bluuebunny/crossref_metadata_2025 huggingface dataset:
Short-term peripheral nerve stimulation ameliorates axonal dysfunction after spinal cord injury
Authors: Lee Michael , Kiernan Matthew C. , Macefield Vaughan G. , Lee Bonne B. , Lin Cindy S.-Y.
Published: March 2015

There is accumulating evidence that peripheral motor axons deteriorate following spinal cord injury (SCI). Secondary axonal dysfunction can exacerbate muscle atrophy, contribute to peripheral neuropathies and neuropathic pain, and lead to further functional impairment. In an attempt to ameliorate the adverse downstream effects that developed following SCI, we investigated the effects of a short-term peripheral nerve stimulation (PNS) program on motor axonal excitability in 22 SCI patients. Axonal excitability studies were undertaken in the median and common peroneal nerves (CPN) bilaterally before and after a 6-wk unilateral PNS program. PNS was delivered percutaneously over the median nerve at the wrist and CPN around the fibular head, and the compound muscle action potential (CMAP) from the abductor pollicis brevis and tibialis anterior was recorded. Stimulus intensity was above motor threshold, and pulses (450 μs) were delivered at 100 Hz with a 2-s on/off cycle for 30 min 5 days/wk. SCI patients had consistently high thresholds with a reduced CMAP consistent with axonal loss; in some patients the peripheral nerves were completely inexcitable. Nerve excitability studies revealed profound changes in membrane potential, with a “fanned-in” appearance in threshold electrotonus, consistent with membrane depolarization, and significantly reduced superexcitability during the recovery cycle. These membrane dysfunctions were ameliorated after 6 wk of PNS, which produced a significant hyperpolarizing effect. The contralateral, nonstimulated nerves remained depolarized. Short-term PNS reversed axonal dysfunction following SCI, may provide an opportunity to prevent chronic changes in axonal and muscular function, and may improve rehabilitation outcomes.
An Analytical Model of Thermal Conductivity for Carbon/Carbon Composites with Pitch-Based Matrix
Authors: Feng Zhi-Hai , Zhi Jia-Yun , Fan Zhen , Sun Duo , Si Chao , Wang Xiao-Dong
Published: March 2015

The carbon/carbon (C/C) composites are composed of carbon fibers, carbon matrix, and pores and cracks, which have been successfully used in various aerospace applications. In this paper, nanoscale submodel is proposed to describe the thermal conductivity of the matrix based on its microscopic structure, and then the submodel is incorporated into a microscale model to analytically predict the equivalent thermal conductivities of the composites by equivalent circuit approach. The results predicted by the present model agree well with those from the experimental measurements. Based on the model, the effects of the composite porosity as well as the thickness and porosity of the interface phase on the thermal performance of five composites are studied. It is found that the thermal conductivities show decreasing trends in responding to an increase in each of the three parameters. The composite porosity has a significant effect on the thermal conductivities both parallel and transverse to the fiber axis, while the thickness and the porosity of the interface phase remarkably affect the thermal conductivity only transverse to the fiber axis.
A Mathematical Model for Temperature Induced Loosening due to Radial Expansion of Rectangle Thread Bolted Joints
Authors: Hou Shiyuan , Liao Ridong , Li Jishan
Published: March 2015

This paper proposed a mathematical model to investigate the radial expansion induced loosening of rectangle thread bolted joints that were subjected to cyclic temperature variation, which could cause slippage between contact pairs of engaged threads and bolt bearing. Firstly, integral equations were derived for the shear stress components caused by expansion difference, as well as the bearing and thread friction torque components, which depended on the temperature variation. Secondly, the relationship of displacement components was developed based on quasi-static hypotheses. Then, treating the rotation of bolt as plastic elongation, the bolt tension's evolution was obtained by using a one-dimensional bolted joint model. Numerical results showed that the temperature variation decreased the bearing and thread friction torque components, which could lead bolted joint to loosen. Finally, the effects of some associated factors on the progress were discussed.
Tool Steels in Die-Casting Utilization and Increased Mold Life
Authors: Naimi Sepanta , Hosseini Seyedeh Maryam
Published: March 2015

In die-casting molds, heat-checking is the typical failure mechanism. Optimizing the parameters that decrease this failure venture should be considered when designing and heat treating steels. The quality of die steels and their treatment continue to improve. This research investigated properties of the traditional materials 1.2343 and 1.2344 and the new steels (Dievar and TOOLOX 44) when applied to the die-casting mold specimens, after different experimental cycles. Also microstructures of the mentioned materials were analyzed by scanning electron microscopy (SEM) test. Chrome-molybdenum-silicon-vanadium steels have good hardening ability in oil and in air. Therefore, the hot-work steels have considerable toughness and plastic attributes through both regular and higher temperatures. So, it is a good traditional die-casting material. However, another special die steel, such as Dievar, is a particularly developed steel grade; its exclusivity profile is exceptional due to its chemical composition and the use of the latest production techniques. Dievar has good heat-checking and gross-cracking resistance as a result of both high toughness and good hot strength. An additional material, a new prehardened tool steel known as TOOLOX 44, exhibits control of the failure described above by optimizing the parameters of impact toughness that could reduce the heat-checking failures. A variety of heat treatment parameters exist for various reasons because the heat treatment operation is performed by a variety of companies. This issue of the diversity in heat treatments is resolved by TOOLOX 44; this steel is quenched and tempered in delivered state.
Decentralized Integral Nested Sliding Mode Control for Time Varying Constrained Modular and Reconfigurable Robot
Authors: Dong Bo , Li Yuanchun
Published: March 2015

