LSKL, a Peptide Antagonist of Thrombospondin-1, Attenuates Renal Interstitial Fibrosis in Rats with Unilateral Ureteral Obstruction

Xi-sheng Xie,Fei-yan Li,Heng-chuan Liu,Yao Deng,Zi Li,Jun-ming Fan 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.2

The effects of LSKL, the peptide antagonist of thrombospondin-1 (TSP-1), on renal interstitial fibrosis in rats subjected to unilateral ureteral obstruction (UUO) were investigated. Rats were divided randomly into three groups (n = 20 each): UUO group, sham-operation group and UUO plus LSKL treatment group. Collagen deposition was studied using histopathology and reverse transcription polymerase chain reaction analysis (RT-PCR). TSP-1, transforming growth factor beta 1 (TGF-β1), phosphorylated Smad2 (pSsmad2) and α-smooth muscle actin (α-SMA) in the kidney were measured using immunocytochemistry, western blotting analysis, RT-PCR and enzyme-linked immunosorbent assay. Biochemical analyses in the serum and urine were made. Histopathology showed severe tubular dilatation and atrophy, interstitial inflammation and collagen accumulation after surgery and LSKL significantly inhibited interstitial fibrosis including tubular injury as well as collagen deposition. The protein and mRNA levels of TSP-1 increased notably at different time point and significantly decreased in the presence of LSKL. The expression of TGF-β1 and pSmad2 were upregulated in the obstructed kidney and substantially suppressed by LSKL treatment. Myofibroblast accumulation could be alleviated after administration of LSKL. Biochemical parameters did not show differences among the three groups. As TSP-1 is the major activator of TGF-β1, we demonstrate that LSKL can attenuate renal interstitial fibrosis in vivo by preventing TSP-1-mediated TGF-β1 activation.

Process of Equiaxed Grains of RE-Al Alloy under Slope Vibration

Xie Shi-kun,Yi Rong-xi,Pan Xiao-liang,Zheng Xiao-qiu,Guo Xiu-yan 한국소성가공학회 2010 기타자료 Vol.2010 No.6

A new technique using slope vibration casting process during heating and isothermal holding period to prepare Al-7Si-2RE alloy has been studied. The small, near-spherical and non-dendritic microstructure with the semi-solid processing requirements has been obtained. Experiments show that the cooling method, pouring process and the convection of melt caused by slope vibration had significant effects on the formation of near-spherical primary gains. The water-cooled copper mold casting with slope vibration at the temperature near liquidus can obtain Al-7Si-2RE alloy with small homogeneous equiaxed grains, the average grain diameter is 48.3μm, and the average grain roundness is 1.92.

Expression of ERCC1, MSH2 and PARP1 in Non-small Cell Lung Cancer and Prognostic Value in Patients Treated with Platinum-based Chemotherapy

Xie, Ke-Jie,He, Hong-Er,Sun, Ai-Jing,Liu, Xi-Bo,Sun, Li-Ping,Dong, Xue-Jun Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.6

Purpose: To evaluate the prognostic value of the expression of excision repair cross-complementation group l (ERCC1), MutS protein homolog 2 (MSH2) and poly ADP-ribose polymerase 1 (PARP1) in non-small-cell lung cancer patients receiving platinum-based postoperative adjuvant chemotherapy. Methods: Immunohistochemistry was applied to detect the expression of ERCC1, MSH2 and PARP1 in 111 cases of non-small cell lung cancer paraffin embedded surgical specimens. Through og-rank survival analysis, we evaluated the prognostic value of the ERCC1, MSH2, PARP1 and the related clinicopathological factors. COX regression analysis was used to determine whether ERCC1, MSH2 and PARP1 were independent prognostic factors. Results: In the enrolled 111 non-small cell lung cancer patients, the positive expression rate of ERCC1, MSH2 and RARP1 was 33.3%, 36.9% and 55.9%, respectively. ERCC1 (P<0.001) and PARP1 (P=0.033) were found to be correlated with the survival time while there was no correlation for MSH2 (P=0.298). Patients with both ERCC1 and PARP1 negative cancer had significantly longer survival time than those with ERCC1 (P=0.042) or PARP1 (P=0.027) positive alone. Similalry, the survival time of patients with both ERCC1 and PARP1 positive cancer was shorter than those with ERCC1 (P=0.048) or PARP1 (P=0.01) positive alone. Conclusion: Patients with ERCC1 or PARP1 negative non-small cell lung cancer appear to benefit from platinum-based postoperative adjuvant chemotherapy.

