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Excessive plastic deformation may occur at the beam-column joints under seismic action and lead to connection failure, increasing the possibility of collapse of the entire frame structure. In order to improve the seismic performance of assembled steel structure joints, a right-angle viscoelastic joint damper with polyurethane as the core energy dissipation material is proposed in this paper. First, the temperature scanning tests of polyurethane materials were carried out based on the dynamic mechanical analysis method. Second, the dynamic mechanical test and numerical simulation analysis of the designed right-angle viscoelastic damper were performed to reveal the dynamic energy dissipation characteristics of the right-angle damper. Finally, the dynamic time-history damping analysis was performed on the steel frame structure equipped with RVDs. The results show that the TA value of polyurethane material reached its peak at 2.0 Hz, which is the ideal frequency for the material’s damping ability. The right-angle damper made of polyurethane material has a softening nonlinear characteristic, and the peak value of the loss factor was obtained at 2.0 Hz, which is consistent with the results of the dynamic performance of the polyurethane material. The numerical simulation results demonstrate that stress on the steel plates and viscoelastic layers is reasonable. When the excitation level did not exceed 9 mm displacement amplitude, the energy input to the damper was dissipated by polyurethane, and the steel plates never showed plastic deformation. The time-history analysis of the steel structure shows that the dampers designed in this paper have a good control effect on the interstory displacement, acceleration, and interstory shear force of the structure. The research results lay the necessary foundation for the engineering application of polyurethane materials in the field of beam-column joints vibration damping. more...

Five samples of the nylon fabric laminated rubber bearing were manufactured with different rubber layer thickness and nylon cloth specifications. The compression and compression shear tests were conducted to evaluate the mechanical properties of the bearings. Results show the novel bearings’ vertical stiffness is significantly lower than that of laminated steel rubber bearings, but their vertical damping ratio can reach 7%. The effective horizontal stiffness decreases with increasing shear strain due to rollover deformation. The bearings do not get seriously damaged when the shear strain is 300%. The equivalent damping ratio of the bearings varies in the range of 9%–13%. more...

Large-displacement corner deformation often occurs at the joints of towering structures and long-span space structures subjected to strong earthquake. In order to improve the energy dissipation capacity of structural joints, the Nitrile Butadiene Rubber/High Abrasion Furnace Black (NBR/HAF) high damping composite was fabricated by formulation optimization in this paper, where a nonlinear large-deformation viscoelastic joint damper was proposed. The damper consists of five layers of restrained steel plates and four layers of shear energy dissipating material, which can reach 60[Formula: see text]mm shear displacement. In this paper, dynamic mechanical performance tests and static mechanical tests were firstly conducted on the core energy dissipating media of the damper. The loss factor of NBR/HAF composite reached a peak of 1.51 at about [Formula: see text]C, while its wide damping temperature range was [Formula: see text]C. Second, the accuracy of the simulation method was verified by comparing the simulated and experimental hysteresis curves. Then, the refined numerical simulation of this damper was carried out using ABAQUS finite element software with the high damping material as its core energy dissipating media. Finally, the magnitude and type of energy dissipation of each part of the viscoelastic joint damper under different loads were investigated. It was found that the large-deformation viscoelastic joint damper based on the composite had good damping capacity. Its dynamic characteristics were affected by the displacement amplitude and excitation frequency, which exhibited hardening nonlinear characteristics. As the frequency and load amplitude increased, the peak displacement in the loading direction gradually decreased, whereas the total energy input to the damper and the energy dissipated by the viscoelastic material increased monotonically. The input energy was only dissipated by the viscoelastic material, and no plastic loss occurred in the steel plate during the entire loading stage. Under high frequency and large loads, the damper can also have good energy dissipation characteristics. Because of the negative strain energy caused by plastic dilatancy, the energy dissipated by the material was gradually greater than the input energy with the load increasing. more...

