Experimental identification of fluid-induced force in labyrinth seals

Wan Fu Zhang,Jian Gang Yang,Hao Cao,Dan Sun 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.10

The seal force is an important factor in turbomachineries. Therefore, the current paper puts forward an expanded seal force identification model. A seal test rig consisting of several sets of seals was prepared. Using the double-plane unbalance force identification theory in rotordynamics, the distributed seal force in the cylinder became equivalent to two selected planes. Considering the complex cylinder vibration with increasing rotating speed and inlet pressure, the cylinder was regarded as a vibration system with 4 degrees of freedom. The 4×4 impedance matrix was tested at the two selected planes using a shaker in two orthogonal directions. The equivalent seal force can be obtained by multiplying the impedance matrix with the measured change in the cylinder vibration. In the seal rig, tests were performed on the influence of inlet pressure, rotating speed, eccentricity ratio, rotor vibration, and clearance. The seal force increases almost linearly with the increasing inlet pressure, eccentricity ratio, and vibration amplitude. Furthermore, the seal force is strongly sensitive to the change in clearance between the cylinder and the rotating rotor. The phase difference between the seal force and the vibration influences the work done. If the phase difference is nearly 90°, then the work is at maximum. Moreover, the seal force applies positive force on the cylinder and negative force on the rotor.

SNPs of Excision Repair Cross Complementing Group 5 and Gastric Cancer Risk in Chinese Populations

Yang, Wan-Guang,Zhang, Shan-Feng,Chen, Ju-Wu,Li, Li,Wang, Wan-Peng,Zhang, Xie-Fu Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.12

We conducted a case-control study to determine the association between several potential SNPs of excision repair cross complementing group 5 (XPG) and gastric cancer susceptibility, and roles of XPG polymorphisms in combination with H.pylori infection in determining risk of gastric cancer. In our study, we collected 337 newly diagnosed gastric cancer cases and 347 health controls. Three SNPs of XPG, rs2296147T>C, rs2094258C>T and rs873601G>A, were genotyped using the Taqman real-time PCR method with a 7900 HT sequence detector system. H. pylori infection was diagnosed by ELISA. By multivariate logistic regression analysis, the rs2296147 CC genotype was associated with a decreased risk of gastric cancer (OR=0.52, 95% CI=0.27-0.97), and rs2094258 TT was associated with elevated risk (OR=2.13, 95% CI=1.22-3.35). Positive H.pylori individuals with rs2094258 TT genotypes demonstrated increased risk of gastric cancer (OR=2.13, 95% CI=1.22-3.35), while rs2296147 CC was associated with lower risk among patients with negative H.pylori (OR=0.45, 95%CI=0.22-0.89). Our findings suggested that XPG polymorphisms might contribute to risk of gastric cancer among Chinese populations, but the effect needs to be further validated by larger sample size studies.

Association of CYP2E1 and NAT2 Polymorphisms with Lung Cancer Susceptibility among Mongolian and Han Populations in the Inner Mongolian Region

Zhang, Jing-Wen,Yu, Wan-Jia,Sheng, Xiao-Min,Chang, Fu-Hou,Bai, Tu-Ya,Lv, Xiao-Li,Wang, Guang,Liu, Su-Zhen Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.21

Purpose: To explore associations of CYP2E1 and NAT2 polymorphisms with lung cancer susceptibility among Mongolian and Han populations in the Inner Mongolian region. Materials and Methods: CYP2E1 and NAT2 polymorphisms were detected by PCR-RFLP in 930 lung cancer patients and 1000 controls. Results: (1) Disequilibrium of the distribution of NAT2 polymorphism was found in lung cancer patients among Han and Mongolian populations (p=0.031). (2) Lung cancer risk was higher in individuals with c1, D allele of CYP2E1 RsaI/PstI, DraI polymorphisms and slow acetylation of NAT2 (c1 compared with c2, OR=1.382, 95%CI: 1.178-1.587, p=0.003; D compared with C, OR=1.241, 95%CI: 1.053-1.419, P<0.001; slow acetylation compared with rapid acetylation, OR=1.359, 95%CI:1.042-1.768, p=0.056) (3) Compared with c2/c2 and rapid acetylation, c1/c1 together with slow acetylation synergetically increased risk of lung cancer 2.83 fold. (4) Smokers with CYP2E1 c1/c1, DD, and NAT2 slow acetylation have 2.365, 1.916, 1.841 fold lung cancer risk than others with c2/c2, CC and NAT2 rapid acetylation, respectively. (5) Han smokers with NAT2 slow acetylation have 1.974 fold lung cancer risk than others with rapid acetylation. Conclusions: Disequilibrium distribution of NAT2 polymorphism was found in lung cancer patients among Han and Mongolian populations. Besides, Han smokers with NAT2 slow acetylation may have higher lung cancer risk compared with rapid acetylation couterparts. CYP2E1 c1/c1, DD and NAT2 slow acetylation, especially combined with smoking, contributes to the development of lung cancer. CYP2E1 c1/c1 or DD genotype and NAT2 slow acetylation have strong synergistic action in increasing lung cancer risk.