This paper presents a novel decentralized integral nested sliding mode control approach for a time varying constrained modular and reconfigurable robot (MRR) and addresses the problem of joint trajectory tracking control of the MRR with strongly coupled model uncertainty. First, the dynamic model of the time varying constrained MRR is described as a synthesis of interconnected subsystems. Second, a decentralized control scheme is proposed based on only local dynamic information of each module. An integral nested sliding surface is implemented to reduce the chattering effect of the controller. Model uncertainties, including the unmodeled subsystem dynamics, the friction modeling error, and the interconnected dynamic coupling, are compensated by a variable gain supertwisting algorithm (VGSTA) based controller. The stability of the close-loop system is proved using the Lyapunov theory. Finally, simulations are performed for a time varying constrained 2-DOF MRR to study the effectiveness of the proposed method.
Analysis of Transport Policy Effect on CO2 Emissions Based on System Dynamics
Authors: Liu Shuang , Chen Shaokuan , Liang Xiao , Mao Baohua , Jia Shunping
Published: March 2015

CO2 emission from the transport sector attracts the attention of both transport and climate change policymakers because of its share in total green house gas emissions and the forecast of continuous growth reported in many countries. This paper takes the urban transport in Beijing as a case and builds a system dynamics model for analysis of the motorization trend and the assessment of CO2 emissions mitigation policy. It is found that the urban transport condition and CO2 emissions would be more serious with the growth of vehicle ownership and travel demand. Compared with the baseline do-nothing scenario, the CO2 emissions could be reduced from 3.8% to 24.3% in 2020 by various transport policies. And the policy of controlling the number of passenger cars which has been carried out in Beijing and followed by some cities could achieve good results, which may help to increase the proportion of public transit to 55.6% and reduce the CO2 emission by 18.3% compared with the baseline scenario in 2020.
Performance Analysis of Supercritical Binary Geothermal Power Plants
Authors: Dagdas Ahmet , Akkoyunlu Mustafa Tahir , Basaran Tugrul
Published: March 2015

It is possible to generate electricity by utilizing medium-temperature geothermal sources in various closed cycles. These geothermal power plants are very important and valuable as they utilize the sources which have low exergy. In recent years, medium-temperature sources that are around 150°C are used widely for electricity generation. In this study, performance of a supercritical binary power plant, that uses such a geothermal source, is analyzed to find the optimum turbine inlet pressure that maximizes power generation. In this power plant different working fluids are analyzed to find the appropriate fluid that maximizes power generation and efficiency. The observed working fluids are R134a, isobutane, R404a, n-Butane, and R152a. The performance of the plant is calculated with these fluids separately and it is found that the best fluid for performance is R152a for pure fluid and R404a for mixture fluid.
Research on Damping Noncoincidence and Its Influence Factors of Multibranch Hydropneumatic Suspension
Authors: Zhang Junwei , Chen Sizhong , Wu Zhicheng , Feng Jianbo , Fan Ying
Published: March 2015

Multibranch interconnected hydropneumatic suspension (MIHS) is increasingly applied in heavy multiaxle vehicle (HMV) for its superior characteristics, such as adjustable damping, and the antiroll and balancing axle load ability. However, as for multibranch hydropneumatic suspension, the stiffness and damping are coupled with each other tightly, which represents damping noncoincidence (DNC) problem. The DNC problem has become a key obstacle for developing suspension control technology and improving suspension performance. Firstly, a kind of MIHS structure is developed for an HMV, and the interconnected structure and principle are explained. Then the DNC problem is proposed and is given a description. And then, according to the researching needs, the suspension system model of single cylinder connected with multiple branches is built up based on the knowledge of state change of fluid and gas. Fourthly, the root cause of DNC problem is given according to simulation results. Fifthly, the impacts of three factors on DNC problem are studied, respectively, by adjusting excitation signal and system parameters in the simulation. The simulation results are quantitatively compared with regard to damping noncoincidence rate (DNCR). In the end, some conclusions are drawn based on the discussion and analysis and the future work is proposed.
Actuation of Pneumatic Artificial Muscle via Hydrogen Absorption/Desorption of Metal Hydride-LaNi5
Authors: Nuchkrua Thanana , Leephakpreeda Thananchai
Published: March 2015

This paper presents experimental studies on mechanical actuations of a pneumatic artificial muscle (PAM), which is driven by hydrogen gas based metal hydride (MH). The dynamic performances of hydrogen absorption/desorption, taking place within a MH reactor, are controlled via implementing cooling/heating effects of a thermoelectric module (TEM). Hydrogen pressure is applied as a driving force to commanding work outputs of the PAM as desired mechanical actuations. Due to strong inherent nonlinearity, a conventional proportional integral derivative (PID) control law is not capable of regulating thermodynamic variables of the HM reaction according to desired performances of the PAM. In this study, the fuzzy adaptive PID control is proposed in manipulating the MH reaction via the TEM. This viability of the proposed methodology is confirmed by the fact that the gains of PID control law are adapted by fuzzy rule-based tuning scheme at various operating conditions of the MH reactor. The experimental results show that the proposed control technique is much more effective than a PID control in both transient and steady state performances of the MH reactor for servo mechanical actuation of the PAM.
Mechanical and Microstructural Evaluation of DMAG Welding of Structural Steel
Authors: Mert Tolga , Gultekin Nurullah , Karaaslan Ahmet
Published: March 2015