Estrogen deficiency induces cardiac dysfunction and increases the risk of cardiovascular disease in postmenopausal women and in those who underwent bilateral oophorectomy. Previous evidence suggests that puerarin, a phytoestrogen, exerts beneficial effects on cardiac function in patients with cardiac hypertrophy. In this study, we investigated whether puerarin could prevent cardiac hypertrophy and remodeling in ovariectomized, aortic-banded rats. Female SD rats subjected to bilateral ovariectomy (OVX) plus abdominal aortic constriction (AAC). The rats were treated with puerarin (50 mg·kg(−1) ·d(−1), ip) for 8 weeks. Then echocardiography was assessed, and the rats were sacrificed, their heart tissues were extracted and allocated for further experiments. We showed that puerarin administration significantly attenuated cardiac hypertrophy and remodeling in AAC-treated OVX rats, which could be attributed to activation of PPARα/PPARγ coactivator-1 (PGC-1) pathway. Puerarin administration significantly increased the expression of estrogen-related receptor α, nuclear respiratory factor 1, and mitochondrial transcription factor A in hearts. Moreover, puerarin administration regulated the expression of metabolic genes in AAC-treated OVX rats. Hypertrophic changes could be induced in neonatal rat cardiomyocytes (NRCM) in vitro by treatment with angiotensin II (Ang II, 1 μM), which was attenuated by co-treatemnt with puerarin (100 μM). We further showed that puerarin decreased Ang II-induced accumulation of non-esterified fatty acids (NEFAs) and deletion of ATP, attenuated the Ang II-induced dissipation of the mitochondrial membrane potential, and improved the mitochondrial dysfunction in NRCM. Furthermore, addition of PPARα antagonist GW6471 (10 μM) partially abolished the anti-hypertrophic effects and metabolic effects of puerarin in NRCM. In conclusion, puerarin prevents cardiac hypertrophy in AAC-treated OVX rats through activation of PPARα/PGC-1 pathway and regulation of energy metabolism remodeling. This may provide a new approach to prevent the development of heart failure in postmenopausal women. more...

The stochastic modeling and synthesis of near-fault forward-directivity ground motions for the prescribed seismic scenario is presented in this study. This stochastic model, which is established in the orientation of the strongest pulse, combines the directivity pulse component represented by the Gabor wavelet pulse model and the high-frequency component characterized by the modulated filtered white noise model. In this regard, the pulse feature, evolutionary intensity and frequency contents are reasonably considered. Then, the empirical predictive equations that relate the parameters of the proposed stochastic model to the variables that describe earthquake source, path, site conditions, and near-fault rupture-to-source geometry are developed based on both regression and correlation analysis. The basic procedure for the synthesis of possible forward-directivity ground motions under the prescribed seismic scenario is provided as well. The efficacy of the stochastic model and the simulation procedure is confirmed by comparing the simulated motions with the recorded ones in terms of time-series and response spectra values, which indicate that the synthetic ground motions are capable of reproducing the salient characteristics, as well as the natural variability, of the recorded ones. Therefore, the proposed stochastic modeling and simulation method is expected to be a desirable alternative and complement for recorded ground motions in the near-fault seismic risk assessment. more...

A new type of square reinforced concrete frame column with a hollow section and spiral stirrups at the section corners is proposed. To investigate its seismic performance, three full-scale columns of this type and one full-scale conventional solid column were designed and tested under a quasi-static load. The failure mode, load-bearing, deformation, and energy-dissipation capacities of the proposed column were evaluated and compared with those of the solid column. The effects of the cavity ratio and axial load on the seismic performance were investigated. more...

