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BACKGROUND The ongoing coronavirus disease 2019 (COVID-19) pandemic and the universal implementation of control measures are fundamentally affecting every aspect of our society and daily lives. AIM To evaluate the prevalence of post-traumatic stress disorder symptoms and their associated factors as well as the effects and attitudes towards online education in Chinese high school students. METHODS A total of 883 students were included. The first, second and third-year students of a high school in Lanzhou, Gansu province of China were invited to participate in this study. They were requested to involve their parents to complete the survey together. A detailed questionnaire of 65 questions was designed and divided into five sections. The survey was anonymously conducted via WeChat, a Chinese multipurpose messaging, social media and mobile payment app. RESULTS Overall, 32.94% of students experienced post-traumatic stress disorder due to the COVID-19 epidemic. The majority of students (60.82%) felt that online education was not (10.76%) or less effective (50.06%) in terms of gaining knowledge and improving practical and communications skills. Correlation analysis revealed that the class level, residential background and whether living with parents were significantly linked with the effectiveness and satisfaction of the online education system. Of the final year students, 74.2% said that the COVID-19 outbreak has negatively affected their preparation for the college entrance exam, and 68% of students felt that this outbreak increased psychological pressure for their college entrance examination preparation. In case of having COVID-19 symptoms during the exam, 50.7%, 13.3%, and 10.2% would notify the proctor, teacher and parents, respectively. CONCLUSION We found a high prevalence rate of post-traumatic stress disorder symptoms in high school students. Thus, our results call for urgent attention from both government and schools to implement effective interventions to cope with the psychological effects and the disturbance of education by COVID-19 on children.

The feasibility of monitoring the dipped rail joint defects has been theoretically investigated by simulating a locomotive-mounted acceleration system negotiating several types of dipped rail defects. Initially, a comprehensive locomotive-track model was developed using the multi-body dynamics approach. In this model, the locomotive car-body, bogie frames, wheelsets and driving motors are considered as rigid bodies; track modelling was also taken into account. A quantitative relationship between the characteristics (peak–peak values) of the axle box accelerations and the rail defects was determined through simulations. Therefore, the proposed approach, which combines defect analysis and comparisons with theoretical results, will enhance the ability for long-term monitoring and assessment of track systems and provides more informed preventative track maintenance strategies.

The rice stem borer

To study the dynamic performance of middle locomotives and their couplers of 20,000t heavy haul combined train under pressing coupler force, the longitudinal dynamic characteristics of train’s electric braking, cyclic braking and emergency braking on straight track were calculated with the longitudinal train dynamics (LTD) simulation package TDEAS, the coupler force of middle locomotives were obtained and sent to multi-body system (MBS) model of train established in package SIMPACK, and then the dynamic behaviour of middle locomotives and their couplers under pressing coupler force were studied. The results show that under the pressing force in straight track, the vertical dynamic performance of locomotive will be influenced in certain degree, the guiding wheelsets will upload while the rear wheelsets unload, the more the pressing force is, the greater the upload and unload will be. There is less influence on lateral dynamic under straight track condition.

Based on the technology of OpenGL and DirectX Wrapper, this paper designs and implements a new general method of data collection and display for the existing three-dimensional models using in multi-view 3D display system. Firstly, by using the technology of OpenGL/DirectX Wrapper, it obtains the application information such as the models, calls and associated data. Secondly, it sends the information to all rendering nodes. Then, according to the multi-view system projection array number and expected angle threshold parameter, each rendering node does the final adjustment and calibration on the obtained information sequentially for multi-view image rendering. Finally, each node transmits corresponding viewpoint image rendered by themselves to the projection equipment, and displays stereo images through 3D device synchronously. This method can be applied to all application programs based on OpenGL or DirectX Library. It is a general method for collecting and displaying multi-view 3D data sources. Experimental results show that this method is of high acquisition and rendering process, the image quality is the same as the source and stereoscopic displays strong. It has a wide range of applications and research value in the field of Engineering.