Double channel torch, which allows concentric flow of two different shielding gases, was designed and manufactured in order to pursue double channel torch gas metal arc welding of unalloyed structural steel S235JR (EN 10025-2) with fourteen passes. Tensile and Charpy V-notch tests were realized and the results were compared with those of conventional gas metal arc welding. In order to evaluate mechanical testing results, microstructural analyses were conducted. It was found that the increase with double channel gas metal arc welding process in yield and tensile strengths as well as in toughness tests, especially in subzero temperatures, compared with conventional gas metal arc welding was due to longer columnar grains and finer tempered zone grain structure between passes and due to solidification and less dendritic structure formation in all-weld metal in double channel gas metal arc welding.
Study of Agglomeration Characteristics of Hydrate Particles in Oil/Gas Pipelines
Authors: Wang Wuchang , Li Yuxing , Liu Haihong , Zhao Pengfei
Published: March 2015

The force acting on hydrate particles is the critical factor to hydrate slurry stability which serves as fundamental basis for slurry flow assurance. A comprehensive analysis of forces acting on the hydrate particles was executed to determine the major agglomeration forces and separation forces, and comparison of forces reveals that the main agglomeration force is capillary force and the main separation force is shear force. Furthermore, four main influencing factors deciding the hydrate particle agglomeration were also analyzed and calculated, which shows contacting angle of capillary bridge is the most important factor for hydrate particles agglomeration, while interface tension of oil and water is the least important one. Some methods must be adopted to change the surface of hydrate agglomerates from hydrophile to lipophilicity so as to control the agglomeration of hydrate particle, which is the significant guarantee for safe flow of oil and gas transporting pipeline with hydrate particles.
Numerical and Experimental Investigations of Vortex Flows and Vortex Suppression Schemes in the Intake Passage of Pumping System
Authors: Yang Fan , Liu Chao
Published: March 2015

The three-dimensional turbulent flow in a vertical axial-flow pumping system with cube-type intake passage was simulated based on Navier-Stokes solver embedded with RNG k-∊ turbulence model. The internal flow pattern of the cube-type intake passage and the vorticity distribution around the bell-mouth of flare tube were analyzed. Four types of antisubmerged vortex devices were designed based on the vortex tubes intensity conservation theorem. The high-speed photography was applied to observe the flow pattern of the cube-type intake passage with 4 types of vortex-elimination devices. The predicted trajectory of submerged vortex was validated by the comparison with the tested results by PIV (particle image velocimetry). The results show that, with the increase of flowrate coefficient K Q, the maximum vorticity magnitude of every measuring line increases gradually and the increased amplitude of maximum vorticity magnitude decreases gradually. When a submerged vortex flows from the bottom of the cube-type intake passage into the flare tube, the position of maximum vorticity is closer to the center point of the bell-mouth than the initial position. Strong submerged vortex can be successfully suppressed by vortex-elimination device installation on the bottom of cube-type intake passage just below the bell mouth.
Automatic Heuristic Generation with Scatter Programming to Solve the Hybrid Flow Shop Problem
Authors: Shi Wen , Song Xueyan , Sun Jizhou
Published: March 2015

The hybrid flow shop (HFS) problem is solved in this study through composite dispatching rules (CDRs) generated automatically. CDR is a simple approach to solve the HFS problem rapidly and easily. Genetic programming (GP) is the most common methodology to generate CDRs to solve combinational optimization problems. The disruption in the main operations of GP, such as crossover and mutation, is high. Scatter programming is proposed in this paper to generate CDRs with improved scalability and flexibility for HFS problems. The proposed algorithm includes a novel local improvement method, one-point traversal shaking search, to accelerate convergence. Simulation studies demonstrate that the proposed algorithm outperforms genetic programming and scatter programming with shaking. The dispatching rules generated automatically can also be reused in similar instances and yield better results than existing dispatching rules. The rate of convergence of the proposed algorithm is higher than that of scatter programming with shaking.
Motorcyclist Protection Systems: Analysis of the Crash Test Tolerances of the European Technical Specification and the Spanish Standard
Authors: Miralbes Ramon
Published: March 2015

One of the most frequent and harmful kinds of motorcycle accidents is an impact against the post of the roadside barrier, so designers have developed some motorcyclist protection system (MPS) to reduce it. Some countries have developed a standard testing procedure, like the Spanish UNE-135900-2008 standard, identical to the CEN's recently approved Technical Specification (TS 1317-8). These standards specify the test procedure to obtain the behaviour of the MPS, but experimental tests have shown some dispersion of results for identical tests of the same barrier. There are some theories to explain this but the most reasonable is the influence of tolerances of some of the test variables in the final result like impact height, impact velocity, yaw angle, and mass. To analyze these theories, numerical analysis that can measure the independent influence of each parameter in the results has been used, using a correlated numerical model, a common and experimentally tested barrier, and an MPS. So, the results of this paper show how some parameters of impact significantly influence the behaviour of the system, changing impact severity, potential damage, and injuries. Therefore, the test tolerances do not guarantee repeatability and can accept systems too harmful for the same test conditions, so it will be necessary to reduce limit deviations of some impact variables.
Vehicle Group Relationship Transformation Mechanism under Dynamic and Complex Three-Lane Conditions
Authors: Zhang Jinglei , Wang Xiaoyuan , Wang Jianqiang , Ban Xuegang (Jeff)
Published: March 2015

