A comparative study of fatigue behavior between S-shaped and involute POM gears

Wu Ruo,Wei Peitang,Lu Zehua,Liu Huaiju,Zorko Damijan,Xie Huaijie 한국CDE학회 2022 Journal of computational design and engineering Vol.9 No.6

Applications of polymer gears have been gradually expanding from motion transmission to power transmission fields. Design of new gear teeth profiles plays a crucial role in meeting the requirement of replacing metallic gears with polymer ones. This work develops a computational framework consisting of tooth profile generation and fatigue life prediction of S-shaped and involute POM gears. The contact and bending fatigue performances of S-shaped and involute POM gears under oil lubrication are comparatively studied. It is found that the S-shaped profile reduces the tooth root stress by 25% and significantly improves the bending fatigue life by 10 times compared with the involute profile, especially under medium or high loading levels. Furthermore, the S-shaped gear with a single circular-filleted root curve benefits a 20% reduction of tooth root stress and a 30% increase in bending fatigue life compared to a double circular-filleted root curve S-shaped gear.

Airfoil optimization based on multi-objective bayesian

Ruo-Lin Liu,Qiang Zhao,Xian-Jun He,Xin-Yi Yuan,Wei-Tao Wu,Ming-Yu Wu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.11

This paper proposes a novel aerodynamic optimization framework for airfoils, which utilizes OpenFOAM, an open-source computational fluid dynamics software, and a Bayesian network to achieve efficient optimization of airfoil aerodynamic performance. Aerodynamic analysis of the NACA 4-digit airfoil was performed by adopting the Spalart-Allmaras turbulence model to solve the Reynolds-averaged Navier–Stokes equations. With the use of this framework, the optimal lift-to-drag ratio can be found by using a small number of objective evaluations. The optimal angle of attack and aerodynamic shape can be obtained under different thicknesses. Finally, after various aerodynamic objectives are arranged and combined, the Pareto fronts were obtained by the multi-objective Bayesian algorithm. Compared with the original NACA four-digit airfoil, the lift-to-drag ratio of the airfoil after single-objective optimization is greatly improved as the thickness increases, and the airfoil after multi-objective optimization achieves different Pareto sets according to different sailing phases.

KLF4 Expression Correlates with the Degree of Differentiation in Colorectal Cancer

( Ruo Lei Hu ),( Yan Zuo ),( Li Zuo ),( Chao Liu ),( Su Mei Zhang ),( Qiang Wu ),( Qing Zhou ),( Shu Yu Gui ),( Wei Wei ),( Yuan Wang ) 대한소화기기능성질환·운동학회 2011 Gut and Liver Vol.5 No.2

Background/Aims: Kruppel-like factor 4 (KLF4) is an epithelial-specifi c transcription factor primarily expressed in the gastrointestinal tract that mediates growth arrest in the colonic epithelium. We tried to find whether KLF4 expression is associated with the progression and differentiation of colorectal cancer. Methods: We detected KLF4 expression in 109 colorectal specimens (40 normal appearing mucosa, 7 adenomas, and 62 carcinomas) by immunohistochemistry using a tissue microarray. Western blot and RT-PCR analyses were also performed. Results: The upregulation of KLF4 expression in carcinoma tissue was statistically significant (p<0.05) when compared to normal appearing mucosa. The negative and weak positive staining rates in normal appearing mucosa, adenoma, and carcinoma were 42.5%, 71.4%, and 82.3%, respectively, indicating a decreased degree of KLF4 expression over the course of progressive transformation of normal cells into malignant derivatives. KLF4 protein levels showed no correlation with sex, age, or metastatic state (p>0.05), while KLF4 protein expression correlated with the diagnostic stage (p<0.05). Furthermore, strong KLF4 staining was detected in 22.9% (11/48) and 0% (0/14) of well/moderately and poorly differentiated colorectal cancers, respectively. Our results clearly indicate that KLF4 protein expression signifi cantly correlates with the degree of differentiation in colorectal cancers (p<0.05). KLF4 expression in RKO cells is also upregulated by butyrate, an inducer of differentiation. Conclusions: Downregulation of KLF4 expression may lead to more poorly differentiated tumors. (Gut Liver 2011;5:154-159)

