• Title/Summary/Keyword: Stress Parameters

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Clinical Significance of Soluble Major Histocompatibility Complex Class I Chain-related A in Renal Cell Carcinoma Patients

  • Qiu, Yu;Zhao, Ya-Kun;Yuan, Gang-Jun;Zhu, Qing-Guo
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.5651-5655
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    • 2013
  • Objective: Major histocompatibility complex class I chain-related A (MICA) is a stress-inducible glycoprotein that can be shed as a soluble protein. This study was conducted to determine the expression of MICA in renal cell carcinoma (RCC) and examine the clinical relevance of soluble MICA (sMICA) in this disease. Methods: Immunohistochemistry and real-time PCR analyses were performed to assess the expression of MICA in 48 pairs of RCC and adjacent normal renal tissues. Serum levels of sMICA were measured in 48 RCC patients, 12 patients with benign renal tumors, and 20 healthy individuals. The correlations between sMICA levels and clinicopathological parameters were analyzed and the diagnostic performance of sMICA in RCC was evaluated. Results: RCCs exhibited elevated expression of MICA compared to adjacent normal tissues. Serum concentrations of sMICA were significantly greater in RCC patients ($348.5{\pm}32.5pg/ml$) than those with benign disease ($289.3{\pm}30.4pg/ml$) and healthy controls ($168.4{\pm}43.2pg/ml$) and significantly correlated with advanced tumor stage, lymph node metastasis, distant metastasis, vascular invasion, and higher histological grade. Using a cut-off point of 250 pg/ml, sMICA demonstrated a specificity and sensitivity of 63.2% and 75.6%, respectively, in distinguishing between RCC and benign renal tumors. Conclusion: MICA expression is upregulated in RCC and increased serum sMICA levels predict aggressive tumor behavior. However, the applicability of sMICA alone is limited in distinguishing RCC from benign renal tumors.

Features of Malignancy Prevalence among Children in the Aral Sea Region

  • Mamyrbayev, Arstan;Dyussembayeva, Nailya;Ibrayeva, Lyazzat;Satenova, Zhanna;Tulyayeva, Anara;Kireyeva, Nurgul;Zholmukhamedova, Dinara;Rybalkina, Dina;Yeleuov, Galymzhan;Yeleuov, Almasbek
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.12
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    • pp.5217-5221
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    • 2016
  • Objective: A study of primary cancer morbidity among children and subsequent calculation of average annual incidence were carried out for boys and girls, and young men and women in Kazakhstan. Methods: The investigated population lived in three areas of the Aral Sea region: designated catastrophe (Aral, Kazalt, Shalkar regions), crisis (Zhalagash, Karmakshy, Shiely regions), pre-crisis (Irgiz, Arys, Ulytau regions). Zhanaarka region of Karaganda oblast was applied as a control. Parameters were retrospective analyzed for the 10 years from 2004 to 2013. Result: The results indicate that indices of children cancer morbidity were slightly higher in the Aral Sea region than in the control district, but they were comparable with similar data from studies in other regions. In all areas of the Aral Sea region, except for Ulytau, primary cancer morbidity exceeded the control level by 1.3-2.7 times (4.7%000). Hematological malignancies, including solid tumors - tumors of musculoskeletal system and skin, digestive system, brain and central nervous system predominated. Stress levels in zones of the Aral Sea region were slightly higher in the crisis zone than in the catastrophe zone that can be explained by the phenomenon of wave-like dynamics of disease growth risk. Gender differences in characteristics of malignancy formation were not more pronounced in the studied region. Conclusion: Indices of children cancer are slightly higher in the Aral Sea region than in the control area of Kazakhstan, but they are comparable to results for other regions.