Oxidation and Corrosion Behavior of Nanolaminated MAX-Phase Ti₂AlC Film Synthesized by High-Power Impulse Magnetron Sputtering and Annealing

Fu, Jianjian,Zhang, Teng Fei,Xia, Qixun,Lim, Sung-Hwan,Wan, Zhixin,Lee, Taeg-Woo,Kim, Kwang Ho Hindawi Limited 2015 Journal of nanomaterials Vol.2015 No.-

<P>Nanolaminated MAX-phase Ti2AlC thin films were synthesized by high-power impulse magnetron sputtering (HiPIMS) from a MAX-phase Ti2AlC target. The amorphous matrix Ti-Al-C films were deposited at room temperature, while the MAX-phase Ti2AlC films were obtained through annealing process of the as-deposited amorphous matrix films. The microstructure, oxidation resistance, and corrosion behavior of these two films were comparatively investigated. The results indicated that the MAX-phase Ti2AlC films had superior antioxidation and anticorrosion properties than the amorphous matrix Ti-Al-C films, which is attributed to the rapid formation of dense Al2O3layer on the top of MAX-phase Ti2AlC films because of the rapid diffusion of Al atoms in the typical nanolaminated structure of MAX phase.</P>

Effect of Diallyl Trisulfide on Human Ovarian Cancer SKOV-3/DDP Cell Apoptosis

Wan, Hui-Fang,Yu, Le-Han,Wu, Jin-Lan,Tu, Shuo,Zhu, Wie-Feng,Zhang, Xia-Li,Wan, Fu-Sheng Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Aim: To investigate the effects of diallyl trisulfide (DT) on apoptosis of cisplatin (DDP)-resistant human epithelial ovarian cancer SKOV-3 cells (SKOV-3/DDP), and the role of p53 upregulated modulator of apoptosis (PUMA). Methods: SKOV-3/DDP cells were randomly divided into control, DT, DPP and DPP+DT groups, which were treated with DT or combined DT and DDP. All cells were incubated for 48 h. and apoptosis rates were assessed by flow cytometry. mRNA and protein expression of PUMA, Bax and Bcl-2 was determined by RT-PCR and Western blot assays, respectively. Results: Compared with control group, the apoptosis rates of SKOV-3/DDP cells in DT groups were obviously increased, with dose-dependence (P < 0.05), the mRNA and protein expressions of PUMA, Bax also being up-regulated (P < 0.05), while those of Bcl-2 were down-regulated (P < 0.05). Compared with DT groups, the apoptosis rate in the DDP+DT group was significantly increased (P < 0.05). After knockdown of PUMA with specific siRNA, the apoptosis rate of SKOV-3/DDP cells was obviously decreased (P < 0.05). Conclusion: DT can promote the apoptosis of SKOV-3/DDP cells with PUMA playing a critical role.

Transcriptional analysis reveals formation of axillary solitary hook in vine plant Uncaria rhynchophylla

Wan Lingyun,Pan Limei,Song Lisha,Fu Jine,Huang Qiulan,Ji Xiaowen,Wei Shugen,Zhang Zhanjiang 한국식물생명공학회 2023 Plant biotechnology reports Vol.17 No.5

The hook of Uncaria rhynchophylla is an important external phenotype representing the quality of Gou-Teng. The hook formation pattern of U. rhynchophylla displays a unique feature that solitary hook and opposite hooks alternately occur in the leaf axils forming a liner series. The solitary hook only grows on the lower side of the leaf axil, resulting from the decline in the total yield of hooks. However, the reasons for solitary hook formation in U. rhynchophylla are not clear. Therefore, a survey on the molecular mechanisms of solitary hook formation needs to be performed urgently. We obtained 250.67 million high-quality clean reads from the lower side of axillary stem segments (HS) and the upper side of axillary stem segments (HSCK) libraries. We detected 42 DEGs (differentially expressed genes) between HS and HSCK libraries; 11 were down-regulated, and 31 were up-regulated. Gene ontology functional classification of the DEGs indicated that they included two genes that encoded LAZY1 related to the regulation of polar auxin transport, two genes that encoded AUX/IAA and AP2/ERF related to plant hormone signaling transduction, and two genes that encoded F3H related to the flavone synthase activity. These six genes were associated with lateral polar auxin transport (PAT) regulation, and their expression level had a high correlation with the pattern of IAA distribution upon gravity stimulation. And the inhibition of solitary hook development was observed after treatment with N-1-naphthylphthalamic acid (NPA) or quercetin, which was known as the polar auxin inhibitor. The above findings might provide new information about the molecular mechanisms of regulation of lateral PAT in the axillary bud development process under gravity.