Predicting the ultimate behavior of elastomeric bearings subjected to combined compression-shear loading is an indispensable part of quantitatively evaluating the performance of seismic isolated structures during earthquakes. In this paper, the initial critical load derived from three different approximations for bending modulus are analyzed and evaluated by existing experimental data. Then, Finite Element (FE) models of bearings are developed and validated by critical load results. Based on that, a parametric FE study is performed to investigate the failure mode of bearings under this combined loading. It is demonstrated that the bending modulus based on the pressure solution and further simplification provides a more reasonable estimate of initial critical load. The predicting capacity of the overlapping area method for the general trend of critical load is improved with the increasing of external diameter. The dividing line between stability limit and shear failure is dominated by the second shape factor. Furthermore, as the first shape factor increases, the ultimate shear deformation corresponding to shear failure slightly increases. more...

This paper presents a numerical model for accurately representing the behaviors of lead-rubber bearings during earthquakes. This model, which is implemented in OpenSees as a user-defined element, accounts for the mechanical characteristics of bearings as follows: firstly, the bi-lateral interaction effect of hysteretic behaviors, as well as the variation in horizontal stiffness due to vertical load, is considered; secondly, the reduced vertical stiffness under large lateral displacement is incorporated by the piecewise linear formulation, and the linear reduction method is employed to determine the stability limit of bearings in the deformed configuration; furthermore, the cavitation and permanent damage effects in bearings are mathematically included. To validate the numerical model, simulation analyses are performed for a series of static and dynamic loading tests, and the numerical results show reasonable agreement with experimental ones, which indicates that the proposed model provides an effective tool for the failure mode analyses of bearings and the dynamic analyses of seismic isolated structures. more...

For the purpose of grasping the stress state, vibration characteristics and safety of the steel arch in Nanjing Olympic Sports Center, which is the main support among the stadium roof system as well as the world's largest oblique arch structure, a real-time health monitoring system was established and the main achievements including the system constitution, monitoring items and layouts of measuring points were described. The monitoring data measured during the 2 years period from 2014 to 2016 as well as the SAP2000 finite element software were combined to conduct the status identification and safety evaluation. The results show that the simulation results are consistent with the measured date; The measured alignment of the large arch is relatively stable, although the structural stiffness of arch has weakened compared with the designed state, the low order vibration frequencies are stable during the 2 years period; The stress state of each monitoring component is at safe levels, and fluctuates within a small range affected by the extreme seasonal temperature changes. more...

Base isolation is an efficient method to reduce the vulnerability of structures in high seismic risk zones. As the core component, the performance of the isolation bearings greatly affects the safety and reliability of the isolation system. In this paper, a series of compression shear tests were performed on three scaled rubber bearings, test temperatures range from −30 to 20 °C and different levels of shear strains were considered. Experimental results show that a negligible variation in the performance parameters is associated to the change in shear strain, and characteristics of the bearings such as the equivalent stiffness, yield force and post-yield stiffness can be significantly affected by the temperature. Then the influence coefficient functions able to take into account the influence of temperature were formulated, and the analysis values at different temperatures are in good agreement with the corresponding experimental values. The temperature influence coefficient function can be used to predict the mechanical properties of rubber bearings at different temperatures. more...

To investigate the cracking and failure performance of various forms for slabs, experimental studies on layered slabs and integral slabs under linear loading and cyclic incremental loading are carried out. The reliable numerical simulation based on the solid element is proposed and the reliability of the method is verified. The main three factors affecting cracking and failure performance of slab are calculated and analysed. The results show that the cracking and failure phenomenon and performance of the slabs with the layered slabs and integral slabs are different. The bearing capacity and mechanical performance of the integral slab are better than the layered slab. The slab cracking load, initial stiffness, and bearing capacity are affected by the slab thickness, the rebar ratio, and the proportion of the surface part, which need to be considered in the slab design. more...

Strip shape defects, especially the crown problem, once appeared in the production of hot-rolled strip steel in SG Company. The macroscopic characteristic is the thickness difference occurred between the center and edge cross section of hot-rolled plate. Morphological characteristics and forming reasons can be got by analyzing roll wear. Research shows that the main reason for the formation of crown is excessive attrition of work roll in later period, which leading to smaller roll shape. Therefore, shape defects have been effectively controlled after introducing CVC roll contour technology to optimize roll shape. Quality qualified rate of strip shape of hot-rolled strip steel is more than 99.6% percent, and it has been successfully put into application of hot rolling mill. more...