A Parametric Study on Tensile Stress of a Hybrid Floating Structure System (매개변수 연구를 통한 하이브리드형 부유식 구조물의 인장응력 발생 분석)

  • Zi, Goangseup;Lee, Seung-Jung;Kwak, Yeon-Min;Jeong, Youn
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.5B
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    • pp.313-320
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    • 2012
  • A hybrid floating structure system combined with pontoon and semi-submersible type modules is proposed. This new system can reduce tensile forces of bottom slabs which could cause fatal damage of concrete floating structures. We performed a parametric study on the dimensions of this new system and investigate the sensitivity of the parameters to the behavior. In order to investigate various cases efficiently, we developed a simple two-step static analysis method for the fluid-structure interaction. An optimum system is derived from the investigation of the analysis results, weights and drafts of the hybrid structure. This study shows that introducing this new system to concrete floating structures is an effective way to reduce the tensile force of the bottm slab of such a floating structure. Also, it was found that when the length of the semi-submersible module is about 15%, the behavior would be optimal in the considered case.

Prediction of Spring Rate and Initial Failure Load due to Material Properties of Composite Leaf Spring (복합재 판스프링의 재료특성에 따른 스프링 강성변화와 초기 파단하중 예측)

  • Oh, Sung Ha;Choi, Bok Lok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.12
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    • pp.1345-1350
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    • 2014
  • This paper presented analysis methods for adapting E-glass fiber/epoxy composite (GFRP) materials to an automotive leaf spring. It focused on the static behaviors of the leaf spring due to the material composition and its fiber orientation. The material properties of the GFRP composite were directly measured based on the ASTM standard test. A reverse implementation was performed to obtain the complete set of in-situ fiber and matrix properties from the ply test results. Next, the spring rates of the composite leaf spring were examined according to the variation of material parameters such as the fiber angles and resin contents of the composite material. Finally, progressive failure analysis was conducted to identify the initial failure load by means of an elastic stress analysis and specific damage criteria. As a result, it was found that damage first occurred along the edge of the leaf spring owing to the shear stresses.

Low velocity impact response and dynamic stresses of thick high order laminated composite truncated sandwich conical shell based on a new TDOF spring-mass-damper model considering structural damping

  • Azizi, A.;Khalili, S.M.R.;Fard, K. Malekzadeh
    • Steel and Composite Structures
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    • v.26 no.6
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    • pp.771-791
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    • 2018
  • This paper deals with the low velocity impact response and dynamic stresses of composite sandwich truncated conical shells (STCS) with compressible or incompressible core. Impacts are assumed to occur normally over the top face-sheet and the interaction between the impactor and the structure is simulated using a new equivalent three-degree-of-freedom (TDOF) spring-mass-damper (SMD) model. The displacement fields of core and face sheets are considered by higher order and first order shear deformation theory (FSDT), respectively. Considering continuity boundary conditions between the layers, the motion equations are derived based on Hamilton's principal incorporating the curvature, in-plane stress of the core and the structural damping effects based on Kelvin-Voigt model. In order to obtain the contact force, the displacement histories and the dynamic stresses, the differential quadrature method (DQM) is used. The effects of different parameters such as number of the layers of the face sheets, boundary conditions, semi vertex angle of the cone, impact velocity of impactor, trapezoidal shape and in-plane stresses of the core are examined on the low velocity impact response of STCS. Comparison of the present results with those reported by other researchers, confirms the accuracy of the present method. Numerical results show that increasing the impact velocity of the impactor yields to increases in the maximum contact force and deflection, while the contact duration is decreased. In addition, the normal stresses induced in top layer are higher than bottom layer since the top layer is subjected to impact load. Furthermore, with considering structural damping, the contact force and dynamic deflection decrees.

Investigation of influence of homogenization models on stability and dynamic of FGM plates on elastic foundations