Molecular cloning of novel α-gliadin genes from Crithopsis delileana and the evolution analysis with those from Triticeae

Zhi-Fu Guo,Xiang-Yu Long,Pan Dong,Yu-Ming Wei,Li-Ping Bai,Xiao-Xuan Dang,Hao-Lei Wan,Li-Jun Zhang,You-Liang Zheng 한국유전학회 2011 Genes & Genomics Vol.33 No.2

The α-gliadins from Crithopsis delileana (Schult) Roshev (2n=2x=14, KK) were investigated by Acid polyacrylamide gel electrophoresis (A-PAGE) analysis. It was indicated that the electrophoresis mobility of gliadins from C.delileana had obvious difference with those from common wheat in α, γand ω region. Using primers designed from published sequences of α-gliadin genes, three α-gliadin genes were isolated from C. delileana, which were designated as gli-ka1,gli-ka2 and gli-ka3, respectively. Two in-frame stop codons were found in the coding sequences of gli-ka3, indicating that gli-ka3 could be a pseudogene. The gli-ka2 was a gliadin with an odd number of cysteines, resulting from a non-synonymous mutation. This change might lead to the interactive behavior of gli-ka2. Three α-gliadin genes of C. delileana had the similar but not identical primary structures to the corresponding gene sequences from other wheat related species. By the alignment of α-gliadin genes from Triticeae,phylogenetic analysis indicated that three α-gliadin genes of C. delileana clustered together with all α-gliadin genes from Ee genome of Lophopyrum elongatum by an interior paralleled branch.

Application of the energy balance method to a nonlinear oscillator arising in the microelectromechanical system (MEMS)

Yiming Fu,Jin Zhang,Liangjiao Wan 한국물리학회 2011 Current Applied Physics Vol.11 No.3

In this paper, the energy balance method has been successfully used to study a nonlinear oscillator arising in the microbeam-based microelectromechanical system (MEMS). Firstly, the governing equation of the free vibration of a microbeam is governed based on the Euler―Bernoilli hypothesis where the midplane stretching effect and distributed electrostatic force are both considered. Then this PDE problem is simplified into an ODE problem by using the Galerkin method. Finally, the nonlinear ODE equation is solved by a powerful mathematical tool, the energy balance method. The good agreement of results got from energy balance method with results from fourth-order Runge―Kutta method indicates that the obtained period is of high accuracy.

A novel pattern recognition protein of the Chinese oak silkmoth, Antheraea pernyi, is involved in the pro-PO activating system

Xia Lu Wan,Zhang Jing Hai,Ying Chen,You Lei Ma,Wen Jun Zou,Guo Yuan Ding,Wei Li,Ming Yi Zhao,Chun Fu Wu 생화학분자생물학회(구 한국생화학분자생물학회) 2013 BMB Reports Vol.46 No.7

RNA Interference-Based Transgenic Maize Resistant to Maize Dwarf Mosaic Virus

Zhi-Yong Zhang,Feng-Ling Fu,Lin Gou,Han-Guang Wang,Wan-Chen Li 한국식물학회 2010 Journal of Plant Biology Vol.52 No.4

Maize dwarf mosaic virus (MDMV) is a widespread pathogenic virus that causes serious loss of yield in maize (Zea mays). RNA interference (RNAi) triggered by hairpin RNA (hpRNA) transcribed from a transgenic inverted-repeat sequence is an effective way to defend against viruses in plants. In this study, an hpRNA expression vector containing a sense arm and an antisense arm of 150 bp separated by an intron of the maize actin gene was constructed to target the P1 protein (protease)gene of MDMV and used to transform Agrobacterium tumefaciens strain EHA105. The transformed Agrobacterium strain was used to transform maize embryonic calli isolated from immature embryos by an improved culture technique. In all, 46 plants were regenerated after stringent hygromycin B selection, and 18 of them were certified to be positive by PCR amplification. Of these positive plants,13 were grown to produce offspring, and nine were identified by Southern blotting to have the transgene integrated with one or two copies. The resistance of three T2 lines was evaluated in a field trial of dual MDMV inoculation in two environments and was found to be improved compared with the non-transformed control. The disease indexes of the transgenic plant lines h2, 13, and h1were not significantly different from the highly resistant control line H9-21. The viral titers of the inoculated plants were detected by double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA), and the result was in accord with the resistance evaluated in the field trial. The addition of uniconazole S3307 (0.25 mgl−1) and ABT rootpromoting powder (0.5 mgl−1) showed a significant improvement of hardening in regenerated plantlets, which were stronger and generated a better fibrous root system than the control. This improvement could facilitate the transgenic operation of maize.