This paper studied on vibration energy dissipation analysis of a shear wall structure with viscous liquid dampers for reinforcement and reconstruction. Viscous liquid dampers and herringbone steel shotcrete were used for seismic control and the elastic-plastic time history analysis had been carried out. The results show that: the first layer shear force decreases. The minimal average damping rate of layer displacement in X direction is 4.68% and the maximum is 12.92%; the minimal average damping rate of layer displacement in Y direction is 6.47% and the maximum is 19.8%. So using viscous fluid dampers , the vibration response of the structure could be effectively reduced． more...

The driving security of trains at high speeds is among the pivotal issues significantly affected by the smoothness of rail lines. For high-speed railway steel bridges, the fatigue cracking of typical positions under the rail lines will reduce the stiffness of the deck plate, inducing the smoothing of the rail lines. In this paper, a new theoretical approach is proposed that integrates the fatigue assessment of a typical welded joint for high-speed railway steel bridges in service. Based on the strain history data recorded by a structural health monitoring system, the theoretical approach includes various factors, including stress concentration, environmental corrosion, and train flow. Upon application in an actual high-speed railway bridge with an orthotropic steel deck, the approach was used to conduct determinative and reliable fatigue-life evaluation of the bridge. A static-load experiment was conducted to obtain the stress distribution around the weld and the difference in stress between the p... more...

Aimed at the human comfort problem with cantilevered floors arising from normal human activities, the Tuned Mass Dampers are used to control the vibration of the steel cantilevered floors which span 16.3m. Based on studies on the dynamic characteristics of the overall structure, with the position of TMDs optimized and the parameters set reasonably, the vertical vibration response of the cantilevered floors under different cases of pedestrian walking loads is calculated. The results show that the TMD system can effectively reduce the dynamic response of the cantilevered floors, in order to meet the requirements of human comfort. more...

This paper addresses the quantification of environmental variability of wavelet packet energy spectrum (WPES) extracted from the ambient dynamic responses of a suspension bridge using wavelet packet transform (WPT). The daily averaged WPES using multi-sample averaging technique are first obtained to eliminate the inherent randomness arising from the identification algorithm. Then the effect of temperature on the measured WPES is quantified using the seasonal correlation models. The traffic-induced and wind-induced variability are further quantitatively evaluated by establishing the traffic-WPES and wind-WPES correlation models. The analysis results reveal that temperature and inherent randomness are the critical sources causing WPES variability, and the WPES variability caused by wind speed and traffic loadings is negligible compared with temperature and inherent randomness. Considering seasonal correlation models of temperature-WPES can effectively eliminate the temperature effect and inherent randomness, it is suitable for structural damage warning of long-span bridges if future seasonal correlation models deviate from these normal models. more...

Static load tests are conducted for two outer-plated steel-concrete continuous composite beams. Performance of the tested beams, including the load-deflection curve，load-strain curve，load-moment curve, plastic-hinge region and the crack of concrete flange of specimens, is analyzed. The test results indicate that effective cooperation can be achieved by the shear connector between the concrete part and the outer-plated steel beam; the composite beams have good overall performance. The concrete filling inside the U-shaped steel beam enhances the global and local stability of the outer-plated steel beam. At the bearing capacity limit state, the plastic strain on sections of both the negative and positive maximum moment develops fully so that ideal plastic hinges are formed relatively. At the serviceability limit state, the deformation and the crack width of continuous composite beams can be controlled effectively. more...

