A Numerical Approach for Predicting the Springback of Intersecting High-Stiffened Integral Panel in Spherical Die Forming

Qiyuan He,Weidong Li,Min Wan,Cailing Li,Chao Cui 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.23 No.6

Taking advantage of the high specific strength, structural efficiency, and rigidity of spherical multi-intersecting high-stiffened integral panels, they have been used on a manned space station as the main load-bearing structure. Due to their large size and complex structure, a new incremental die forming approach was proposed, where the panel is pressed by a relatively small die at devised positions multiple times in proper order. However, the springback behavior of the panel after each depression is extremely complicated due to the interactions between multi-intersecting ribs. In this paper, a numerical approach of springback prediction for a typical intersecting stiffened panel in spherical die forming was proposed and the corresponding algorithm was developed. The approach quantifi es the influence between multi-intersecting ribs by a novel defi nition of a bending neutral layer on the panel: the 3-D springback of whole panel is equivalent to the 2-D springback of the ribs. The strain component led by skin deformation and its elastic release are considered. A plasticity model with a nonlinear strain hardening of material was adopted. The approach was employed to predict the springback of panels with different forming radii, different rib sizes, and local large-rigidity structures. A rapid springback compensation based on the approach was achieved. The calculated results are in strong agreement with the results of FEM simulations based on ABAQUS software and experiments, accurately predicting profiles error within 2 mm.

Phylogenetic Analysis of 16S rDNA Sequences Manifest Rumen Bacterial Diversity in Gayals (Bos frontalis) Fed Fresh Bamboo Leaves and Twigs (Sinarumdinaria)

Deng, Weidong,Wanapat, Metha,Ma, Songcheng,Chen, Jing,Xi, Dongmei,He, Tianbao,Yang, Zhifang,Mao, Huaming Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.7

Six male Gayal (Bos frontalis), approximately two years of age and with a mean live weight of $203{\pm}17$ kg ($mean{\pm}standard\;deviation$), were housed indoors in metabolism cages and fed bamboo (Sinarundinaria) leaves and twigs. After an adjustment period of 24 days of feeding the diet, samples of rumen liquor were obtained for analyses of bacteria in the liquor. The diversity of rumen bacteria was investigated by constructing a 16S rDNA clone library. A total of 147 clones, comprising nearly full length sequences (with a mean length of 1.5 kb) were sequenced and submitted to an on-line similarity search and phylogenetic analysis. Using the criterion of 97% or greater similarity with the sequences of known bacteria, 17 clones were identified as Ruminococcus albus, Butyrivibrio fibrosolvens, Quinella ovalis, Clostridium symbiosium, Succiniclasticum ruminis, Selenomonas ruminantium and Allisonella histaminiformans, respectively. A further 22 clones shared similarity ranging from 90-97% with known bacteria but the similarity in sequences for the remaining 109 clones was less than 90% of those of known bacteria. Using a phylogenetic analysis it was found that the majority of the clones identified (57.1%) were located in the low G+C subdivision, with most of the remainder (42.2% of clones) located in the Cytophage-Flexibacter-Bacteroides (CFB) phylum and one clone (0.7%) was identified as a Spirochaete. It was apparent that Gayal have a large and diverse range of bacteria in the rumen liquor which differ from those of cattle and other ruminants. This may explain the greater live weights of Gayal, compared to cattle, grazing in the harsh natural environments in which Gayal are located naturally.

Comparison of Gayal (Bos frontalis) and Yunnan Yellow Cattle (Bos taurus): Rumen Function, Digestibilities and Nitrogen Balance during Feeding of Pelleted Lucerne (Medicago sativum)

Deng, Weidong,Wang, Liping,Ma, Songcheng,Jin, Bo,He, Tianbao,Yang, Zhifang,Mao, Huaming,Wanapat, Metha Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.6

Three male Gayal (Bos frontalis) and three male Yunnan Yellow cattle (Bos taurus) were fed pelleted lucerne and measurements made of digestibility, nitrogen utilisation, rumen fermentation and microbial population and key plasma metabolites. Total actual dry matter intake was similar but when expressed in terms of live weight or metabolic live weight feed intakes were significantly higher (p<0.05) for Gayal than cattle. Apparent digestibilities of dry matter, organic matter, fibre and dietary nitrogen were similar for both Gayal and cattle. Rumen ammonia nitrogen and total volatile fatty acids were significantly higher (p<0.05) for Gayal than cattle and total numbers of viable rumen bacteria, cellulolytic and amylolytic bacteria, but not proteolytic bacteria nor protozoa, were significantly greater (p<0.05) for Gayal than cattle. Although Gayal have a different rumen ecology to cattle, similar digestive parameters were exhibited. Further research is required to establish relationship between rumen ecology and digestive parameters.