Mechanical Behavior of Glass Panels Supported by Clamping Joints in Cable Net Facades

Ruo-qiang Feng,Ji-hong Ye,Yue Wu,Shi-zhao Shen 한국강구조학회 2012 International Journal of Steel Structures Vol.12 No.1

In glass panels supported by clamping joints in a cable net facade, the clamping joint restrains movement at the four corners of the glass panel. As a result, the mechanical behavior of the glass panels supported by clamping joints is very different than the behavior of glass panels supported by four hinged corners. Moreover, the deformation in cable net facade is large and nonuniform; thus, the glass panels in cable net facades bear the effects of warping distortion. In this study, a model test and theoretical analysis was conducted to study the mechanical behavior of glass panels supported by clamping joints in a cable net facade. To this end, a cable net facade was designed, and a proper experimental model was constructed. A static mechanical model test was conducted, where the glass stress at different positions in the cable net was measured. A numerical model of the cable net facade was developed, and the results of the experiment and the numerical analysis were compared. Furthermore,the numerical results provided a detailed description of the mechanical behavior of the glass panels in a cable net facade.

Computer simulation of stereochemical structure of biodegradable poly(d,l-lactide-co-l-lactide)

Pei-Hua He,Yan Wu,Ruo-Feng Wu 한국물리학회 2007 Current Applied Physics Vol.7 No.s1

poly(D,L-lactide-co-L-lactide) (PDLLA). The Monte Carlo model is set up according to the reactivity probabilities of two kinds of isomerRR and SS during ring-opening chain propagation. The simulation results for Tetrads and Hexads intensities are in good agreement withexperimental results for13C NMR. Some other important parameters for the stereochemical structure of PDLLA are also obtained fromRun numbers. The inuence of reactivity ratiorand feed ratiop on the stereochemical structure is analyzed and discussed in detail. Thiscomputer simulation method has proved to be a convenient method for establishing structureproperties relationships of certain poly-mers whose stereoregularity can be adjusted, such as PDLLA.

Antioxidant Activities of Novel Small-molecule Polysaccharide Fractions Purified from Portulaca oleracea L.

Yuping Li,Li-Hua Yao,Guan-Jie Wu,Xiao-Fang Pi,Yan-Chun Gong,Ruo-Shong Ye,Chen-Xi Wang 한국식품과학회 2014 Food Science and Biotechnology Vol.23 No.6

Novel small-molecule polysaccharide fractions,named POP II and POP III, were purified from Portulacaoleracea L. with average Mw values of 9.25 and 8.03 kDa,respectively. Monosaccharide analysis revealed that POP IIwas composed of Rha, Ara, Man, Glc, and Gal with molarratios of 1: 1.42: 0.44: 0.88: 1.59. POP III was composedof Rha, Ara, Glc, and Gal with molar ratios of 1: 1.16:0.23: 0.59. The antioxidant activities of the fractions wereevaluated using cell-free and cell-mediated radical generatingsystems. POPII and POP III possessed strong antioxidantactivities in both systems. The 2 novel polysaccharidefractions extracted from P. oleracea L. can be developed asnatural antioxidants for treatment of free radical-relateddiseases.

Pharmacological blockade of cholesterol trafficking by cepharanthine in endothelial cells suppresses angiogenesis and tumor growth

Lyu, Junfang,Yang, Eun Ju,Head, Sarah A.,Ai, Nana,Zhang, Baoyuan,Wu, Changjie,Li, Ruo-Jing,Liu, Yifan,Yang, Chen,Dang, Yongjun,Kwon, Ho Jeong,Ge, Wei,Liu, Jun O.,Shim, Joong Sup Elsevier 2017 Cancer letters Vol.409 No.-