A structural damage alarming method is proposed using empirical mode decomposition. The basic idea of this method is that with respect to the intact model and damaged models, the energy redistribution of the intrinsic mode functions decomposed from the structural response can represent the variation of the structural dynamic characteristics caused by the structural damage. By taking the Benchmark test model as the research object, the structural dynamic responses from the hammer-impact tests are collected then the damage alarming parameters and the damage alarming indices are evaluated. The experimental results reveal that the structural damage alarming indices based on empirical mode decomposition is able to effectively detect the structural initial damage with preferable damage alarming capacity. more...

This paper presented a new mild steel slit damper(SSD). The new shape was parabolic according to all the cross section having the same maximal stress, and the elastic stiffness and yield displacement formula were derived. Finite element analysis showed that the parabolic shaped damper had a more reasonable load - displacement curve compared with the previously proposed shape. The theoretical stiffness and yield displacement were consistent with the results by finite element method (FEM), and that indicated the presented design method was simple and feasible. more...

To study the seismic performance of RC shear wall, and to develop its fine nonlinear analysis method, systemic studies on nonlinear static analysis and it’s realization method are carried out. Beginning with rotating-angle softened-truss model for coupled shear and flexural responses, analytical model of solid wall is presented based on the comparative study on four types of constitutive law of concrete for confined concrete of boundary zone. Good agreements between analytical and experimental results of load-displacement relation are found, which indicates that the proposed analytical method can reflect the global mechanical behavior of shear wall well. Studies on coupling beam and global perforated wall modeling are implemented, then modeling approach and nonlinear static analysis method for perforated wall are proposed. Comparing analytical load-displacement curve to experimental, initial stiffness and first turning point agree well and analytical ultimate capacity is close to experimental, which is shown that the load-displacement curve can actually exhibit the general load-displacement trend of perforated wall. more...

The damage alarming analysis based on wavelet packet energy spectrum is performed with regard to the experimental data of Benchmark steel frame structure and online monitoring data of Runyang Suspension Bridge, on the basis of which the damage alarming effects using various wavelet functions are investigated in detail. Results reveal that the Daubechies wavelet functions and Coiflets wavelet functions are applicable to structural damage alarming. more...

Xijiang River Bridge is the first hybrid railway bridge composed of single pylon cable-stayed and continuous rigid-frame system in China. To study the mechanical behaviors of the novel bridge, 3-D finite element model (FEM) based on Midas/Civil software is created; spatial effect of stayed cable is discussed; the self-vibration behavior of this unique bridge is analyzed by adopting the subspace iteration method; then by means of simulating analysis of the whole construction process, stress paths of critical parts in different construction stages are calculated and presented to study its mechanical behaviors. Results reveal that the composite bridge embodies features of both traditional cable-stayed bridge and rigid-frame bridge. Further study, however, shows that the unique hybrid system is mostly characterized by the rigid-frame type, meanwhile, as safety storage, the stay cable will play an important role in the “stiffness kept” of the whole structure, improving the actual stress and working condition of the whole structure in the long run. more...

The buckling-restrained braces(BRBs) with low yield strength(LYS) steel make good use of ductility and hysteretic energy dissipation of the low yield strength steel and are gradually applied in structural vibration. To foster BRBs with low yield strength steel in China mainland, the domestic LYS160 was used in BRB. The cross section was a simple shape. A static cyclic test was carried out, and the finite element analysis was conducted. The results show that the BRB with domestic low yield strength steel has good ductility, hysteretic energy dissipation and resistance to fatigue. A shaped cross section is simple and easy to promote application in China mainland. more...