A vehicle group is a dynamic spatial layout comprising a target vehicle and surrounding vehicles in the process of driving. It partly affects driving behavior states and guides driver propensity. Its formation and transformation mechanism are affected by driving behaviors all the time. It plays a significant role in research on active driving and autodriving systems by revealing the exact vehicle group transformation mechanism in a complex environment. Taking the three-lane condition as an example, a vehicle group is analyzed with the target vehicle running in different lanes. In addition, its state is recognized and a change rule is researched to reveal the transformation mechanism of a vehicle group in a time-varying environment. The current study establishes the basis for subsequent studies on the driver propensity transformation mechanism under complex, evolving environmental conditions.
Numerical Analysis of Liquid Sloshing Using the Incompressible Smoothed Particle Hydrodynamics Method
Authors: Aly Abdelraheem M. , Nguyen Minh Tuan , Lee Sang-Wook
Published: March 2015

A stabilized incompressible smoothed particle hydrodynamics (ISPH) method with the addition of a density invariant relaxation condition in the pressure calculations is applied to simulations of highly nonlinear liquid sloshing problems. By applying the Neumann boundary condition when solving pressure, the performance of the present ISPH method is enhanced significantly. Two large-amplitude free sloshing problems under a resonance sway excitation were carried out in a square and a rectangular tank with filling-depths ratios of 20% and 50% of tank height, respectively, and compared with the available published experimental results. To extend the validation of the method, numerical simulations for sloshing problems with the varying density of a floating body as well as a middle baffle, which also generates strongly nonlinear free surface flow, were conducted. The results showed that the present ISPH method produces smooth pressure distribution and significantly reduces spurious oscillation. The proposed ISPH method was shown to be robust and accurate in long time simulation of highly nonlinear sloshing problems.
OpenCV-Based Nanomanipulation Information Extraction and the Probe Operation in SEM
Authors: Li Dongjie , Song Jian , Wang Debao , Rong Weibin
Published: March 2015

Aimed at the established telenanomanipulation system, the method of extracting location information and the strategies of probe operation were studied in this paper. First, the machine learning algorithm of OpenCV was used to extract location information from SEM images. Thus nanowires and probe in SEM images can be automatically tracked and the region of interest (ROI) can be marked quickly. Then the location of nanowire and probe can be extracted from the ROI. To study the probe operation strategy, the Van der Waals force between probe and a nanowire was computed; thus relevant operating parameters can be obtained. With these operating parameters, the nanowire in 3D virtual environment can be preoperated and an optimal path of the probe can be obtained. The actual probe runs automatically under the telenanomanipulation system's control. Finally, experiments were carried out to verify the above methods, and results show the designed methods have achieved the expected effect.
The New Structure Design and Analysis of Energy Storage of Flywheel of Split Rotor
Authors: Xu Peng , Wang Wei , Yan Jin , Han Shaoyang
Published: March 2015

The braking of the rail transit train consumes a great quantity of energy, and the thermal energy produced in the process of braking can affect the normal operation of the transit train. Thus recycling the braking energy becomes a research hotspot of urban rail train. This paper made an overall analysis of regenerative braking process, the rationale, and the main features and then put forward the optimizing the structure of the composite flywheel concept and design calculation method. This paper also designs a new flywheel structure which can be applied on urban rail operating system. The new flywheel structure should be checked by finite element method and the radius of the rotor should be defined under the condition of meeting the requirements of carbon fiber material strength. Meanwhile, compared with the solid flywheel under the same condition, analysis shows that the maximum rotary inertia of the new flywheel and the quality energy density increased, and the discharge depth also perks up.
Time Resolved PIV Investigation on the Skin Friction Reduction Mechanism of Outer-Layer Vertical Blades Array
Authors: Park Seong Hyeon , An Nam Hyun , Yoon Hyun Sik , Park Hyun , Chun Ho Hwan , Lee Inwon
Published: March 2015

The drag reducing efficiency of the outer-layer vertical blades, which were first devised by Hutchins (2003), have been demonstrated by the recent towing tank measurements. From the drag measurement of flat plate with various vertical blades arrays by Park et al. (2011), a maximum 9.6% of reduction of total drag was achieved. The scale of blade geometry is found to be weakly correlated with outer variable of boundary layer. The drag reduction of 2.8% has been also confirmed by the model ship test by An et al. (2014). With a view to enabling the identification of drag reduction mechanism of the outer-layer vertical blades, detailed flow field measurements have been performed using 2D time resolved PIV in this study. It is found that the skin friction reduction effect is varied according to the spanwise position, with 2.73% and 7.95% drag reduction in the blade plane and the blade-in-between plane, respectively. The influence of vertical blades array upon the characteristics of the turbulent coherent structures was analyzed by POD method. It is observed that the vortical structures are cut and deformed by blades array and the skin frictional reduction is closely associated with the subsequent evolution of turbulent structures.
Large Eddy Simulation of Pulsating Flow before and after CoA Repair: CFD for Intervention Planning
Authors: Gårdhagen R. , Carlsson F. , Karlsson M.
Published: March 2015