Insect cytokine growth-blocking peptide may regulate density-dependent phase trait of cuticular melanization in the larval armyworm, Mythimna separata

Zhang Yingchao,He Juan,Zhang Yuxia,Li Yue,Yu Yang,Jiang Xingfu,Pan Weidong 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.2

Growth-blocking peptide (GBP) is a 25 amino acid insect cytokine found in lepidopteran insects that has diverse biological activities such as larval growth regulation, paralysis induction, cell proliferation and stimulation of immune cells. Density-dependent phase polyphenism is a phenomenon of phenotypic plasticity in which the expression of a variety of traits can be affected by local population density. In the present study, the armyworm Mythimna separata larvae with four rearing densities (1 larva/vial, 2 larvae/vial, 4 larvae/vial and 6 larvae/vial) were tested for cuticular melanization and body weight throughout the third-fifth instar, and the functional role of GBP in regulating the changes was investigated. The results indicated that when reared at high densities, the larvae exhibited less body weight and more degree of cuticular melanization than larvae reared at low densities. The gene expression of GBP in armyworm larvae showed an initial rise and then decline trend with increased rearing densities in the third to fifth instar. Compared with control, more degree of cuticular melanization was observed in GBP-injected larvae (500 ng/larva in volume 50 μL) than that in Ringer’s solution-injected counterparts. Furthermore, the gene expression level of dopa decarboxylase and prophenoloxidase increased significantly in GBP-injected fifth instar larvae from 6 h to 12 h after injection, suggesting the role of GBP in modulating density-dependent phase trait of armyworm cuticular melanization.

Hsp20 Promotes Endothelial Progenitor Cell Angiogenesis via Activation of PI3K/Akt Signaling Pathway under Hypoxia

Han Zhiqi,He Xuan,Feng Yuan,Jiang Weidong,Zhou Nuo,Huang Xuanping 한국조직공학과 재생의학회 2022 조직공학과 재생의학 Vol.19 No.6

BACKGROUND: Mandibular distraction osteogenesis (MDO) is a kind of endogenous tissue engineering technology that lengthens the jaw and opens airway so that a patient can breathe safely and comfortably on his or her own. Endothelial progenitor cells (EPCs) are crucial for MDO-related angiogenesis. Moreover, emerging evidence suggests that heat shock protein 20 (Hsp20) modulates angiogenesis under hypoxic conditions. However, the specific role of Hsp20 in EPCs, in the context of MDO, is not yet known. The aim of this study was to explore the expression of Hsp20 during MDO and the effects of Hsp20 on EPCs under hypoxia. METHODS: Mandibular distraction osteogenesis and mandibular bone defect (MBD) canine model were established. The expression of CD34, CD133, HIF-1a, and Hsp20 in callus was detected by immunofluorescence on day 14 after surgery. Canine bone marrow EPCs were cultured, with or without optimal cobalt chloride (CoCl2) concentration. Hypoxic effects, caused by CoCl2, were evaluated by means of the cell cycle, cell apoptosis, transwell cell migration, and tube formation assays. The Hsp20/KDR/PI3K/Akt expression levels were evaluated via immunofluorescence, RT-qPCR, and western blot. Next, EPCs were incorporated with either Hsp20-overexpression or Hsp20-siRNA lentivirus. The resulting effects were evaluated as described above. RESULTS: CD34, CD133, HIF-1a, and Hsp20 were displayed more positive in the callus of MDO compared with MBD. In addition, hypoxic conditions, generated by 0.1 mM CoCl2, in canine EPCs, accelerated cell proliferation, migration, tube formation, and Hsp20 expression. Hsp20 overexpression in EPCs significantly stimulated cell proliferation, migration, and tube formation, whereas Hsp20 inhibition produced the opposite effect. Additionally, the molecular mechanism was partly dependent on the KDR/PI3K/Akt pathway. CONCLUSION: In summary, herein, we present a novel mechanism of Hsp20-mediated regulation of canine EPCs via Akt activation in a hypoxic microenvironment.

Smart Mobile Gateway: Technical Challenges for Converged Wireless Sensor Networks and Mobile Cellular Networks

Lianhai Shan,Weidong Fang,Yunzhou Qiu,Wei He,Yanzan Sun 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.9

With the continued requirement of internet of things (IoT) development, many researchers focused on developing access and routing algorithms optimization of wireless sensor networks (WSNs) for communications quality guarantee, but less research has focused on the optimization of WSNs based on the mobile cellular networks (MCNs) assist. In this paper, we propose a convergence architecture of WSN and MCN for IoT applications, especially on the smart user equipment (UE) acting as a mobile gateway for WSN data transmission. And then, we investigate system application requirement for IoT. Finally, we discuss the key technical challenges and research points based on an analysis of smart gateway.