// Xiaobo Li 1 , Yang lv 2 , Na Gao 1 , Hao Sun 1 , Runze Lu 1 , Hongbao Yang 3 , Chengcheng Zhang 1 , Qingtao Meng 1 , Shenshen Wu 1 , Ai-Qun Li 4 , Yankai Xia 5, * , Rui Chen 1, 6, * 1 Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China 2 Department of Histology and Embryology, Hebei North University, Zhangjiakou, 075000, China 3 Center for Drug Safety Evaluation and Research, China Pharmaceutical University, Nanjing, 211198, China 4 School of Public Health, Medical College, Wuhan University of Science and Technology, Wuhan, 430081, China 5 Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing 210009, China 6 State Key Laboratory of Bioelectronics, Southeast University, Nanjing, 210096, China * These authors have contributed equally to this work Correspondence to: Rui Chen, e-mail: 101011816@seu.edu.cn Yankai Xia, e-mail: yankaixia@njmu.edu.cn Keywords: PM 2.5 , microRNA, lung cancer, carcinogenesis, actin Received: February 19, 2016 Accepted: April 10, 2016 Published: April 26, 2016 ABSTRACT Recent studies have linked ambient fine particulate matter (PM 2.5 ) to increased lung cancer mortality and morbidity. However, the underlying mechanism causing the adverse effects of PM 2.5 is less clear. In the present study, post-transcriptional profiling was used to explore biological pathways involved in PM 2.5 -induced pulmonary disorders. The carcinogenesis and metastasis of PM 2.5 exposure were evaluated by long-term PM 2.5 exposure tests. We observed dysregulation of actin in A549 cells line and dysplasia in the lungs of mice exposed to PM 2.5 . Both PM 2.5 -exposed cells and animals showed increased Rnd3 expression levels. Moreover, miR-802 mimics rescued actin disorganization in vitro and alveolitis in vivo . Long-term exposure to PM 2.5 promoted carcinogenesis and metastasis of pulmonary cells. Decreased miR-802 expression levels in the serum samples of PM 2.5 -treated mice and individuals from moderately polluted cities were observed. Increased Rnd3 expression levels in lung cancers tissues have been identified by a genome database TCGA, and have been linked to less overall survival probabilities of lung cancer patients. Our findings suggest that dysregulation of actin cytoskeleton and down-regulation of miR-802 expression might be the underlying mechanism involved in the adverse effects of PM 2.5 exposure. In addition, long-term exposure to PM 2.5 demonstrated strong associations with malignant pulmonary disorders. more...

Fatigue life assessment of critical bridge members using online monitoring data has been investigated in recent years. To make a quick and efficient evaluation, a representative block of strain cycles is usually defined. However, such block sometimes fails to cover the change in fatigue damage by temperature fluctuation and traffic growth, which is important to the life prediction of the welds in a long-span suspension bridge. To find the influence of temperature and traffic volume on the fatigue damage, an equivalent vehicle load method is dedicated through finite element analysis, and the statistical disposition of traffic flow has been conducted, using data from the Runyang Bridge. The influence of traffic growth can be estimated and eliminated from the total damage so that the temperature effect on the fatigue damage is finally obtained. It is found that temperature has a linear effect on the fatigue damage. According to the fitted relationship between fatigue damage, temperature and the traffic flow, a more objective fatigue assessment is undertaken, based on the rain-flow counting method and the Palgren-Miner rule. more...

This paper describes a study on damage identification using wavelet packet analysis and neural networks. The identification procedure could be divided into three steps. First, structure responses are decomposed into wavelet packet components. Then, the component energies are used to define damage feature and to train neural network models. Finally, in combination with the feature of the damaged structure response, the trained models are employed to determine the occurrence, the location and the qualification of the damage. The emphasis of this study is put on multi-damage case. Relevant issues are studied in detail especially the selection of training samples for multi-damage identification oriented neural network training. A frame model is utilized in the simulation cases to study the sampling techniques and the multi-damage identification. Uniform design is determined to be the most suitable sampling technique through simulation results. Identifications of multi-damage cases of the frame including different levels of damage at various locations are investigated. The results show that damages are successfully identified in all cases. more...