Large eddy simulation was applied to investigate hemodynamics in a model with coarctation of the aorta (CoA) and poststenotic dilatation. Special focus was put on the role of hemodynamics for success of CoA repair. Several parameters previously identified as related to cardiovascular disease were studied. Known risk factors were observed both with CoA and after repair, and the restoration of the anatomy seems to be crucial for a successful result.
Protecting Intestinal Epithelial Cell Number 6 against Fission Neutron Irradiation through NF-κB Signaling Pathway
Authors: Chang Gong-Min , Gao Ya-Bing , Wang Shui-Ming , Xu Xin-Ping , Zhao Li , Zhang Jing , Li Jin-Feng , Wang Yun-Liang , Peng Rui-Yun
Published: March 2015

The purpose of this paper is to explore the change of NF-κB signaling pathway in intestinal epithelial cell induced by fission neutron irradiation and the influence of the PI3K/Akt pathway inhibitor LY294002. Three groups of IEC-6 cell lines were given: control group, neutron irradiation of 4Gy group, and neutron irradiation of 4Gy with LY294002 treatment group. Except the control group, the other groups were irradiated by neutron of 4Gy. LY294002 was given before 24 hours of neutron irradiation. At 6 h and 24 h after neutron irradiation, the morphologic changes, proliferation ability, apoptosis, and necrosis rates of the IEC-6 cell lines were assayed and the changes of NF-κB and PI3K/Akt pathway were detected. At 6 h and 24 h after neutron irradiation of 4Gy, the proliferation ability of the IEC-6 cells decreased and lots of apoptotic and necrotic cells were found. The injuries in LY294002 treatment and neutron irradiation group were more serious than those in control and neutron irradiation groups. The results suggest that IEC-6 cells were obviously damaged and induced serious apoptosis and necrosis by neutron irradiation of 4Gy; the NF-κB signaling pathway in IEC-6 was activated by neutron irradiation which could protect IEC-6 against injury by neutron irradiation; LY294002 could inhibit the activity of IEC-6 cells.
A Time-Series Model of Phase Amplitude Cross Frequency Coupling and Comparison of Spectral Characteristics with Neural Data
Authors: Lepage Kyle Q. , Vijayan Sujith
Published: March 2015

Stochastic processes that exhibit cross-frequency coupling (CFC) are introduced. The ability of these processes to model observed CFC in neural recordings is investigated by comparison with published spectra. One of the proposed models, based on multiplying a pulsatile function of a low-frequency oscillation (θ) with an unobserved and high-frequency component, yields a process with a spectrum that is consistent with observation. Other models, such as those employing a biphasic pulsatile function of a low-frequency oscillation, are demonstrated to be less suitable. We introduce the full stochastic process time series model as a summation of three component weak-sense stationary (WSS) processes, namely,θ,γ, andη, withηa1/fαnoise process. Theγprocess is constructed as a product of a latent and unobserved high-frequency processxwith a function of the lagged, low-frequency oscillatory component (θ). After demonstrating that the model process is WSS, an appropriate method of simulation is introduced based upon the WSS property. This work may be of interest to researchers seeking to connect inhibitory and excitatory dynamics directly to observation in a model that accounts for known temporal dependence or to researchers seeking to examine what can occur in a multiplicative time-domain CFC mechanism.
Urinary Angiopoietin-2 Is Associated with Albuminuria in Patients with Type 2 Diabetes Mellitus
Authors: Chen Shan , Li Huiqing , Zhang Chun , Li Zhenqiong , Wang Qiuyuan , Guo Jinting , Luo Changqing , Wang Yumei
Published: March 2015

Aims. To evaluate the levels of angiopoietin-1 (Ang-1), Ang-2, and vascular endothelial growth factor (VEGF) in serum and urine, and their association with albuminuria in patients with type 2 diabetes mellitus.Methods. In 113 type 2 diabetic patients with normoalbuminuria, microalbuminuria, and macroalbuminuria and 30 healthy controls, the levels of Ang-1, Ang-2, and VEGF in serum and urine were measured by enzyme-linked immunosorbent assay (ELISA).Results. Urinary and serum levels of Ang-2 were significantly higher in diabetic patients with normoalbuminuria than in healthy controls. Increased urinary Ang-2 level was positively associated with the degree of albuminuria. Urinary Ang-1 levels were significantly higher in normoalbuminuria patients and lower in macroalbuminuria patients than in controls. The levels of urinary VEGF increased in the albuminuria subgroup, though serum levels of Ang-1 and VEGF did not change. Urinary Ang-2 levels were correlated positively with albuminuria and negatively with glomerular filtration rate (GFR). Stepwise multiple regression analysis identified albuminuria (P<0.001) and GFR (P=0.001) as significant predictors of urinary Ang-2.Conclusions. Our data suggest that urinary Ang-2 is stepwise increased with renal damage in patients with type 2 diabetes mellitus and is associated with albuminuria.
A Practical Infrastructure for Real-Time Simulation across Timing Domains
Authors: Ma Yao-fei , Song Xiao , Wang Jiang-yun , Xiao Zhen
Published: March 2015

