Comparison of Bypass Surgery with Drug-Eluting Stents in Diabetic Patients with Left Main Coronary Stenosis

Xiaoxiao Zhao,Yujie Zhou,Hui Song,Like Guan,Guanbin Zheng,Zhehu Jin,Dongmei Shi,Yuzi Li,Yonghe Guo,Guo-Ping Shi,Xian Wu Cheng 연세대학교의과대학 2011 Yonsei medical journal Vol.52 No.6

Purpose: Several studies have compared the effects of coronary stenting and coronary-artery bypass grafting (CABG) on left main coronary artery (LMCA) disease. However, there are limited data on the long-term outcomes of these two interventions in diabetic patients. Materials and Methods: We evaluated 56 patients with LMCA stenosis who underwent drug-eluting stent (DES) implantation and 116 patients who underwent CABG in a single hospital in China between January 2004 and December 2006. We compared long-term major adverse cardiac events (death; a “serious outcome” composite of death, myocardial infarction, or stroke; and target-vessel revascularization). Results: In-hospital (30-day) mortality was 0% for the DES group and 3.4% for the CABG group (p=0.31). There was no difference between the two groups in terms of risk of death [hazard ratio for stenting group, 0.49; 95% confidence interval (CI), 0.13-1.63; p=0.55] or risk of serious outcome (hazard ratio for DES group, 1.11; 95% CI, 0.39-1.45; p=0.47). The target-vessel revascularization rate was higher in the DES group than in the CABG group (hazard ratio, 3.67; 95% CI, 1.24-11.06; p=0.018). Conclusion: In this cohort of diabetic patients with LMCA stenosis, there was no difference in composite endpoints between patients receiving DESs and those undergoing CABG. However, stenting was associated with higher rates of target-vessel revascularization than CABG. DES implantation in diabetic patients with LMCA disease was found to be at least as safe as CABG.

Two-dimensional frictionless large deformation contact problems using isogeometric analysis and Nitsche’s method

Zhao Gang,Zhang Ran,Wang Wei,Du Xiaoxiao 한국CDE학회 2022 Journal of computational design and engineering Vol.9 No.1

The simulation of large deformation contact problems has been a tough subject due to the existence of multiple nonlinearities, including geometric nonlinearity and contact interface nonlinearity. In this paper, we develop a novel method to compute the large deformation of 2D frictionless contact by employing Nitsche-based isogeometric analysis. The enforcement of contact constraints as one of the main issues in contact simulation is implemented by using Nitsche’s method, and the node-to-segment scheme is applied to the contact interface discretization. We detailedly derive the discrete formulations for 2D large deformation frictionless contact where NURBS is used for geometrical modeling and the Neo-Hookean hyperelastic materials are applied to describe the deformation of the model. The collocation method with Greville points is employed to integrate the contact interface and the classical Legendre–Gauss quadrature rule is used for contact bodies’ integration. The Lagrange multiplier method and penalty method are also implemented for comparison with Nitsche’s method. Several examples are investigated, and the obtained results are compared with that from commercial software ABAQUS to verify the effectiveness and accuracy of the Nitsche-based isogeometric analysis.

Synthesis of Hβ (core)/SAPO-11 (shell) Composite Molecular Sieve and its Catalytic Performances in the Methylation of Naphthalene with Methanol

Xiaoxiao Wang,Shaoqing Guo,Liangfu Zhao 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.12

Hβ (core)/SAPO-11 (shell) composite molecular sieve was synthesized by the hydrothermal method in order to combine the advantages of Hβ and SAPO-11 for the methylation of naphthalene with methanol. For comparison, the mechanical mixture was prepared through the blending of Hβ and SAPO-11. The physicochemical properties of Hβ, SAPO-11, the composite and the mechanical mixture were characterized by various characterization methods. The characterization results indicated that Hβ/SAPO-11 composite molecular sieve exhibited a core-shell structure, with the Hβ phase as the core and the SAPO-11 phase as the shell. The pore diameter of the composite was between that of Hβ and SAPO-11. The composite had fewer acid sites than Hβ and mechanical mixture while more acid sites than SAPO-11. The experimental results indicated that the composite exhibited high catalytic performances for the methylation of naphthalene with methanol.