  • Mehala, Tewfik;Belabed, Zakaria;Tounsi, Abdelouahed;Beg, O. Anwar
    • Geomechanics and Engineering
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    • v.16 no.3
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    • pp.257-271
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    • 2018
  • In this paper, the effect of the homogenization models on buckling and free vibration is presented for simply supported functionally graded plates (FGM) resting on elastic foundation. The majority of investigations developed in the last decade, explored the Voigt homogenization model to predict the effective proprieties of functionally graded materials at the macroscopic-scale for FGM mechanical behavior. For this reason, various models have been used to derive the effective proprieties of FGMs and simulate thereby their effects on the buckling and free vibration of FGM plates based on comparative studies that may differ in terms of several parameters. The refined plate theory, as used in this paper, is based on dividing the transverse displacement into both bending and shear components. This leads to a reduction in the number of unknowns and governing equations. Furthermore the present formulation utilizes a sinusoidal variation of displacement field across the thickness, and satisfies the stress-free boundary conditions on the upper and lower surfaces of the plate without requiring any shear correction factor. Equations of motion are derived from Hamilton's principle. Analytical solutions for the buckling and free vibration analysis are obtained for simply supported plates. The obtained results are compared with those predicted by other plate theories. This study shows the sensitivity of the obtained results to different homogenization models and that the results generated may vary considerably from one theory to another. Comprehensive visualization of results is provided. The analysis is relevant to aerospace, nuclear, civil and other structures.

Compressive performance of RAC filled GFRP tube-profile steel composite columns under axial loads

  • Ma, Hui;Bai, Hengyu;Zhao, Yanli;Liu, Yunhe;Zhang, Peng
    • Advances in concrete construction
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    • v.8 no.4
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    • pp.335-349
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    • 2019
  • To investigate the axial compressive performance of the recycled aggregate concrete (RAC) filled glass fiber reinforced polymer (GFRP) tube and profile steel composite columns, static loading tests were carried out on 18 specimens under axial loads in this study, including 7 RAC filled GFRP tube columns and 11 RAC filled GFRP tube-profile steel composite columns. The design parameters include recycled coarse aggregate (RCA) replacement percentage, profile steel ratio, slenderness ratio and RAC strength. The failure process, failure modes, axial stress-strain curves, strain development and axial bearing capacity of all specimens were mainly analyzed in detail. The experimental results show that the GFRP tube had strong restraint ability to RAC material and the profile steel could improve the axial compressive performance of the columns. The failure modes of the columns can be summarized as follow: the profile steel in the composite columns yielded first, then the internal RAC material was crushed, and finally the fiberglass of the external GFRP tube was seriously torn, resulting in the final failure of columns. The axial bearing capacity of the columns decreased with the increase of RCA replacement percentage and the maximum decreasing amplitude was 11.10%. In addition, the slenderness ratio had an adverse effect on the axial bearing capacity of the columns. However, the strength of the RAC material could effectively improve the axial bearing capacity of the columns, but their deformability decreased. In addition, the increasing profile steel ratio contributed to the axial compressive capacity of the composite columns. Based on the above analysis, a formula for calculating the bearing capacity of composite columns under axial compression load is proposed, and the adverse effects of slenderness ratio and RCA replacement percentage are considered.

The expanded LE Morgenstern-Price method for slope stability analysis based on a force-displacement coupled mode

  • Deng, Dong-ping;Lu, Kuan;Wen, Sha-sha;Li, Liang
    • Geomechanics and Engineering
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    • v.23 no.4
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    • pp.313-325
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    • 2020
  • Slope displacement and factor of safety (FOS) of a slope are two aspects that reflect the stability of a slope. However, the traditional limit equilibrium (LE) methods only give the result of the slope FOS and cannot be used to solve for the slope displacement. Therefore, developing a LE method to obtain the results of the slope FOS and slope displacement has significance for engineering applications. Based on a force-displacement coupled mode, this work expands the LE Morgenstern-Price (M-P) method. Except for the mechanical equilibrium conditions of a sliding body adopted in the traditional M-P method, the present method introduces a nonlinear model of the shear stress and shear displacement. Moreover, the energy equation satisfied by a sliding body under a small slope displacement is also applied. Therefore, the double solutions of the slope FOS and horizontal slope displacement are established. Furthermore, the flow chart for the expanded LE M-P method is given. By comparisons and analyses of slope examples, the present method has close results with previous research and numerical simulation methods, thus verifying the feasibility of the present method. Thereafter, from the parametric analysis, the following conclusions are obtained: (1) the shear displacement parameters of the soil affect the horizontal slope displacement but have little effect on the slope FOS; and (2) the curves of the horizontal slope displacement vs. the minimum slope FOS could be fitted by a hyperbolic model, which would be beneficial to obtain the horizontal slope displacement for the slope in the critical state.