Investigation of the Mechanism of Period-doubling Bifurcation in Voltage Mode Controlled Buck-Boost Converter

Xie, Ling-Ling,Gong, Ren-Xi,Zhuo, Hao-Ze,Wei, Jiong-Quan The Korean Institute of Electrical Engineers 2011 Journal of Electrical Engineering & Technology Vol.6 No.4

An investigation of the mechanism of period-doubling bifurcation in a voltage mode controlled buck-boost converter operating in discontinuous conduction mode is conducted from the viewpoint of nonlinear dynamical systems. The discrete iterative model describing the dynamics of the close-loop is derived. Period-doubling bifurcation occurs at certain values of the feedback factor. Results from numerical simulations and experiments are provided to verify the evolution of perioddoubling bifurcation, and the results are consistent with the theoretical analysis. These results show that the buck-boost converters exhibit a wide range of nonlinear behavior, and the system exhibits a typical period-doubling bifurcation route to chaos under particular operating conditions.

Emodin-Provoked Oxidative Stress Induces Apoptosis in Human Colon Cancer HCT116 Cells through a p53-Mitochondrial Apoptotic Pathway

Xie, Mei-Juan,Ma, Yi-Hua,Miao, Lin,Wang, Yan,Wang, Hai-Zhen,Xing, Ying-Ying,Xi, Tao,Lu, Yuan-Yuan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.13

Emodin, a natural anthraquinone isolated from the traditional Chinese medicine Radix rhizoma Rhei, can induce apoptosis in many kinds of cancer cells. This study demonstrated that emodin induces apoptosis in human colon cancer HCT116 cells by provoking oxidative stress, which subsequently triggers a p53-mitochondrial apoptotic pathway. Emodin induced mitochondrial transmembrane potential loss, increase in Bax and decrease in Bcl-2 expression and mitochondrial translocation and release of cytochrome c to cytosol in HCT116 cells. In response to emodin-treatment, ROS increased rapidly, and subsequently p53 was overexpressed. Pretreatment with the antioxidant NAC diminished apoptosis and p53 overexpression induced by emodin. Transfecting p53 siRNA also attenuated apoptosis induced by emodin, Bax expression and mitochondrial translocation being reduced compared to treatment with emodin alone. Taken together, these results indicate that ROS is a trigger of emodin-induced apoptosis in HCT116 cells, and p53 expression increases under oxidative stress, leading to Bax-mediated mitochondrial apoptosis.

The impact of port efficiency as an infrastructure for international trade on the city’s total factor productivity(TFP) - Evidence from Chinese ports

Xi-Na Ji(기석나),Xiao-Xuan Xie(해소훤),Kyoung-Suk Choi(최경숙) 한국무역학회 2023 貿易學會誌 Vol.48 No.6

본 연구는 2010년부터 2017년까지 양쯔강 연안 주요 14개 내륙 항만의 패널 데이터를 활용하여, 3단계 DEA 방법을 통해 상대적 효율성을 분석하고, 도출된 항만효율성이 항만배후도시의 총요소생산성(TFP)에 미치는 영향을 분석하고자 하였다. 분석을 위해 Ordinary Least Squares (FMOLS), Dynamic Ordinary Least Squares (DOLS), and Pooled Mean Group (PMG) 회귀분석 방법을 활용하였다. 분석 결과, 항만효율성의 개선은 배후지역의 TFP를 장기적 관점에서 유의하게 증진시키는 것으로 나타났으며, 배후도시 외에 항만 인근 지역들로의 파급효과(spillover effect)도 확인되었다. This study used panel data from 14 major inland ports along the Yangtze River from 2010 to 2017 to analyze relative port efficiency through a three-stage DEA and determined whether the derived port efficiency is related to the total factor productivity (TFP) of port hinterland cities. For analysis, Ordinary Least Squares (FMOLS), Dynamic Ordinary Least Squares (DOLS), and Pooled Mean Group (PMG) regression analysis methods were used. As a result of the analysis, improvement in port efficiency was found to significantly increase the TFP of the hinterland area from a long-run perspective, and a spillover effect to areas near the port in addition to the hinterland city was also confirmed.

Enhancement of 1,3-Dihydroxyacetone Production from Gluconobacter oxydans by Combined Mutagenesis^s

( Xi Lin ),( Sha Liu ),( Guangrong Xie ),( Jing Chen ),( Penghua Li ),( Jianhua Chen ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.11

Wild strain L-6 was subjected to combined mutagenesis, including UV irradiation, atmospheric and room temperature plasma, and ion beam implantation, to increase the yield of 1,3-dihydroxyacetone (DHA). With application of a high-throughput screening method, mutant Gluconobacter oxydans I-2-239 with a DHA productivity of 103.5 g/l in flask-shake fermentation was finally obtained with the starting glycerol concentration of 120 g/l, which was 115.7% higher than the wild strain. The cultivation time also decreased from 54 h to 36 h. Compared with the wild strain, a dramatic increase in enzyme activity was observed for the mutant strain, although the increase in biomass was limited. DNA and amino acid sequence alignment revealed 11 nucleotide substitutions and 10 amino acid substitutions between the sldAB of strains L-6 and I-2-239. Simulation of the 3-D structure and prediction of active site residues and PQQ binding site residues suggested that these mutations were mainly related to PQQ binding, which was speculated to be favorable for the catalyzing capacity of glycerol dehydrogenase. RT-qPCR assay indicated that the transcription levels of sldA and sldB in the mutant strain were respectively 4.8-fold and 5.4-fold higher than that in the wild strain, suggesting another possible reason for the increased DHA productivity of the mutant strain.

alAn Intratracheal Challenge Murine Model of Asthma: Can Bronchial Inflammation Affect the Nose?