Features Fusion with Adaptive Weights for Pedestrian Classification

Junbo Zhao,Shuoshuo Chen,Weizi Liu,Xiaoxiao Chen 제어로봇시스템학회 2013 제어로봇시스템학회 국제학술대회 논문집 Vol.2013 No.10

In this paper, we study the problem of pedestrian classification, which could lead to an improvement of performance of the Pedestrian Detection Systems. Since the traditional approaches merely focus on the recognition of pedestrian, the device would keep alerting the drivers even if the pedestrians are walking on a safe track. We attempt to classify pedestrians in order to make those devices, equipped in the cars, more intelligent and pragmatic. We propose a method to extract features including HOGs (Histogram of Oriented Gradient), LTPs (Local Ternary Pattern), Color Names and to fuse them efficiently. The three features are weighted fused depending on the size of patches as well as each patch’s gradient value which is computed via a 3<SUP>*</SUP>3 Sobel operator. Afterwards we will train a random forest with 50 discriminative decision trees, using the fused features. Our method is tested on the images of humans from INRIA dataset. The experimental results show that our method of features fusion, with adaptive weights assigned to the different features, yields a significant gain of 12.9% in mean AP (Average Precision) over the simple features concatenation framework. Accordingly, our method is practicable for classifying pedestrians.

Analysis of Security Policy in Practical Internet Coordinates

Xiaohan Zhao,Xiaoxiao Song,Xiao Wang,Yang Chen,Beixing Deng,Xing Li 보안공학연구지원센터 2009 International Journal of Security and Its Applicat Vol.3 No.1

Network Coordinate (NC) System is an effective mechanism to predict network delay with limited measure overhead. As one of the representative NC systems, Practical Internet Coordinates (PIC) has proposed a security policy based on triangle inequality to defend malicious nodes in the system. However, there is a natural phenomena that nodes may violate triangle inequality in Internet. Thus, the performance of PIC security policy is worthy to be well researched under different attacks. In this paper, we analyze the security policy in PIC in three real network delay data sets and compare PIC with security to without security under four typical attacks. The experimental results in this paper demonstrate that PIC is vulnerable to attacks while more TIVs will cause higher relative error of PIC. Moreover, under attacks by more than 40% malicious nodes, the performance of PIC with security policy could barely be better than PIC without security. Even Colluding Isolate attack will result in worse performance in PIC having security policy.

Synthesis of Hβ (core)/SAPO-11 (shell) Composite Molecular Sieve and its Catalytic Performances in the Methylation of Naphthalene with Methanol

Wang, Xiaoxiao,Guo, Shaoqing,Zhao, Liangfu Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.12

$H{\beta}$ (core)/SAPO-11 (shell) composite molecular sieve was synthesized by the hydrothermal method in order to combine the advantages of $H{\beta}$ and SAPO-11 for the methylation of naphthalene with methanol. For comparison, the mechanical mixture was prepared through the blending of $H{\beta}$ and SAPO-11. The physicochemical properties of $H{\beta}$, SAPO-11, the composite and the mechanical mixture were characterized by various characterization methods. The characterization results indicated that $H{\beta}$/SAPO-11 composite molecular sieve exhibited a core-shell structure, with the $H{\beta}$ phase as the core and the SAPO-11 phase as the shell. The pore diameter of the composite was between that of $H{\beta}$ and SAPO-11. The composite had fewer acid sites than $H{\beta}$ and mechanical mixture while more acid sites than SAPO-11. The experimental results indicated that the composite exhibited high catalytic performances for the methylation of naphthalene with methanol.

Facile Fabrication of MCo2S4(M = Mn, Ni) Nanotube Arrays for High-Performance Supercapacitors

Peng Li,Xiaoxiao Ma,Fei Liu,Junhua Tan,Yanliang Zhao,Liyong Wang,Kaijin Zhu 대한금속·재료학회 2019 ELECTRONIC MATERIALS LETTERS Vol.15 No.4

MCo2S4(M = Mn, Ni) nanomaterials are attracting considerable attention because of their unique nanostructure, good redoxproperties, excellent theoretical capacitance, low cost and easy preparation. Herein, MCo2S4(M = Mn, Ni) nanotube arrayshave been fabricated by a one-pot hydrothermal method and could be used as conductive additive and binder-free electrodesfor supercapacitors. The results show that the specific capacitance of MCo2S4(M = Mn or Ni) nanotube arrays could reachas high as 2667 and 1623 F/g at the current density of 10 A/g, respectively, indicating high rate performance. Furthermore,the MnCo2S4nanotube arrays exhibited excellent cycling stability (68% of initial specific capacitance after 1800 cycles). These excellent electrochemical properties benefit from the synergistic effects of unique tubular microstructure and highconductivity of the samples.

