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This study provides the discovery and validation of intervertebral disc degeneration (IDD) specific mRNA transcriptome profiles generated by NGS. We identified that insulin-like growth factor binding protein 5 (IGFBP5) was downregulated in human degenerative nucleus pulposus tissues and that its level was associated with the disc degeneration grade. In addition, the inhibitory effects of downregulated IGFBP5 are, in part, mediated through the ERK signaling pathway. Using in vivo and in vitro studies, functional characterization of the role of IGFBP5 revealed that the loss of its expression is an event in IDD pathogenesis. Therefore, strategies to maintain the expression or to prevent the repression of IGFBP5 have the potential to become a possible therapeutic and/or preventive approach for degenerative disc disease.

In 3D video transmission, the user Quality of Experience (QoE) can be greatly affected by network congestion or packet errors. In case of durable impairment within a view, the user-end could skip its impaired frames, or compensate its frames from the other view, or degrade its image resolution to ensure playback continuity. These operations have the inevitable leverage to Frame Loss (FL), Frame Compensation (FC) and Quality Fluctuation (QF). In this work, we compare the monocular and binocular impacts of FL, FC and QF on the user QoE of 3D High Definition (HD) videos. Among them, the QF is shown to be the preferable choice for subjects. We hope our findings could benefit the improvement of 3D HD video transmission.

OBJECTIVEAs scoliosis in arthrogryposis multiplex congenita (AMC) is unusual and the number of cases reviewed in previous studies is also relatively small, no previous study exists that has directly compared the results of spinal deformity correction between AMC and adolescent idiopathic scoliosis (AIS) patients. The aim of this study was to compare the radiographic and clinical outcomes of surgical correction of spinal deformity associated with AMC versus AIS.METHODSTwenty-four adolescents with AMC were matched with 48 AIS patients in terms of Cobb angle of main curve, curve pattern, sex, age at surgery, Risser grade, and length of follow-up. Patients in both groups underwent posterior-only spinal correction and fusion procedures. The surgical outcomes and complications were analyzed and compared between the 2 groups.RESULTSIn comparison to the AIS group, the AMC group had a significantly longer mean operation time (5.6 vs 4.4 hours, p = 0.002), more blood loss (1620 ± 250 ml vs 840 ± 260 ml, p < 0.001), and more fusion levels (14.1 ± 2.3 levels vs 12.4 ± 2.5 levels, p = 0.007) as well as a lower correction rate (44.3% ± 11.1% vs 70.8% ± 12.4%, p < 0.001) and a higher rate of loss of correction (5.0% ± 3.1% vs 2.1% ± 1.9%, p < 0.001). Nine patients in the AMC group had preoperative pelvic obliquity, which was corrected from a mean of 14.2° ± 8.4° to a mean of 4.3° ± 3.2° (p < 0.001) after the surgery. The thoracic lordosis and sagittal vertical axis were significantly improved in the AMC group. Notably, however, the AMC group was found to have higher rates of screw malpositioning (15.9% vs 9.5%, p = 0.002) and complications (8/24 [33.3%] vs 4/48 [8.3%], p = 0.016) as compared to the AIS group.CONCLUSIONSCorrection of AMC-associated scoliosis tends to require a longer operating time and involve more fusion levels but results in less correction, more blood loss, and more complications, in comparison with AIS. In addition, more attention should be paid to pelvic obliquity and sagittal hyperlordosis in AMC patients.

In this paper, the problem of fast time-varying channel prediction is investigated in high-speed railway communication systems. A channel prediction algorithm is proposed based on a support vector machine (SVM) model. In order to further improve the prediction accuracy, the penalty coefficient and Gaussian kernel width of the SVM model are optimized by a genetic algorithm (GA). Simulation results show that the proposed prediction model based on both the SVM and the GA (SVM-GA) has lower prediction error than traditional auto-regressive (AR) and single SVM prediction models. In addition, when the effect of the noise on prediction performance is considered, the SVM-GA prediction model is superior to the AR and the SVM models in terms of normalized mean squared error.