Well-crystalline flowerlike α-Bi2O3 hierarchical architectures with pineapple-shaped petals have been synthesized by precipitation method at a volume ratio of DMF/H2O of 5, where DMF and H2O were used to dissolve Bi(NO3)3 and KOH, respectively. If the DMF/H2O ratio was decreased to 2:1, 1:1 and 0:30, flower-, bundle- and dendrite-shaped α-Bi2O3 microcrystallites aggregated by nanorods were formed, respectively. The simple synthetic route and thus obtained Bi2O3 architectures of various morphologies provide a basis insight for their formation mechanism. The photocatalytic activity of the as-prepared Bi2O3 particles for degradation of Rhodamine B (RhB) under visible-light irradiation was obviously influenced by their morphologies. Bi2O3 of nanorod-based microstructures exhibited higher photodegradation activity than nanobrick-based ones, owing to higher light absorption and carrier separation efficiency in one-dimensional (1D) nanostructured materials.

Data stream in a popular research topic in big data era. There are many research results on data stream clustering domain. This paper firstly has a brief introduction to data stream methodologies, such as sampling, sliding windows, etc. Finally, it presents a survey on data streams clustering techniques.

The purification of polyether polyols with low unsaturation was studied. The removal effect of residual double metal cyanide in the polyols by the methods of adsorption and precipitation-filtration is characterized by the residual concentration of the zinc and cobalt ions which is measured by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). Compared with precipitation-filtration, the method of adsorption was more practical and efficient for the purification of the polyols. And the optimum kind and amount of the adsorbent were obtained. The results showed that the combination of chelating fiber and attapulgus clay was the most favorable for the removal of zinc and cobalt ions and the appropriate weight ratio of chelating fiber and attapulgus clay was 1:1. The total concentration of zinc and cobalt ions can be reduced to lower than 1×10-6. And the amount of the adsorbent added was 3.33% by the weight of the polyether polyols. And through Scanning Electron Spectroscopy (SEM) the morphology of the chelating fiber was characterized before and after adsorption.

Track irregularity is one of the most important aspects of the suspension control performance impact in maglev transportation system (MTS). Due to the track irregularity phenomenon of suspension system, the Fuzzy PID(F-PID) control is unable to accurately track irregularity of track changes. Based on the qualitative analysis to MTS, through modifying conventional F-PID controller, the article establishes Fuzzy Immune PID(FI-PID) Controller based on the biological immune system theory. The control strategy designed nonlinear P controller, using the immune algorithm of on-line adjustment of P and the fuzzy control approximating the nonlinear function of the immune P control parameters and the fuzzy control designed the ID controller for adjusting the parameters of I and D for enhancing the robust performance of the suspension system and adapting to the change of track irregularity. Simulation results show that the FI-PID control is confirmed more effectively to realize tracking compared with F-PID, faster response speed, more simple structure, easier operation for the track interference and load disturbance of the suspension system. This provides a very good way to solve the interference problem of orbit of the maglev transportation system.

Track irregularity is one of the most important aspects of the suspension control performance impact in Magnetic Transportation System (MTS). By using the traditional PID control, the problem was that it was difficult to confirm the PID parameters and have long settling time, even appear the chaotic phenomenon. However, using Expert PID(EPID) control method producesd over-fitting to initial assignments, local optimum induced easily and slow convergence rate problem. Based on the global optimization feature of PSO algorithm, it had been adopted to optimize the initial values of Expert PID control. An intelligent control algorithm for the maglev transportation system was put forward based on Expert PID optimized by Particle Swarm Optimization algorithm (EPID-PSO). The expert rule was that if the absolute value of the error trended to decrease, the PID current control keeped its maintenance; if not, then the PID current control applied strong functions. Under this rule, the dynamic error was reduced and the performance of track irregularity was improved. Simulation results by MATLAB proves that the control scheme has good robustness, shorter adjustment time, faster response time, achieving better quality of control under the three conditions of step signal, low frequence sine wave signal and high frequence square wave signal.

Computer network is an advanced platform of communication transmission, in which the different transmission modes such as point-to-point and point-to-multipoint can be implemented by relying on the wide coverage scope of the Internet. In this paper, the functions (e.g. data processing, signal transmission, and comprehensive control) of network communication are firstly introduced, and then the digitalized transformation trend of computer network communication system is analyzed, and finally the comprehensive measures for the construction of new communication system are proposed. Hopefully, this paper can play a help in the further studies.