Our previous study elucidated that JWA protein was a newly identified microtubule-associated protein (MAP), which combined to and co-localized with β-tubulin. In the present study, we designed a series of experiments to explore if any interactions between JWA protein and α-tubulin existed and how JWA protein would functionally link to α-tubulin, especially in cell mitosis. Results of coimmunoprecipitation, gene transfection and immunofluorescence microscopy from PC12 and HEK293 cells provided strong evidence for a linkage between JWA protein and α-tubulin. Our data showed that JWA protein bound to α-tubulin stably no matter whether α-tubulin was polymerized or not. In addition, by using antisense oligonucleotides, cell cycle blocking agents and hypothermia disposal techniques, we also found the interaction between JWA protein and α-tubulin. The further analysis using flow cytometry and confocal microscopy showed that both proteins co-existed in PC12 cells and were independent on the cell cycle. In conclusion, JWA protein is a newly identified microtubuleassociated protein, binds to α-tubulin, and probably plays an important role in regulation of microtubular stability. more...

Two real-time modeling prediction (RMP) schemes are presented in this paper for analyzing the behavior of deep excavations during construction. The first RMP scheme is developed from the traditional AR(p) model. The second is based on the simplified Elman-style recurrent neural networks. An on-line learning algorithm is introduced to describe the dynamic behavior of deep excavations. As a case study, in-situ measurements of an excavation were recorded and the measured data were used to verify the reliability of the two schemes. They proved to be both effective and convenient for predicting the behavior of deep excavations during construction. It is shown through the case study that the RMP scheme based on the neural network is more accurate than that based on the traditional AR(p) model. more...

Our previous studies demonstrated that JWA, a novel retinoic acids responsive and cytoskeleton related gene, is associated with cell differentiation and apoptosis. In the present study, to elucidate if the JWA is a novel kind of microtubule-associated proteins (MAPs) and functionally link to microtubule, we first successfully identified JWA from the physically purified MAPs complex of rat brain tissues. The results of co-immunoprecipitation, gene transfection and immunofluorescence microscopy assays from HBE and NIH3T3 cells provide strong evidence for a linkage between JWA and β-tubulin. In general, JWA is stably binding to β-tubulin whenever microtubule is polymerized or not, and it may be critical to the mitosis process. In addition, by use of the antisense oligonucleotides technique, we also showed that JWA is a negative modulator on intracellular amino acids in PC 12 cells. Further analysis indicated that JWA selectively regulates both taurine, an inhibitory amino acid, and glutamate, an excitatory amino acid. In conclusion, JWA is not only structurally associated, but also a novel functional MAP. more...

A damper device based on shape memory alloy (SMA) wires is developed for structural control implementation. The design procedures of the SMA damper are presented. As a case study, eight such SMA dampers are installed in a frame structure to verify the effectiveness of the damper devices. Experimental results show that vibration decay of the SMA damper controlled frame is much faster than that of the uncontrolled frame. The finite-element method is adopted to conduct the free and forced vibration analysis of the controlled and uncontrolled frame. The experimental and numerical results illustrate that the developed SMA dampers are very effective in reducing structural response and have great potential for use as efficient energy dissipation devices with the advantages of good control of force and no lifetime limits, etc. more...

A capillary gas chromatographic method was developed for determining 1-p-(3.3-dimethyl-1-triazeno) benzoic acid in the plasma and urine of cancer patients under pharmacokinetic study. The drug was extracted with ethyl acetate and methylated with diazomethane. Octadelane (10 µg/ml) was added as internal standard. The separation was carried out on an OV-1 quartz capillary column, 15 m × 0.32 mm (0.52 µm), with high-purity nitrogen as carrier gas and flame ionization detector (FID) as detector. The column temperature was held at 130°C for 9 min and then programed to 240°C, at a rate of 35°C/min. The temperature of both injector and detector was 260°C. The standard curve was linear from 0.4 to 40 µg/mL in plasma, and from 0.8 to 20 µg/mL in urine, with correlation coefficients of 0.9979 and 0.9932. The relative standard deviations (RSD) were less than 9.7%. The minimum recovery of this method was 81.8%. This method was applied to the pharmacokinetic studies of 1-p-(3.3-dimethyl-1-triazeno) benzoic acid in cancer patients after a single dose (i.v.) of 160, 420 or 760 mg/m2 was administered. They all conformed to the two-compartment open model and showed linear pharmacokinetics. The excretion of this drug in the urine was minimal. Copyright © 2001 John Wiley & Sons, Ltd. Abbreviations used: AUC area under the curve DTIC dacarbazine MTD maximum tolerance dosage P-COOH-DMT 1-p-(3.3-dimethyl-1-triazeno) benzoic acid RSD relative standard deviation. more...