<P><B>Abstract</B></P> <P>Cholesterol is an important modulator of membrane protein function and signaling in endothelial cells, thus making it an emerging target for anti-angiogenic agents. In this study, we employed a phenotypic screen that detects intracellular cholesterol distribution in endothelial cells (HUVEC) and identified 13 existing drugs as cholesterol trafficking inhibitors. Cepharanthine, an approved drug for anti-inflammatory and cancer management use, was amongst the candidates, which was selected for in-depth mechanistic studies to link cholesterol trafficking and angiogenesis. Cepharanthine inhibited the endolysosomal trafficking of free-cholesterol and low-density lipoprotein in HUVEC by binding to Niemann-Pick disease, type C1 (NPC1) protein and increasing the lysosomal pH. The blockade of cholesterol trafficking led to a cholesterol-dependent dissociation of mTOR from the lysosomes and inhibition of its downstream signaling. Cepharanthine inhibited angiogenesis in HUVEC and in zebrafish in a cholesterol-dependent manner. Furthermore, cepharanthine suppressed tumor growth in vivo by inhibiting angiogenesis and it enhanced the antitumor activity of the standard chemotherapy cisplatin in lung and breast cancer xenografts in mice. Altogether, these results strongly support the idea that cholesterol trafficking is a viable drug target for anti-angiogenesis and that the inhibitors identified among existing drugs, such as cepharanthine, could be potential anti-angiogenic and antitumor agents.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A phenotypic screen identified 13 existing drugs, including cepharanthine, as cholesterol trafficking inhibitors. </LI> <LI> Cepharanthine inhibited lysosomal cholesterol trafficking by binding to NPC1 protein and increasing the lysosomal pH. </LI> <LI> The blockade of cholesterol trafficking led to a cholesterol-dependent dissociation of mTOR from the lysosomes. </LI> <LI> Cepharanthine inhibited angiogenesis in HUVEC and in zebrafish in a cholesterol-dependent manner. </LI> <LI> Cepharanthine treatment enhanced the antitumor activity of cisplatin in lung and breast cancer xenografts in mice. </LI> </UL> </P>

Association of XRCC3 Thr241Met Polymorphisms and Gliomas Risk: Evidence from a Meta-analysis

Liang, Hong-Jie,Yan, Yu-Lan,Liu, Zhi-Ming,Chen, Xu,Peng, Qi-Liu,Wang, Jian,Mo, Cui-Ju,Sui, Jing-Zhe,Wu, Jun-Rong,Zhai, Li-Min,Yang, Shi,Li, Tai-Jie,Li, Ruo-Lin,Li, Shan,Qin, Xue Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.7

The relationship between the X-ray repair cross-complementing group 3 (XRCC3) Thr241Met polymorphism and gliomas remains inclusive or controversial. For better understanding of the effect of XRCC3 Thr241Met polymorphism on glioma risk, a meta-analysis was performed. All eligible studies were identified through a search of PubMed, Elsevier Science Direct, Excerpta Medica Database (Embase) and Chinese Biomedical Literature Database (CBM) before May 2013. The association between the XRCC3 Thr241Met polymorphism and gliomas risk was conducted by odds ratios (ORs) and 95% confidence intervals (95% CIs). A total of nine case-control studies including 3,533 cases and 4,696 controls were eventually collected. Overall, we found that XRCC3 Thr241Met polymorphism was significantly associated with the risk of gliomas (T vs. C: OR=1.10, 95%CI=1.01-1.20, P=0.034; TT vs. CC: OR=1.30, 95%CI=1.03-1.65, P=0.027; TT vs. TC/CC: OR=1.29, 95%CI=1.01-1.64, P=0.039). In the subgroup analysis based on ethnicity, the significant association was found in Asian under four models (T vs. C: OR=1.17, 95%CI=1.07-1.28, P=0.00; TT vs. CC: OR=1.79, 95%CI=1.36-2.36, P=0.00; TT vs. TC/CC: OR=1.75, 95%CI=1.32-2.32, P=0.00; TT/TC vs. CC: OR=1.11,95% CI=1.02-1.20). This meta-analysis suggested that the XRCC3 Thr241Met polymorphism is a risk factor for gliomas, especially for Asians. Considering the limited sample size and ethnicities included in the meta-analysis, further large scale and well-designed studies are needed to confirm our results.