Because of the large span of the distance between wireless communication networks, many kinds of interference are encountered in the network signal transmission process, so that the accuracy of receiving the information is affected by the weakened signals and also the communication service quality for the users is reduced. Under this background, the advantages such as remoteness and convenience of wireless communication are first introduced. In the meantime, the factors influencing the signals of the wireless communication network are affected. Finally, the measures for enhancing the signals of the wireless communication network sites are proposed. It is expected that this paper is helpful for the future studies.

The effectiveness of path planning and path replanning for intelligent robot using improved ant colony algorithm is explored in this paper. For the purpose of avoiding falling into local optimum and preventing iterative stagnant, this paper describes a new algorithm named stochastic self-adaptive ant colony algorithm to improve the basic ant colony algorithm. Based on the improved ant colony algorithm, the approaches of path planning and path replanning are presented in this paper. Aiming at improving the speed of the algorithm and simplifying the objective function of traditional path planning, this paper presents a principle of eliminating the path nodes .Finally, some constrast emulators are designed.The simulation results proves that the improved ant colony algorithm has strong adaptability in intelligent robots path path planning and replanning.

The striped stem borer (SSB), Chilo suppressalis (Walker) (Lepidoptera: Pyralidae), is a major pest of rice in China. Variation in host-plant quality may affect the body size of herbivorous insects, which in turn, can determine their life-history parameters such as survival, fecundity and fitness. In this study, we tested the effects of high-quality aromatic rice varieties on the fitness of SSB in China. Results showed that 1st instar larvae had higher penetrating rates and survival rates on the high-quality aromatic rice varieties (EX-1 and WX-988) than that on the non-aromatic rice varieties (EZ-5 and LYP-9). In addition, shorter developmental periods, greater female pupal weights and higher of other life-history parameters (hatching rate, pupation rate, eclosion rate and increase index) were found on the high-quality aromatic rice varieties, although only female pupal weight showed a significant difference between the two varieties. The highest dead heart rate was found on the aromatic rice variety of EX-1. These results indicate that SSB sustains a lower fitness cost when consuming the high-quality aromatic rice varieties (EX-1 and WX-988) than on the non-aromatic rice varieties (EZ-5 and LYP-9) in Central China.

General Purpose Polystyrene (GPPS) and High Impact Polystyrene (HIPS) were foamed with supercritical carbon dioxide in the batch foaming process. Foaming behaviors of GPPS and HIPS were investigated. The cell diameters and cell densities of GPPS and HIPS vary strangely with foaming conditions and can be explained by the classical nucleation. The competition between cell growth and cell nucleation is used to explain these strange foaming behaviors. The glass transition temperature (Tg) almost remains constant with the foaming temperature rising.

Nowadays computer systems face the risk of being plagued by powerful, feature-rich malware. Current malwares exploit the vulnerabilities that are endemic to the huge computing base that needs to be trusted to secure our private information. This summary presents the trusted computing base (TCB) and the Trusted Computing Group (TCG). There are extensive theories about information security and technology. In this paper, we provide some technologies and methods in order to help prevent application systems from being attacked by malware and controlled by unauthorized persons. Finally, we introduce efficient TCB reduction.

Aiming at accurate predictions of coupler/daft gear systems' dynamic behaviour. Based on the analysis of structural and kinematic relations of two typical systems, hysteretic nonlinear draft gear models and 9DOF (Degree of freedom) detailed coupler/draft gear system models were developed. Frictional pairs on coupling surfaces and coupler tails along with interactive aligning shoulder models were integrated into system models. Utilizing two detailed locomotive models simulations were performed on a section of special track to validate the rationalities of coupler/draft gear system models. Simulation results indicate that all parts in coupler/draft gear system models can fullfill their roles, and the system models themselves can reproduce the run-time behaviour of coupler/draft gear systems with high reliability and accuracy.

Two types of typical heavy-haul locomotive coupler models were presented, one is round-pin coupler with shoulder-limit, and another is flat-pin coupler with frictional tail pairs and stop-limit, both of them adapting nonlinear hysteresis buffer models. Utilizing a train model consists of 2 detailed locomotives and 1 simplified freight wagon, curving behaviour of different couplers were studied. The results show that, the actual curving behaviour of different couplers could be accurately simulated by the established coupler dynamics models. This paper will play a promoting role for analyzing actual heavy-haul locomotive running behaviours and safety.