A real-time infrastructure, called MLRTI, is proposed in this paper to fulfill the requirement of real-time simulation in distributed environment. There are two novel contributions in this work. Firstly, a flexible timing mechanism is proposed to integrate external time source and local timer utility, enabling the distributed nodes to advance their timeline simultaneously at different speeds with high precision. A data transmission solution is also presented in which the reflective memory card (VMIC) is employed to provide fast data transmission with minimum delay. Secondly, a system partition schema is proposed in MLRTI to reduce the solution errors introduced by transforming a continuous system into distribution system, which is common in a class of control applications where the system is designed in centralized model but simulated in distributed environment for constrains on system structure or the need to balance computation load. Experiments are conducted and the results show this schema effectively reduces the possible errors by properly partitioning the system into parts that are suitable to be deployed in distributed environment.
On the Accelerated Settling of Fine Particles in a Bidisperse Slurry
Authors: Minkov Leonid L. , Stepanova Yuliya O. , Dueck Johann , Pikushchak Elizaveta V.
Published: March 2015

An estimation of increasing the volume average sedimentation velocity of fine particles in bidisperse suspension due to their capturing in the circulation zone formed in the laminar flow of incompressible viscous fluid around the spherical coarse particle is proposed. The estimation is important for an explanation of the nonmonotonic shape of the separation curve observed for hydrocyclones. The volume average sedimentation velocity is evaluated on the basis of a cellular model. The characteristic dimensions of the circulation zone are obtained on the basis of a numerical solution of Navier-Stokes equations. Furthermore, these calculations are used for modelling the fast sedimentation of fine particles during their cosedimentation in bidisperse suspension. It was found that the acceleration of sedimentation of fine particles is determined by the concentration of coarse particles in bidisperse suspension, and the sedimentation velocity of fine fraction is proportional to the square of the coarse and fine particle diameter ratio. The limitations of the proposed model are ascertained.
The Dynamics of an Impulsive Predator-Prey System with Stage Structure and Holling Type III Functional Response
Authors: Ju Zhixiang , Shao Yuanfu , Xie Xiaolan , Ma Xiangmin , Fang Xianjia
Published: March 2015

Based on the biological resource management of natural resources, a stage-structured predator-prey model with Holling type III functional response, birth pulse, and impulsive harvesting at different moments is proposed in this paper. By applying comparison theorem and some analysis techniques, the global attractivity of predator-extinction periodic solution and the permanence of this system are studied. At last, examples and numerical simulations are given to verify the validity of the main results.
Key Considerations in the Modeling of Tropical Maritime Microwave Attenuations
Authors: Lee Yee Hui , Meng Yu Song
Published: March 2015

This paper presents some key considerations for modeling of over-sea radio-wave propagations in 5 GHz band. The summarized information is based on a series of measurement campaigns which were recently carried out in the tropical maritime environments near Singapore. Multiray propagations and ducting of radio waves have been highlighted and considered in over-sea path loss modeling and prediction. It is noted that the sea-surface reflection is an important contribution in the received field, while the duct layers could enhance the radio-wave propagations. Our studies also show that the refracted ray inside evaporation duct could be a strong ray for short-range near sea-surface applications and needs to be properly evaluated.
Provenance Study of the Terracotta Army of Qin Shihuang’s Mausoleum by Fuzzy Cluster Analysis
Authors: Li Rongwu , Li Guoxia
Published: March 2015

20 samples and 44 samples of terracotta warriors and horses from the 1st and 3rd pits of Qin Shihuang’s Mausoleum, 20 samples of clay near Qin’s Mausoleum, and 2 samples of Yaozhou porcelain bodies are obtained to determine the contents of 32 elements in each of them by neutron activation analysis (NAA). The NAA data are further analyzed using fuzzy cluster analysis to obtain the fuzzy cluster trend diagram. The analysis shows that the origins of the raw material of the terracotta warriors and horses from 1st and 3rd pits are not exactly the same but are closely related to the loam soil layer near Qin’s Mausoleum while distant from the loess layers in the same area and remotely related to the Yaozhou porcelain bodies. It can be concluded that the raw material of the terracotta warriors and horses was taken from certain loam layer near Qin’s Mausoleum and the kiln sites might be located nearby.
The Diagnostic Accuracy of HE4 in Lung Cancer: A Meta-Analysis
Authors: Cheng Daye , Sun Ying , He Hu
Published: March 2015

The diagnostic value of serum HE4 in patients with lung cancer remains controversial. Thus, we performed a systematic review and meta-analysis to assess the diagnostic accuracy of serum HE4 for lung cancer. We conducted a comprehensive literature search in PubMed, EMBASE, Chinese National Knowledge Infrastructure (CNKI), and WANFANG databases between Jan. 1966 and Nov. 2014. The diagnostic sensitivity (SEN), specificity (SPE), positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and summary receiver operating characteristic curve (SROC) were pooled by Meta-DiSc 1.4 software. A total of seven articles including 715 cases and 549 controls were included for analysis. The summary estimates for serum HE4 in the diagnosis of lung cancer in these studies were pooled SEN 0.72 (95% CI: 0.68–0.75), SPE 0.85 (95% CI: 0.81–0.88), PLR 4.68 (95% CI: 3.23–6.78), NLR 0.31 (95% CI: 0.24–0.39), and DOR 17.14 (95% CI: 9.72–30.20), and the area under the curve (AUC) was 0.8557. This meta-analysis indicated that serum HE4 is a potential tool in the diagnosis of lung cancer. In addition, considering the high heterogeneity and potential publication bias, further studies with rigorous design and large sample size are needed in the future.
Design of a Discrete Tracking Controller for a Magnetic Levitation System: A Nonlinear Rational Model Approach
Authors: Gómez-Salas Fernando , Wang Yongji , Zhu Quanmin
Published: March 2015