Jiaxing Xie,Yin Xi,Qingling Zhang,Guoqin Chen,Luo Wei,Kefang Lai,Nanshan Zhong 대한천식알레르기학회 2015 Allergy, Asthma & Immunology Research Vol.7 No.1

Purpose: Extensive data support the influence of the upper airway on lower airway inflammation and pathophysiology in allergic disease. However, few studies have focused on allergic inflammation in the nose after an isolated lower airway allergen challenge, a situation that can exist clinically when human subjects breathe primarily through the mouth, as occurs when nasally congested. This study used a mouse model to investigate whether upper airway inflammation and hyperresponsiveness were induced by an isolated lower airway allergen challenge. Methods: BALB/c mice were sensitized by systemic intraperitoneal injection of ovalbumin/saline and challenged with intratracheal ovalbumin/saline. Inflammation in the nose and lungs was assessed by cytology and histology of nasal tissues and bronchoalveolar lavage fluid (BALF), while nasal airway resistance and response were measured over 3 days post-challenge. Results: Intratracheal application of an allergen in anaesthetized mice resulted in exclusive deposition in the lower airway. Compared to control animals, ovalbumin -sensitized mice after challenge showed bronchial hyperreactivity and increased IL-5 in the serum BALF, as well as eosinophil infiltration in the lungs. However, nasal histology of the ovalbumin-sensitized mice showed no increase in eosinophil infiltration. The nasal lavage fluid revealed no increase in eosinophils or IL-5, and the nasal airway resistance did not increase after challenge either. Conclusions: In a mouse allergy model, exclusive allergen challenge of the lower airway can elicit a pulmonary and systemic allergic response, but does not induce upper airway inflammatory or physiological responses.

Capacity Analysis of an AF Relay Cooperative NOMA System Using MRC

( Xianbin Xie ),( Yan Bi ),( Xi Nie ) 한국인터넷정보학회 2020 KSII Transactions on Internet and Information Syst Vol.14 No.10

Non-orthogonal multiple access (NOMA) is widely studied in both academia and industry due to its high spectral efficiency over orthogonal multiple access (OMA). To effectively improve spectrum efficiency, an amplify-and-forward (AF) cooperative NOMA system is proposed as well as a novel detection scheme is proposed, in which we first perform successive interference cancellation (SIC) twice at U1 for the two signals received from two time slots to remove interference from symbol 2, then two new signals apply max ratio combining (MRC). In addition, a closed-form upper bound approximation for the ergodic capacity of our proposed system is derived. Monte-Carlo simulations and numerical analysis illustrate that our proposed system has better ergodic capacity performance than the conventional cooperative NOMA system with decode-forward (DF) relay, the conventional cooperative NOMA system with AF relay and the proposed AF cooperative NOMA system in [16]. In addition, we can see that ergodic capacity of all NOMA cooperative systems increase with the increase of transmit SNR. Finally, simulations display that power allocation coefficients have little effect on ergodic capacity of all NOMA cooperative systems. This is due to this fact that ergodic capacity of two symbols can be complementary with changing of power allocation coefficients.

Estimating the Probability Density Function of Remaining Useful Life for Wiener Degradation Process with Uncertain Parameters

Guo Xie,Xin Li,Xi Peng,Fucai Qian,Xinhong Hei 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.11

The effective prediction of remaining useful life is essential to realize system failure diagnosis and health management. The existing researches often assume that the degradation model is constant or the degradation process is measurable. The accurate degradation model, however, usually can not be established, and the parametric variation and measurement error of the degradation process are unavoidable, which makes it hard to obtain the exact value for predicting the remaining useful life. Regarding this problem, on basis of the concept of first failure time, a real-time probability density function is derived for the Wiener degradation process with the uncertainty of parameters, the stochasticity of degradation process and the randomness of measurement error. The main steps are as follows: firstly, the degradation model with three kinds of uncertainties is established, and then the stochastic degradation state and the parameters of the uncertainty model are estimated by fusion Kalman/UFIR filter; then, the analytical expression of the probability density function of remaining useful life is deduced. Finally, the correctness and effectiveness of the proposed method are verified by a group of comparison experiments and Monte Carlo simulations.