Numerical simulate analyze a super-long steel plant with ANSYS,calculate the structure in expansion joint,without expansion joint and without long circle bore structure of these three kind situations,analyze temperature stress and vertical displacement of the main component when the temperature changes.Setting expansion joint can control the temperature stress in a small range,which is a widely used method at present.However,not setting expansion joint and the use of long hole structure connection can control the size of the temperature stress and ensure the structure globality,it can provide design basis of this method in engineering applications.

Three series compressive tests of concrete columns, CFRP constraint concrete columns and CFRP constraint concrete columns under compression are carried out to study the influence of initial stresses on strengthening effect. Through comparing the data of experiments, initial stresses’ influence on stress peak of 2 times compressive specimens is analyzed and the calculating formula of peak stress is proposed considering the pre-compression ratio, aiming at providing experimental dependences for strengthening design.

Compressive tests of 30 concrete column specimens with three concrete strength grades are carried out in this paper to study ultimate compressive strength of specimens. The specimens are divided into three groups, that is, unconfined, confined by CFRP with no initial compression and confined by CFRP with various initial compressions. The different initial compressions’ influence on ultimate stresses and strains are investigated. The decrease of CFRP reinforcing effect due to pre-compression are analyzed. The research results provide experimental datum for reinforced design of existing concrete columns.

Purification of polyether polyols made by double metal cyanide catalysis was studied. The removal effect of residual double metal cyanide in the polyols by the methods of adsorption and precipitation-filtration is characterized by the residual concentration of the zinc and cobalt ions which is measured by Inductively Coupled Plasma Atomic Emission Spectrometry. Compared with precipitation-filtration, the method of adsorption was more practical and efficient for the purification of the polyols. And the optimum kind and amount of the adsorbent were obtained. The results showed that the combination of chelating fiber and attapulgus clay was the most favorable for the removal of zinc and cobalt ions and the appropriate weight ratio of chelating fiber and attapulgus clay was 1:1. The total concentration of zinc and cobalt ions can be reduced to lower than 1×10-6. And the amount of the adsorbent added was 3.33% by the weight of the polyether polyols. Also through Scanning Electron Spectroscopy the morphology of the chelating fiber was characterized before and after adsorption. The functional groups on the surface of the fiber could be coordinated with the catalyst attached to the polyol polymer chains to form the separable insoluble particles.

Transgenic Bt rice has been shown to be an effective means of controlling Lepidoptera pests of rice. However, the potential roles of transgenic rice on planthoppers and their predators need to be investigated before its commercialization. Population density, species dominance and population dynamics are important parameters of arthropods populations in field. So the impacts of three transgenic Bt rice strains expressing cry1Ab/cry1Ac, cry1C and cry2A on population density, species dominance and population dynamics of three species of planthoppers (Nilaparvata lugens, Sogatella furcifera and Laodelphax striatellus) and their three main predators (Cyrtorhinus lividipennis, Pirata subpiraticus and Theridium octomaculatum) were evaluated at three sites in Hubei Province, China, in the current study. The results showed that among three species of planthoppers, both in transgenic and non-transgenic rice field, the predominant species of planthoppers within phytophagous guild was S. furcifera at any site either growing season (46–50%). Significantly higher population density of N. lugens was observed in T2A-1 field relative to Minghui 63 field at Wuxue in 2010. The species dominance of predator, P. subpiraticus, in TT51 field was significantly higher than that in T1C-19 and T2A-1 fields in 2009 at Xiaogan site. Sampling date significantly influenced six arthropods except for P. subpiraticus in 2010. The interaction between rice strain×sampling date had no significant adverse effects on the population dynamics of three species of planthoppers and their predators, except for several individual species in 2009. The interaction among rice strain×sampling date×sampling site also had no significant effect on six arthropods except for S. furcifera in 2009. The results indicated that transgenic Bt rice expressing cry1Ab/cry1Ac, cry2A and cry1C had no significant adverse effects on the population dynamics of three planthoppers and their predators in most investigated data and sampling site.

