments indicate that the proposed method can steadily keep the symmetry within 0.03 mm. Thus, the rationality and accuracy of the proposed method was validated which provides a novel approach to high precision deep hole keyway processing.

Study on sensitivity of modal parameters for suspension bridges

Liu, Chunhua,Wang, Ton-Lo,Qin, Quan Techno-Press 1999 Structural Engineering and Mechanics, An Int'l Jou Vol.8 No.5

Safety monitoring systems of structures generally resort to detecting possible changes of dynamic system parameters. Sensitivity analysis of these dynamic system parameters may implement these techniques. Conventional structural eigenvalue problems are discussed in the scope of those systems with deterministic parameters. Large and flexible structures, such as suspension bridges, actually possess stochastic material properties and these random properties unavoidably affect the dynamic system parameters. The sensitivity matrix of structural modal parameters to basic design variables has been established in this paper. Moreover, second order statistics of natural frequencies due to the randomness of material properties have been discussed. It is concluded from numerical analysis of a modem suspension bridge that although the second order statistics of frequencies are small relatively to the change of basic design variables, such as density of mass and modulus of elasticity, the sensitivities of modal parameters to these variables at different locations change in magnitude.

Hypoxia-induced PLOD2 regulates invasion and epithelial-mesenchymal transition in endometrial carcinoma cells

Junhui Wan,Junli Qin,Qinyue Cao,Ping Hu,Chunmei Zhong,Chunhua Tu 한국유전학회 2020 Genes & Genomics Vol.42 No.3

Background Procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2) was induced in hypoxia and participated in cancer development. However, the role of PLOD2 in endometrial carcinoma remains unclear. Objective To explore the influences and regulation mechanism of PLOD2 in endometrial carcinoma under hypoxic condition. Methods The small interfering RNA (siRNA) targeting to PLOD2 and pcDNA3.1-PLPD2 were transfected to endometrial carcinoma cells to alter PLOD2 expression. Cell proliferation ability was determined by colony formation assay. Wound healing assay used to detect cell migration ability. Transwell invasion assay was used to detect cell invasion ability. Results PLOD2 and Hypoxia-inducible factor-1α (HIF-1α) were induced by hypoxia. Down-regulation of PLOD2 did not affect endometrial carcinoma cell proliferation ability, while inhibited cell migration, invasion under hypoxic condition. Besides, down-regulation of PLOD2 increased the levels of γ-catenin and E-cadherin and decreased levels of Fibronectin and Snail under hypoxic condition. Down-regulation of PLOD2 also inactivated Src and phosphoinositide 3-kinase (PI3K)/ protein kinase B (Akt) signaling under hypoxic condition. The promoting effects of PLOD2 overexpression on migration, invasion and epithelial-mesenchymal transition (EMT) of endometrial carcinoma cells were reversed by Akt inhibitor (MK2206) under hypoxic condition. Conclusion PLOD2 expression was increased in endometrial carcinoma cells under hypoxic condition. PLOD2 modulated migration, invasion, and EMT of endometrial carcinoma cells via PI3K/Akt signaling. PLOD2 may be a potential therapeutic target for endometrial carcinoma.

Polymorphisms in Epigenetic and Meat Quality Related Genes in Fourteen Cattle Breeds and Association with Beef Quality and Carcass Traits

Liu, Xuan,Usman, Tahir,Wang, Yachun,Wang, Zezhao,Xu, Xianzhou,Wu, Meng,Zhang, Yi,Zhang, Xu,Li, Qiang,Liu, Lin,Shi, Wanhai,Qin, Chunhua,Geng, Fanjun,Wang, Congyong,Tan, Rui,Huang, Xixia,Liu, Airong,Wu, Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.4