Meta-analysis of the effect of the overexpression of aquaporin family genes on the drought stress response

Ren Jianhong,Yang Xiaoxiao,Ma Chunying,Wang Yuling,Zhao Juan,Kang Le 한국식물생명공학회 2021 Plant biotechnology reports Vol.15 No.2

Aquaporin (AQP) plays an essential role in water uptake and transport in plants, especially in the response to drought stress, which suggests the use of AQP expression to regulate plant water-use efciency. The overexpression of various AQP genes in a variety of plants has been reported, but inconsistencies in the experimental variables (such as stress type, gene donor, and recipient genus) and physiological parameters used to evaluate transgenic plants have made it difcult to elucidate the complex mechanisms by which AQPs afect drought tolerance. In this study, we performed a meta-analysis to categorize the responses of physiological parameters involved in drought tolerance in AQP-overexpressing plants and to evaluate the experimental variables that afect transgenic plant performance. The results of various studies indicated that two primary physiological processes (osmotic adjustment and alleviation of oxidative damage) were signifcantly afected by AQP overexpression. Among the examined experimental variables, treatment media (soil), stress type (no watering), stress duration (long-term), recipient genus (Nicotiana), donor species (Musaceae), and gene family (PIP2) had positive impacts on drought tolerance in transgenic plants. These fndings may help to guide future studies investigating the function of AQPs in the response of plants to water defcit stress.

The catalytic performance of methylation of naphthalene with methanol over SAPO-11 zeolites synthesized with different Si content

Shaoqing Guo,Liangfu Zhao,Xiaoxiao Wang,Fang Guo,Xianxian Wei,Zhenmin Liu,Wei Zhang 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.7

A series of SAPO-11 zeolites with different Si contents were prepared by hydrothermally synthesized method. They were characterized by ICP, XRD, SEM, FT-IR, N2 adsorption-desorption, NH3-TPD and 29Si MAS NMR, and evaluated by the methylation of naphthalene with methanol to 2,6-dimethylnaphthalene (2,6-DMN). According to XRD and SEM results, the crystallinity of SAPO-11 sample increased with increase of the Si content until the SiO2/Al2O3 ratio was up to 0.2. However, a reduction in the crystallinity was observed with further increase of the Si content of the synthesis. N2 adsorption-desorption results showed that all the samples possessed micropores and secondary mesopores. SAPO-11 sample with SiO2/Al2O3 ratio of 0.2 exhibited the largest secondary mesopores size distributions. NH3-TPD and 29Si MAS NMR showed that the Si content was incorporated into the framework affecting not only the acid sites but also the acid strength of SAPO-11. SAPO-11 with SiO2/Al2O3 ratio of 0.2 presented the high catalytic performances for the methylation of naphthalene, which was mainly attributed to the amount of secondary mesopores in the SAPO-11 zeolite.

Singularity analysis and workspace optimization of a novel symmetrical 4-limb 5-DOF hybrid robot

Xin Tian,Tieshi Zhao,XiaoXiao Peng,Erwei Li 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.5

Considering the complex structure and large size of multiple axes rotary spindle heads and the small workspace of parallel modules, a 5-degree of freedom (DOF) hybrid robot is proposed, which is a symmetrical 4-limb parallel module in series with a single axis rotary spindle head. Screw theory was used to analyze the mobility and kinematics of the hybrid mechanism. The singularity of the symmetrical 4-limb parallel module was studied, and the analysis results were verified by the Grassmann linear geometry principle. According to the singularity analysis results, the kinematic pairs’ positions of the robot were determined, so the hybrid robot model was constructed. Considering the workspace volume, and optimizing the Latin hypercube sample algorithm, a combinatorial numerical optimization algorithm is proposed to optimize dimension parameters of this hybrid robot, which combines non-linear programming by quadratic Lagrangian (NLPQL) algorithm with the optimized Latin hypercube sampling (Opt LHS) algorithm. Through this optimization algorithm, the workspace volume of the robot is increased by 1.93 times. The research method in this paper is also suitable for the analysis and optimization of other hybrid robots.