Utilizing CFD, the influences of skirt board structure on high speed maglev train's aerodynamic resistance and the stability under crosswind are studied. Studies have been conducted on the aerodynamic of skirt boards which located on different positions. Simulation analyses are finished with maglev train running at speed of 350km/h for both with and without crosswind. Study results show that, some skirt boards are likely to be pulled apart, further, lower the safety limit speed.

Dynamic compaction method was widely used in various engineering foundation reinforcement, the research of influence to surrounding environment from dynamic compaction and the measures of reducing vibration was not complete. In this paper, the decay laws of dynamic compaction vibration acceleration in horizontal direction was got through the model test, the attenuation formula of horizontal vibration acceleration was fitted, which provides theory basis for determining the influence scope of dynamic compaction; And the depth and filling materials two influence factors of vibration isolation ditch were researched by model tests, which provide important basises for the application of vibration isolation ditch.

To study the experimental method of axial compressive test of concrete columns in service strengthened with bonding FRP(fiber reinforced plastic), the post-tensioned pre-stressing method was employed to exert initial stress to the specimens before bonding FRP, Then FRP was bonded. Axial loading method of the specimens was that one main jack exerted axial force and two jacks provided stiffness for the specimens. In this way the complete stress-strain curves of specimens was obtained. The results indicated the technical target of axial compressive test of in service concrete columns strengthened with FRP was greatly achieved by using this experimental method.

Aimed to wheel flange partial wear problem, the heavy haul train dynamic model was setup, and the coupler and buffer system was setup in detail. The dynamic performance of the train under the longitudinal coupler press force was simulated. The wheel/rail lateral force and wheel flange wear were analyses. Simulation results shown that the front locomotive will suffer a big longitudinal press force for the delay of the brake force transfer; this will lead the rotation of the coupler. The lateral force will apply to the car body at the position of coupler, which was caused by the longitudinal coupler force and the rotation angle of the coupler, then the wheel flange partial wear were induced as a result.

The invasive, insecticide-resistant, Q whitefly biotype, has gradually spread to other countries including the US via human-mediated movement of plant materials. We assessed the utility of the VspI-based mtCOI (mitochondrion cytochrome oxidase I) polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) tech- nique as a rapid, cost-effective, and reliable alternative for differentiating the Q from the dominant B biotype in Arizona. Using the standard mtCOI gene sequencing and mtCOI PCR-RFLP techniques, we biotyped eight whitefly strains of five individuals each collected from poinsettia and cotton at different locations in Arizona. Complete concordance was observed between the two methods, with three strains being identified as the Q biotype and five samples as the B biotype. We also scanned the mtCOI gene sequences for VspI polymorphisms in the B and Q biotype whiteflies currently available in the GenBank database. This global screening revealed the existence of three and four VspI polymorphic types for the Q and B biotypes, respectively. Nevertheless, all three VspI polymorphic Q biotype whiteflies shared a common and unique VspI site that can be used to differentiate Q biotype from the four VspI polymorphic B biotype whiteflies identified. These results demonstrate that the VspI-based mtCOI gene PCR-RFLP provides a reliable diagnostic tool for differentiating the Q and B biotype whiteflies in the US and elsewhere.

Although long-term follow-up after sirolimus-eluting stent implantation shows a sustained clinical benefit in several randomized and registered trials, little is known about the pattern of neointimal growth beyond the first 6 to 9 months. In this study, we therefore evaluated the possible delayed restenosis in patients with coronary artery disease treated with sirolimus-eluting stent.A total of consecutive 333 patients with 453 lesions were enrolled in this study (among 782 consecutive patients with 1023 lesions). Lesions were subjected to follow-up by quantitative coronary angiography, and patients were divided into two groups according to the time of follow-up by quantitative coronary angiography: early group (or =270 days, n=270 with 369 lesions) and late group (270 days, n=63 with 84 lesions). Binary restenosis was defined as stenosis of more than 50% of the lumen diameter in the target lesion.Baseline clinical, demographic or angiographic characteristics were well balanced between the two groups. The in-stent restenosis rate was not significant between the early group and the late group (3.5 vs. 6.0%; P0.05). The late loss and target lesion revascularization appeared higher in late group but there were no significant differences (0.15+/-0.38 mm vs. 0.24+/-0.44 mm; and 4.9 vs. 9.5%, P0.05, respectively). Similarly, overall thrombosis rate was also same in both groups. In-segment restenosis was, however, higher in late group compared with that in early group (7.9 vs. 16.7%, P=0.013).In this unrestricted population, the beneficial effects of sirolimus-eluting stent implantation extend out more than 1 year in real world practice, that has been confirmed by the results of the large randomized clinical trials. The late in-segment restenosis could, however, be found, suggesting that a prolonged clinical and angiographic surveillance in this subset of patients seems to be warranted.