This work proposes a discrete-time nonlinear rational approximate model for the unstable magnetic levitation system. Based on this model and as an application of the input-output linearization technique, a discrete-time tracking control design will be derived using the corresponding classical state space representation of the model. A simulation example illustrates the efficiency of the proposed methodology.
Norms and Spread of the Fibonacci and Lucas RSFMLR Circulant Matrices
Authors: Xu Wenai , Jiang Zhaolin
Published: March 2015

Circulant type matrices have played an important role in networks engineering. In this paper, firstly, some bounds for the norms and spread of Fibonacci row skew first-minus-last right (RSFMLR) circulant matrices and Lucas row skew first-minus-last right (RSFMLR) circulant matrices are given. Furthermore, the spectral norm of Hadamard product of a Fibonacci RSFMLR circulant matrix and a Lucas RSFMLR circulant matrix is obtained. Finally, the Frobenius norm of Kronecker product of a Fibonacci RSFMLR circulant matrix and a Lucas RSFMLR circulant matrix is presented.
Establishment of Track Quality Index Standard Recommendations for Beijing Metro
Authors: Liu Reng-Kui , Xu Peng , Sun Zhuang-Zhi , Zou Ce , Sun Quan-Xin
Published: March 2015

Since 2007, Beijing Metro started to use track geometry car to measure quality of its tracks under wheel loading conditions. The track quality measurement data from the track geometry car were only used to assess local track quality by means of scoring 1000 m long track segments based on track exceptions. Track quality management experience of national railroads of China shows that, in addition to local track quality assessment, an overall track quality assessment method should be employed. The paper presented research results funded by Road Administration of Beijing Municipal Commission of Transport. The paper proposed an overall track quality assessment method for Beijing Metro and determined the overall track quality standards by means of a statistical method which was proposed in the paper. The standards are necessary for the proposed method to be applied and have been approved by Road Administration of Beijing Municipal Commission of Transport and put into practice.
Optimal Control Problem of Converter Steelmaking Production Process Based on Operation Optimization Method
Authors: Zhang Jun
Published: March 2015

Dynamic operation optimization has been utilized to realize optimal control problem for converter. The optimal control indicator is determined via current state of converter smelting production process, and the set values of operation variable would control converter production. Relationship between various operating variables, current temperature, and carbon content is constructed through operation analysis of a great deal of actual production data; then, the dynamic optimal control indicator is derived from historical excellent smelting data; finally, the dynamic operation optimization model is built by taking the minimum deviation between the current data—molten steel temperature and carbon content—and optimal data which are determined by the optimal control indicator as objective function. DE (differential evolution) with improved strategy is used to solve the proposed model for obtaining the set values of each operating variable, which is beneficial for further control. Simulation of actual production data shows the feasibility and efficiency of the proposed method. That proved that the proposed method solves the optimal control problem of converter steelmaking process as well.
Safety and Visual Outcome of Visian Toric ICL Implantation after Corneal Collagen Cross-Linking in Keratoconus: Up to 2 Years of Follow-Up
Authors: Antonios Rafic , Dirani Ali , Fadlallah Ali , Chelala Elias , Hamade Adib , Cherfane Carole , Jarade Elias
Published: March 2015

Purpose. To evaluate the long-term safety and clinical outcome of phakic Visian toric implantable collamer lens (ICL) insertion after corneal collagen cross-linking (CXL) in progressive keratoconus.Methods. This was a retrospective study of 30 eyes (19 patients), with progressive keratoconus, who underwent sequential CXL followed by Visian toric ICL implantation after 6 months.Results. At baseline, 6 eyes had stage I, 14 eyes stage II, and 10 eyes stage III keratoconus graded by Amsler-Krumeich classification. At 6 months after CXL, onlyK(steep) andK(max) decreased significantly from baseline, with no change in visual acuity or refraction. Flattening in keratometric readings was stable thereafter. There was significant improvement in mean uncorrected distance visual acuity (1.57 ± 0.56 to 0.17 ± 0.06 logMAR,P<0.001) and mean corrected distance visual acuity (0.17 ± 0.08 to 0.11 ± 0.05 logMAR,P<0.001) at 12 months after ICL implantation that was maintained at the 2-year follow-up. Mean cylinder power and mean spherical equivalent (SE) also decreased significantly after ICL implantation. A small hyperopic shift in SE (+0.25 D) was observed at 2 years that did not alter visual outcomes.Conclusions. Visian toric ICL implantation following CXL is an effective option for improving visual acuity in patients with keratoconus up to 2 years.
Inactivation of Src-to-Ezrin Pathway: A Possible Mechanism in the Ouabain-Mediated Inhibition of A549 Cell Migration
Authors: Shin Hye Kyoung , Ryu Byung Jun , Choi Sik-Won , Kim Seong Hwan , Lee Kyunglim
Published: March 2015