To study how the combined effects of various differentiation inducers and heat stress on the expression of JWA protein in K562 cell, the relationship between JWA and Hsp70 expression, and the signal regulation mechanism possibly involved.The experimental model was established in K562 cells. Various directional differentiation inducers (TPA, Ara-C, hemin, adriamycin, ATRA and As(2)O(3)) were used alone or combined with heat shock treatment (42 degrees C, 2 h). Western blot was used for detecting expressions of JWA, Hsp70, heat stress factor 1 (HSF1) and HSF2.(1) The expressions of both JWA protein and Hsp70 were significantly up-regulated after K562 cells treated by TPA (100, 200 ng/ml) or adriamycin (4 x 10(-8) mol/L) 48 h, and followed by heat shock (42 degrees C, 2 h). However, the opposite effects were observed when the cells treated by hemin (3 x 10(-5) mol/L, 48 h), Ara-C (80 ng/ml, 48 h) and As(2)O(3) (1 x 10(-6) mol/L, 48 h) followed by 2 h heat shock. No obvious changes were found when the cells treated by ATRA (1 x 10(-6) mol/L, 48 h) alone or followed by heat shock. (2) Both the heat shock transcriptional factors HSF1 and HSF2 did not show any significant changes when K562 cells were treated with various differentiation inducers and followed by heat stress.JWA not only takes part in the regulation of K562 cellular differentiation, but also of heat stress, it might be the co-target gene of several differentiation inducers and heat stress. The expression of Hsp70 seems not mediated by both HSF1 and HSF2 in K562 cells undergoing directional differentiation or heat stress treatment. JWA is likely to be a new signal molecule similar to Hsp70 signal pathways. The results show that JWA takes part in the mechanism of K562 cell response to heat stress. more...

To study the expression of JWA protein and heat shock protein (Hsp70), and to explore these relationship and the possible mechanism of JWA gene involved in induced differentiation and heat stress (42 degrees C) of K562 cells.The models of differentiation and heat stress of K562 cells were established. Western blot was used for detecting expressed proteins of JWA gene, Hsp70, heat shock factor (HSF1 and HSF2).(1) Under the condition of differentiations induced by TPA (100 ng/ml), hemin (3 x 10(-5) mol/L), Ara-C (80 ng/ml), adriamycin (4 x 10(-8) mol/L), ATRA (1 x 10(-6) mol/L) and As(2)O(3) (1 x 10(-6) mol/L) for 48 h respectively, the expression of JWA protein and Hsp70 were more significantly increased than control; the level of HSF2 protein was increased by inductions of hemin, Ara-C and adriamycin, respectively. (2) After heat exposure to 42 degrees C for 10, 20, 30, 45, 60, 90 min, and heat exposure to 39 degrees C, 42 degrees C, 45 degrees C, the trend of changing in expression of Hsp70 was similar to that of JWA protein, and HSF1 was expressed in earlier stage.The expression of JWA protein and Hsp70 were upregulated in induced differentiation and in heat stress, and the change of expression of JWA protein were similar to that of Hsp70, but the intracellular transduction signal pathways involved may be various. JWA might not be specifically related with both HSF1 and HSF2. more...