BACKGROUND Patients with small coronary lesions are at increased risk for repeat interventions after coronary angioplasty and stenting. The efficacy of drug-eluting stents (DES) has been demonstrated to improve the outcomes of these patients and is a focus of interest. Currently, two platforms of DES are available (sirolimus-eluting stent (SES) and paclitaxel-eluting stent (PES)). However, it has less been known that DES, SES vs PES, is superior for the treatment of small coronary lesions. METHODS In this retrospective study, 87 consecutive patients with 151 lesions underwent implantation of coronary SES (n = 68) and PES (n = 83). Quantitative coronary angiography (QCA) was performed at the time of stent implantation and subsequently at 8 months post-stenting. Small vessel disease was defined as lesions in vessels with diameter 2.5 mm measured by QCA. Major adverse cardiac events (MACE) including death, thrombosis, nonfatal myocardial infarction and target lesion revascularization (TLR) were compared between the two groups. RESULTS Baseline clinical characteristics and angiographic parameters were similar between the two groups. At clinical and angiographic follow-up, overall thrombosis rates were similar in both groups (0 vs 1.2%, P > 0.05). The TLR and in-segment restenosis were not significantly different (19.1% vs 25.3%; 10.3% vs 10.8%, P = 0.365 and P = 0.913 respectively) between the two groups. The in-stent restenosis rate, however, was significantly higher in the PES group (4.4% vs 21.7%; P = 0.002). Similarly, the late loss was significantly higher in the PES group ((0.140.38) mm vs (0.490.61) mm; P < 0.001). CONCLUSIONS In this small sample-size, non-randomized study, the data indicated that implantation of SES for the treatment of patients with small coronary lesion showed more favorable results in respect of restenosis compared with PES implantation.

BACKGROUND Several clinical trials have shown that rapamycin-eluting stents significantly reduce the risk of restenosis after percutaneous coronary intervention (PCI). The Firebird stent and the Excel stent (coated with bioabsorbable polymer) are two different types of rapamycin-eluting stents made in China, both have been recently approved for clinical use in China by State Food and Drug Administration. However, it is unclear whether there are differences in safety and efficacy between the two types of stents in daily practice. METHODS In the month of June 2006, a total of 190 consecutive patients were treated exclusively with Firebird stents (n = 93, Firebird group) or Excel stents (n = 97, Excel group) in our center and were included in this study. The frequency of major adverse cardiac events (MACE, a composite of death, myocardial infarction or target lesion revascularization), binary restenosis, and late lumen loss and stent thrombosis during a six-month follow-up period were compared between the two groups. RESULTS Patient and lesion characteristics were comparable between the groups. Major adverse cardiac event rates were low in hospital and at 6 months (2.1% in the Excel group and 0% in the Firebird group, P > 0.05). The 6-month angiographic in-stent restenosis rate was 0% in both groups, with an associated late loss of (0.15 +/- 0.21) mm versus (0.14 +/- 0.20) mm (P = 0.858) and the in-segment restenosis rate was also 0% for the Excel group and the Firebird group. There was no definite stent thrombosis identified in either group during the six-month follow-up period and only one patient in the Excel group had probable stent thrombosis in hospital. CONCLUSIONS Results from this mid-term, single-center study showed that both of the Firebird and the Excel rapamycin eluting stent had similar effects on reducing the incidence of MACE and the risk of restenosis (both in-stent and in-segment binary restenosis) after PCI in daily practice.