Ouabain, a cardiac glycoside found in plants, is primarily used in the treatment of congestive heart failure and arrhythmia because of its ability to inhibit Na+/K+-ATPase pump. Recently ouabain has been shown to exert anticancer effects but the underlying mechanism is not clear. Here, we explored the molecular mechanism by which ouabain exerts anticancer effects in human lung adenocarcinoma. Employing proteomic techniques, we found 7 proteins downregulated by ouabain in A549 including p-ezrin, a protein associated with pulmonary cancer metastasis in a dose-dependent manner. In addition, when the relative phosphorylation levels of 39 intracellular proteins were compared between control and ouabain-treated A549 cells, p-Src (Y416) was also found to be downregulated by ouabain. Furthermore, western blot revealed the ouabain-mediated downregulation of p-FAK (Y925), p-paxillin (Y118), p130CAS, and Na+/K+-ATPase subunits that have been shown to be involved in the migration of cancer cells. The inhibitory effect of ouabain and Src inhibitor PP2 on the migration of A549 cells was confirmed by Boyden chamber assay. Anticancer effects of ouabain in A549 cells appear to be related to its ability to regulate and inactivate Src-to-ezrin signaling, and proteins involved in focal adhesion such as Src, FAK, and p130CAS axis are proposed here.
Intramyocardial Dissection following Postinfarction Ventricular Wall Rupture Contained by Surrounding Postoperative Adhesions
Authors: Ercan Abdulkadir , Gurbuz Orcun , Kumtepe Gencehan , Ozkan Hakan , Karal Ilker Hasan , Velioglu Yusuf , Ener Serdar
Published: March 2015

Introduction. Dissection of the myocardium is a rare form of cardiac rupture, caused by a hemorrhagic dissection among the spiral myocardial fibers, its diagnosis is rarely established before the operation or death, and extremely few cases have been reported in the literature and none of these cases seem to have a history of previous cardiac surgery which makes our report unique.Case Presentation. A 61-year-old female patient was admitted into the emergency room with complaints of progressive chest pain for 2 days. She had a history of second time prosthetic aortic valve replacement and was under anticoagulation therapy. She was diagnosed with an acute inferoposterior myocardial infarction and underwent emergency coronary angiography revealing spontaneous recanalization of the right coronary artery. During the follow-up, she developed cardiogenic shock and a new occurring systolic ejection murmur. Transthoracic echocardiography showed a left ventricular free wall rupture; then, she was taken in for emergency surgery. During the operation, a rupture zone and a wide intramyocardial dissecting area were detected. Intraventricular patch repair technic with autologous pericardial patch was used to exclude the ruptured area. Following the warming period, despite adequate hemostasis, hemorrhage around suture lines progressively increased, leading to the patient’s death.Conclusion. Pericardial adhesions might contain left ventricular rupture leading to intramyocardial dissection.
Robust Proactive Project Scheduling Model for the Stochastic Discrete Time/Cost Trade-Off Problem
Authors: Li Hongbo , Xu Zhe , Xiong Li , Liu Yinbin
Published: March 2015

We study the project budget version of the stochastic discrete time/cost trade-off problem (SDTCTP-B) from the viewpoint of the robustness in the scheduling. Given the project budget and a set of activity execution modes, each with uncertain activity time and cost, the objective of the SDTCTP-B is to minimize the expected project makespan by determining each activity’s mode and starting time. By modeling the activity time and cost using interval numbers, we propose a proactive project scheduling model for the SDTCTP-B based on robust optimization theory. Our model can generate robust baseline schedules that enable a freely adjustable level of robustness. We convert our model into its robust counterpart using a form of the mixed-integer programming model. Extensive experiments are performed on a large number of randomly generated networks to validate our model. Moreover, simulation is used to investigate the trade-off between the advantages and the disadvantages of our robust proactive project scheduling model.
Balloon Dilatation of a Case of Tuberculous Tracheobronchial Stenoses during the Course of Antituberculous Treatment
Authors: Nour Moursi Ahmed Shimaa , Korrungruang Potjanee , Saka Hideo , Asai Gyo , Ise Yuko , Kitagawa Chiyoe , Oki Masahide
Published: March 2015

We report a case of posttuberculosis (TB) tracheobronchial stenoses presented with progressive exertional dyspnea during the course of anti-TB treatment. An 83-year-old Japanese man was admitted for progressive dyspnea; chest X-ray and CT showed stenosis of distal trachea and left main bronchus. Pulmonary function test revealed reduction of FEV1. Balloon dilatation without stent insertion was the choice for this patient for multiple reasons with marked improvement of symptoms.
Dynamic Analysis of a Delayed Reaction-Diffusion Predator-Prey System with Modified Holling-Tanner Functional Response
Authors: Pan Xinhong , Zhao Min , Dai Chuanjun , Wang Yapei
Published: March 2015

A predator-prey model with modified Holling-Tanner functional response and time delays is considered. By regarding the delays as bifurcation parameters, the local and global asymptotic stability of the positive equilibrium are investigated. The system has been found to undergo a Hopf bifurcation at the positive equilibrium when the delays cross through a sequence of critical values. In addition, the direction of the Hopf bifurcation and the stability of bifurcated periodic solutions are also studied, and an explicit algorithm is obtained by applying normal form theory and the center manifold theorem. The main results are illustrated by numerical simulations.