Improvement for carcass traits related to beef quality is the key concern in beef production. Recent reports found that epigenetics mediates the interaction of individuals with environment and nutrition. The present study was designed to analyze the genetic effect of single nucleotide polymorphisms (SNPs) in seven epigenetic-related genes (DNMT1, DNMT3a, DNMT3b, DNMT3L, Ago1, Ago2, and HDAC5) and two meat quality candidate genes (CAPN1 and PRKAG3) on fourteen carcass traits related to beef quality in a Snow Dragon beef population, and also to identify SNPs in a total of fourteen cattle populations. Sixteen SNPs were identified and genotyped in 383 individuals sampled from the 14 cattle breeds, which included 147 samples from the Snow Dragon beef population. Data analysis showed significant association of 8 SNPs within 4 genes related to carcass and/or meat quality traits in the beef populations. SNP1 (13154420A>G) in exon 17 of DNMT1 was significantly associated with rib-eye width and lean meat color score (p<0.05). A novel SNP (SNP4, 76198537A>G) of DNMT3a was significantly associated with six beef quality traits. Those individuals with the wild-type genotype AA of DNMT3a showed an increase in carcass weight, chilled carcass weight, flank thicknesses, chuck short rib thickness, chuck short rib score and in chuck flap weight in contrast to the GG genotype. Five out of six SNPs in DNMT3b gene were significantly associated with three beef quality traits. SNP15 (45219258C>T) in CAPN1 was significantly associated with chuck short rib thickness and lean meat color score (p<0.05). The significant effect of SNP15 on lean meat color score individually and in combination with each of other 14 SNPs qualify this SNP to be used as potential marker for improving the trait. In addition, the frequencies of most wild-type alleles were higher than those of the mutant alleles in the native and foreign cattle breeds. Seven SNPs were identified in the epigenetic-related genes. The SNP15 in CAPN1 could be used as a powerful genetic marker in selection programs for beef quality improvement in the Snow Dragon Beef population.

Polymorphisms in Epigenetic and Meat Quality Related Genes in Fourteen Cattle Breeds and Association with Beef Quality and Carcass Traits

Xuan Liu,Tahir Usman,Yachun Wang,Zezhao Wang,Xianzhou Xu,Meng Wu,Yi Zhang,Xu Zhang,Qiang Li,Lin Liu,Wanhai Shi,Chunhua Qin,Fanjun Geng,Congyong Wang,Rui Tan,Xixia Huang,Airong Liu,Hongjun Wu,Shixin Ta 아세아·태평양축산학회 2015 Animal Bioscience Vol.28 No.4

Improvement for carcass traits related to beef quality is the key concern in beef production. Recent reports found that epigenetics mediates the interaction of individuals with environment and nutrition. The present study was designed to analyze the genetic effect of single nucleotide polymorphisms (SNPs) in seven epigenetic-related genes (DNMT1, DNMT3a, DNMT3b, DNMT3L, Ago1, Ago2, and HDAC5) and two meat quality candidate genes (CAPN1 and PRKAG3) on fourteen carcass traits related to beef quality in a Snow Dragon beef population, and also to identify SNPs in a total of fourteen cattle populations. Sixteen SNPs were identified and genotyped in 383 individuals sampled from the 14 cattle breeds, which included 147 samples from the Snow Dragon beef population. Data analysis showed significant association of 8 SNPs within 4 genes related to carcass and/or meat quality traits in the beef populations. SNP1 (13154420A>G) in exon 17 of DNMT1 was significantly associated with rib-eye width and lean meat color score (p<0.05). A novel SNP (SNP4, 76198537A>G) of DNMT3a was significantly associated with six beef quality traits. Those individuals with the wild-type genotype AA of DNMT3a showed an increase in carcass weight, chilled carcass weight, flank thicknesses, chuck short rib thickness, chuck short rib score and in chuck flap weight in contrast to the GG genotype. Five out of six SNPs in DNMT3b gene were significantly associated with three beef quality traits. SNP15 (45219258C>T) in CAPN1 was significantly associated with chuck short rib thickness and lean meat color score (p<0.05). The significant effect of SNP15 on lean meat color score individually and in combination with each of other 14 SNPs qualify this SNP to be used as potential marker for improving the trait. In addition, the frequencies of most wild-type alleles were higher than those of the mutant alleles in the native and foreign cattle breeds. Seven SNPs were identified in the epigenetic-related genes. The SNP15 in CAPN1 could be used as a powerful genetic marker in selection programs for beef quality improvement in the Snow Dragon Beef population.