Background In-stent restenosis (ISR) remains a challenge for interventional cardiologists. Some data suggest that drug-eluting stents (DES) represent a promising new option for the treatment of patients with ISR. Currently, 2 DES platforms are available [sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES) ], but the superiority of either approach for treating ISR has not been convincingly demonstrated. The aim of the present study was to retrospectively compare angiographic and clinical outcomes after treatment of ISR with SES or PES in a series of consecutive patients with ISR. Methods A total of 745 consecutive patients were treated with bare metal stents from April 12, 2004 to December 31, 2004 in our center. Of these, clinically driven target lesion revascularization (TLR) was performed in 54 ISR from 54 patients at 7 months. Of the 54 patients with ISR, 36 received SES and 18 received PES. Follow-up included angiography and assessment of clinical outcome, both performed 7 months after DES implantation. Results There were no significant differences in baseline clinical data (including medication usage and lesion characteristics) between the two groups. Except for overlapping of multiple stents, procedural parameters were also similar in both groups. Seven-month angiographic follow-up showed that the binary restenosis rate was higher in patients treated with PES than that in patients treated with SES (in-stent binary restenosis: 27.8% vs 5.6%, P0.023; In-segment binary restenosis: 44.4% vs 13.9%, P0.014). Major adverse cardiac events (MACE) occuring during hospitalization or during the follow-up period including thrombosis and TLR was similar in both groups (22.2% vs 8.3%, P0.05). Conclusions Results from this small sample size, retrospective, single-center study showed that SES might be superior to PES in treating ISR because of lower 7-month restenosis rates (both in-stent and in-segment binary restenosis) with no increased incidence of MACE.

BACKGROUND: Stents are widely used in China but the clinical impression is somehow that restenosis is less common because of the lower prevalence of coronary artery disease (CAD) and associated risk factors in Chinese populations. However, no large-sample published studies are available on angiographic stent restenosis including those of bare-metal stent (BMS) or drug-eluting stent (DES) in Chinese Han ethnic population. METHODS: A total of 1633 consecutive patients with CAD who had undergone coronary stenting, quantitative coronary angiography (QCA) were retrospectively studied. At the time of stent implantation and at 7 months post-stenting 675 patients had a follow-up angiography. Statistical analysis was made with the chi-square test for categorical variables, unpaired t test for continuous variables, univariate or multivariate regression for baseline and angiographic characteristics and the Kaplan-Meier method for rate of target lesion revascularization (TLR). RESULTS: Stent restenosis was defined as > or = 50% diameter stenosis in the dilated segment. A total of 675 patients with 1074 lesions were subjected to angiographic follow-up for 7 months on average. Of these lesions, 448 were implanted with BMS whereas 626 lesions with DES. At 7 months, bare-metal in-stent restenosis occurred in 148 lesions (33.0%), and bare metal in-segment restenosis in 155 lesions (34.6%) in contrast to drug-eluting in-stent restenosis in 48 lesions (7.7%) and drug-eluting in-segment restenosis in 73 lesions (11.7%) (P < 0.001 compared with BMS respectively). Late loss in both in-stent and in segment was higher in BMS than in DES groups [(1.00 +/- 0.69) vs (0.28 +/- 0.52); (0.78 +/- 0.71) vs (0.21 +/- 0.52), P < 0.001 respectively]. Angulated lesion, lesion length, pre-procedural minimal luminal diameter (MLD), and BMS were independent predictors for TLR, (P < 0.01 respectively), whereas current smoker, ostial lesion, and stent overlapping, post-procedure in-stent MLD, lesion length, and stent types were independent predictors for in-segment restenosis (P < 0.01 respectively). Standard coronary risk factors such as hypertension, hyperlipidemia, diabetes, and history of CAD were not associated with a higher rate of restenosis caused by BMS or DES implantation in our Chinese Han ethnic population. CONCLUSIONS: Coronary stenting including BMS or DES implantation in Chinese Han ethnic patients is associated with a restenosis rate comparable to that demonstrated in previous studies from the western countries, and predictors of stent restenosis are somehow different from those in the western population.