The therapeutic effects of WSY-0702 on benign prostatic hyperplasia in RWPE-1

  • Oh, Hyun-A;Kwon, Eun Bi;Hwang, Yun Gyeong;Park, Soon Eung;Mok, Ji Ye;Hwang, Sung Yeoun
    • CELLMED
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    • v.7 no.2
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    • pp.8.1-8.7
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    • 2017
  • Benign prostatic hyperplasia (BPH) is one of the major diseases of the urinary system in older men. WSY-0702 is the extracted from the traditional medicinal plant; Seoritae, and it has effects of anti-obesity, chronic cervical pain, and anti-oxidant. The present study aimed to investigate the therapeutic potential of WSY-0702 in the prevention and treatment of BPH. Several parameters including inflammatory mediators, hormones, and oxidative stress (OS) have been considered to play a role in the development of BPH. Prostate tissue damage and OS may lead to compensatory cellular proliferation with resulting hyperplastic growth. An in vitro study showed that proliferation inhibited the human prostate epithelial cell line RWPE-1 in a dose-dependent manner. In cell line, the cell cycle at the G2/M and G0/G1 phase and downregulated the expression of CyclineB1 (CCNB1) and CyclineD1 (CCND1). In addition, we measured the $H_2O_2$-induced OS damage using RWPE-1 cells. We examined the relative expression of protein involved in the regulation of prostate apoptosis: transforming growth factor (TGF)-${\beta}$, a negative growth factor able to induced prostate apoptosis under physiological conditions. These results suggest that WSY-0702 that can inhibit the growth of prostate epithelial cell by a mechanism that may involve arresting the cell cycle and downregulating CCNB1 and CCND1 expression. In addition, WSY-0702 exposure resulted in significant protective effects in $H_2O_2$-stressed PWPE-1 cells by reduction in TGF-${\beta}$ levels.

Antioxidant Activity of Medicinal Plant Extracts Used as Folk Remedies by Diabetic Patients

  • Park, Min-Jung;Han, Ji-Sook
    • Preventive Nutrition and Food Science
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    • v.9 no.2
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    • pp.167-173
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    • 2004
  • The aim of this study was to investigate the antioxidant effect of medicinal plants used by diabetic patients. Fourteen medicinal plants were selected and antioxidant activity such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, inhibition effect of linoleic acid autoxidation and low density lipoprotein (LDL) oxidation, thiobarbituric acid (TBA) value were measured. The Cornus officinalis had DPPH radical scavenging activity of 84.79%, which was higher than the 78.79% for $\alpha$-tocopherol. Rosa rugosa Thunberg, Pueraria thundergiana Bentham, Artemisia princeps var. orientalis and Sasamorpha purpurascens Nakai also had high values. Extracts with higher DPPH radical scavenging activities had higher total phenol concentrations, and positive correlations between these parameters were found. Inhibitory activities of linoleic acid autoxidation, LDL oxidation and TBA value, used as indices of oxidative stress, were observed in most of the selected medicinal plants. The highest inhibitory activity for TBA value was observed in the extract of Pueraria thundergiana Bentham. Rosa rugosa Thunberg (75.50 %), Sasamorpha purpurascens Nakai (74.00 %), and Cornus officinalis (73.00 %) all had high antioxidant activity against linoleic acid autoxidation, similar to that of $\alpha$-tocopherol. The same 3 plants also had high in inhibitory activity against LDL oxidation. Therefore, we demonstrated that medicinal plants used as folk remedy by diabetic patients had antioxidant activity. Especially, Rosa rugosa Thunberg, Cornus officinalis, Pueraria thundergiana Bentham, Arlemisia princeps var. orientalis, and Sasamorpha purpurascens Nakai had high phenol concentrations which resulted in high values for DPPH radical scavenging. These same plants exhibited high values for inhibitory activities for TBA value, linoleic acid autoxidation and LDL oxidation, indices associated with lipid peroxidation.