Formation of Hyperbranched Amphiphilic Terpolymers and Unimolecular Micelles in One-pot Copolymerization

Xu Wang,Lianwei Li,Weidong He,Chi Wu 한국고분자학회 2016 한국고분자학회 학술대회 연구논문 초록집 Vol.41 No.2

Differentiation of cystic biliary atresia and choledochal cysts using prenatal ultrasonography

Lizhu Chen,Fujiao He,Kaihui Zeng,Bing Wang,Jingyu Li,Dan Zhao,Zeyu Yang,Weidong Ren 대한초음파의학회 2022 ULTRASONOGRAPHY Vol.41 No.1

Purpose: This study explored the performance of prenatal ultrasonography in the differential diagnosis of cystic biliary atresia (CBA) and choledochal cyst (CC). Methods: Fetuses diagnosed with hepatic hilar cyst in the second trimester were included in this study. A series of prenatal ultrasound examinations were performed in the second and third trimesters. The diameter of the gallbladder (GB) and hepatic cyst were measured, as well as the wall thickness of the GB. The GB-cyst connection, visibility of the right hepatic artery (RHA), and other concomitant abnormalities were carefully evaluated. A neonatal transabdominal ultrasound examination was performed within 1 week after birth, and clinical data were followed up to 6 months after birth. Results: Between January 1, 2016 and January 31, 2020, 53 fetuses diagnosed with hepatic hilar cyst were recruited. Eight were excluded because they were lost to follow-up. Among the 45 cases included in this study, 10 were diagnosed with CBA and 35 with CC after birth. Statistically significant differences were found in GB width, wall thickness, change in GB width, change in cyst length, GB-cyst connection, and RHA visibility between the CBA and CC groups. GB width showed the best diagnostic performance with an area under the curve (AUC) of 0.899. The combination of GB width, GB wall thickness, and GB-cyst connection yielded a comparable AUC of 0.971. Conclusion: The GB should be carefully evaluated in fetuses with hepatic hilar cyst. Prenatal ultrasound findings could provide suggestive parameters for the differential diagnosis of CBA from CC. Purpose: This study explored the performance of prenatal ultrasonography in the differential diagnosis of cystic biliary atresia (CBA) and choledochal cyst (CC).Methods: Fetuses diagnosed with hepatic hilar cyst in the second trimester were included in this study. A series of prenatal ultrasound examinations were performed in the second and third trimesters. The diameter of the gallbladder (GB) and hepatic cyst were measured, as well as the wall thickness of the GB. The GB-cyst connection, visibility of the right hepatic artery (RHA), and other concomitant abnormalities were carefully evaluated. A neonatal transabdominal ultrasound examination was performed within 1 week after birth, and clinical data were followed up to 6 months after birth.Results: Between January 1, 2016 and January 31, 2020, 53 fetuses diagnosed with hepatic hilar cyst were recruited. Eight were excluded because they were lost to follow-up. Among the 45 cases included in this study, 10 were diagnosed with CBA and 35 with CC after birth. Statistically significant differences were found in GB width, wall thickness, change in GB width, change in cyst length, GB-cyst connection, and RHA visibility between the CBA and CC groups. GB width showed the best diagnostic performance with an area under the curve (AUC) of 0.899. The combination of GB width, GB wall thickness, and GB-cyst connection yielded a comparable AUC of 0.971.Conclusion: The GB should be carefully evaluated in fetuses with hepatic hilar cyst. Prenatal ultrasound findings could provide suggestive parameters for the differential diagnosis of CBA from CC.

Multi-objective optimization of cycloidal gear based on segmental modification of pressure angle

Yinghui Zhang,JinYong Huang,Weidong He 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.7

In order to get the optimal profile of cycloid gear after sectional modification, a multi-objective optimization design method is proposed that considers both the modification parameters and macro-parameters of the cycloid gear. An algorithm of meshing force, meshing efficiency and anti-gluing ability between the cycloid gear and the pin gear was derived, and the related independent parameters were extracted as optimization variables. Taking high efficiency, high strength and light weight as the objective, the mathematical models of doubleobjective and three-objective optimization were established, and the influence of key design variable on the objective function was analyzed, and NSGA-II multi-objective genetic algorithm was used to solve the Pareto optimal solution of the optimization mathematical model. Results show that the optimized parameters can significantly improve the meshing efficiency, reduce the volume and meet the design requirements of high strength, high efficiency and lightweight on the premise of ensuring the strength of cycloid gear surface.

A prevalence survey of Wolbachia in Polytremis fukia (Lepidoptera: Hesperiidae)

Weibin Jiang,Yajuan Wu,Haiyan He,Jianqing Zhu,Weidong Yu 한국응용곤충학회 2016 Journal of Asia-Pacific Entomology Vol.19 No.2

Wolbachia are endosymbiotic bacteria that infect arthropod and nematode hosts. Only a few studies have been made on Wolbachia in butterflies. In this study, we identified and determined the molecular characteristics of Wolbachia strains in Polytremis fukia (Lepidoptera: Hesperiidae), from seven locations in China. We also sequenced three portions of the mitochondrial DNA from the individuals of P. fukia to infer the effect of Wolbachia on host mitochondrial variation. The results show that 47% (15/32) are Wolbachia positive among all specimens. The infection rates in female and male are 69% (11/16) and 25% (4/16). Phylogenetic analysis of variation in the ftsZ gene from the two strains of Wolbachia (wFuk1 and wFuk2) showed they belonged to supergroup A. On the phylogeny of the mitochondrialDNA fromP. fukia, the sequences are split into three clades. Clade I and II are consistent with the distribution of geographical population. Clade III consists of eight females invariably infected with wFuk1which showed aweak association existed between mitochondrial DNA haplotypes andwFuk1 infection status.