BACKGROUND Drug-eluting stent (DES) could obviously reduce in-stent restenosis, which has been proved by international multi-center clinical trials. However, the types of the lesions for stenting were highly selected in these trials. Up to now, there has been no large scale study on the effect of DES in treating complex lesions in real world. Although REALITY trial was just reported during American College of Cardiology Congress 2005, the entry criteria for lesions were limited to one or two de novo lesions. This study was conducted to compare the short- and mid-term clinical outcomes between sirolimus-eluting stent (CYPHER stent) and paclitaxel-eluting stent (TAXUS stent) in patients with complex lesion. METHODS This is a retrospective study. From April 2002 to June 2004, a total of 1061 patients were treated with DES in Fu Wai Hospital, of which, 611 patients (642 lesions with 698 CYPHER stents) were in CYPHER group, and 450 patients (534 lesions with 600 TAXUS stents) were in TAXUS group. There was no significant difference in clinical data and lesion types between CYPHER group and TAXUS group. RESULTS Success rates of stent implantation were 99.2% and 98.8% in CYPHER and TAXUS stent groups respectively. The major adverse cardiac events (MACE) during in-hospital and 6-8-month follow-up were 0.7% and 2.3% in CYPHER stent group versus 1.3% and 3.2% in TAXUS stent group. There was no significant difference in MACE rate between these two groups. Restenosis rate was a little higher in TAXUS stent group than that in CYPHER stent group (14.0% vs 7.3%), but there was no significant difference. The incidence of acute occlusion of side branch after implanting DES in main vessel was 6.9% in CYPHER group and 11.9% in TAXUS group (P < 0.05). CONCLUSIONS CYPHER and TAXUS DES were safe and effective in patients with complex lesion. Clinical outcomes of CYPHER stent were better than TAXUS stent in bifurcation lesions. There was an increasing tendency in restenosis rate and late thrombosis in TAXUS group as compared with that of CYPHER group.

RNA interference (RNAi) suppresses the expression of target genes by post-transcriptional regulation. Because double-stranded RNA (dsRNA) mediated gene silencing is a conserved mechanism in many eukaryotes, RNAi has become a valuable tool for unveiling gene function in many model insects. Recent research has also shown that RNAi can also be effective in the downregulation of target genes in Hemiptera. In this review, we discuss the use of the RNAi technique in gene functional analysis in hemipterans, highlighting the methods of dsRNA uptake by these insects and discuss the knock-down efficiency of these techniques. Although the RNAi technique has disadvantages, our primary goal here is to determine whether it can be exploited further in the discovery of new gene functions, and as a pest control strategy, in some important Hemipteran pests.

Although the role of C-reactive protein (CRP) in predicting rapid progression of atherosclerotic lesions has been intensively studied in unstable coronary artery disease, the data from patients with stable angina (SA) are largely absent. The present study evaluated a middle-size patient cohort who underwent percutaneous coronary intervention (PCI) with stent implantation and follow-up coronary angiography (CAG) and tested the hypothesis that increased plasma level of high-sensitive CRP would indicate rapid progression of de novo non-target coronary artery lesions in Chinese patients with SA.The study population comprised of 311 consecutive patients with chronic SA who underwent coronary stent implantation on initial admission and angiographic follow-up ((8.5 ± 1.2) months). Rapid angiographic progression of non-target lesion was angiographically assessed and the patients were classified into two groups according to whether the progression existed or not. The relation of plasma CRP levels to the progression of atherosclerosis was investigated.Baseline demographic, clinical, and angiographic data were similar in patients with and without progression. Rapid angiographic progression of non-target lesions occurred in 136 patients (43.7%) at follow-up: 77 had a ≥ 10% diameter reduction of pre-existing stenosis ≥ 50%, 26 had a ≥ 30% diameter reduction of a pre-existing stenosis50%, 64 developed a new lesion ≥ 30% in a previously normal segment, and 4 had progression of a lesion to total occlusion. Progression of non-target lesions was not associated with target lesion restenosis formation. High-sensitive CRP levels were markedly higher in progression patients than in non-progression ones (1.60 (0.80 - 3.46) mg/L vs. 0.96 (0.55 - 1.87) mg/L, P0.001). Multivariate regression analysis showed that plasma CRP independently predicted rapid angiographic progression of non-target lesions (P = 0.001). High-sensitive CRP levels above 1.32 mg/L (the cutoff value) were associated with a 3.5-fold increase in the risk of developing rapid atherosclerotic progression (OR = 3.497, 95%CI 2.045 - 5.980).The data confirmed and extended previous studies that plasma CRP might independently predict non-target lesion progression in patients with SA after stent implantation.