Background Clinical and radiographic degenerative spondylolisthesis (CARDS) classification defines a distinct subset of patients with kyphotic angulation at the involved segment (type D). Research using CARDS classification to investigate motion characteristics at involved segments or patient-related outcomes (PROs) following surgical intervention is sparse. We investigated the relationship between CARDS type D spondylolisthesis and dynamic instability and PROs in type D versus non–type D spondylolisthesis. Methods We reviewed consecutive patients who received transforaminal lumbar interbody fusion for L4-5 spondylolisthesis between 2009 and 2015. Patients were assigned into type D and non–type D groups. Translational motion was determined by upright lumbar lateral radiography with supine sagittal magnetic resonance imaging or flexion and extension radiography. Demographics, radiographic parameters, and PROs were evaluated. Results Type D and non–type D groups comprised 34 and 163 patients, respectively. Compared with non–type D, type D group was characterized by lordotic angulation loss and higher degree of olisthesis on upright radiographs and demonstrated higher translational motion on upright lumbar lateral radiography with supine sagittal magnetic resonance imaging analysis. After surgery, mean reduction rate was significantly higher in type D group; type D had less slippage, but differences in slip angle and disc height were not significant. Preoperative Oswestry Disability Index and visual analog scale for back pain scores were higher in type D group. Type D spondylolisthesis and dynamic instability were associated with achieving minimal clinically important differences in PROs. Conclusions CARDS type D spondylolisthesis is a distinct subset associated with dynamic instability and worse PROs. Higher improvement in PROs can be achieved in CARDS type D spondylolisthesis after surgery.

Surface stiffness is considered a key parameter for designing high-performance implantable materials and artificial extracellular matrices because of its substantial effects on cell behavior. How to transform biomolecule recognition events, particularly chiral recognition, into stiffness change on material surfaces is biologically essential but very challenging for chemists. Here, we report a chirality-triggered stiffness transition on a smart polymer film, which consists of flexible polyethylenimine (PEI) main chains grafted with dipeptide units capable of discriminating chiral monosaccharides. The polymer film became substantially softer after interacting with L-ribose and became more rigid after interacting with D-ribose (the basic building block of DNA and RNA). This chiral effect provides a new method for determining the enantiomeric purity of an L/D-ribose mixture and facilitates the chiral separation of deoxyribose racemates as well as the separation of diverse mono-, di-, and oligosaccharides. These are three puzzle problems in carbohydrate chemistry. Furthermore, taking advantage of the significant differences in the surface stiffness, the proliferation of fibroblast cells on the polymeric surfaces can also be regulated by chiral biomolecules.

Admission control in high-speed train communication system is quite different from admission control in traditional cellular networks. Conventional admission control strategies cannot be directly applied to this special communication scenario. In this paper, the problem of admission control for handover service is investigated in high-speed train communication environment. An admission control scheme considering bit error rate (BER) and bandwidth borrowing strategy is proposed. On the basis of admission control decision rule taking BER into account, a part of bandwidth obtained by compressing variable rate service in the networks is provided for handover services. The admission control scheme can admit handover services as more as possible while it guarantees the lowest data rate of different services in the networks. Simulation results show that the proposed admission control scheme has a better performance than existing admission control schemes.

Hollow poly(cyclotriphosphazene-co-phloroglucinol) (PCPP) microspheres, synthesized by a facile precipitation polymerization method and then a simple solvent-treatment procedure, were evaluated as a potential adsorbent for the removal of cationic dyes from aqueous solution. The adsorbent was characterized by SEM, TEM, FTIR, N 2 adsorption/desorption isotherms, zeta potential and particle size analysis. The adsorption process with respect to operating parameters was investigated to evaluate the adsorption characteristics of the hollow PCCP microspheres for methylene blue (MB). Systematic research including equilibrium, kinetics and thermodynamic studies were performed. The results showed the hollow PCCP microsphere was a potential adsorbent with an adsorption capacity of 50.7 mg/g at 298 K. The adsorption behavior followed the pseudo-second-order kinetic model and the adsorption equilibrium data obeyed the Langmuir isotherm well. Thermodynamic analyses confirmed that the adsorption was a physisorption process with endothermic, spontaneous and random characteristics. In addition, the possible adsorption mechanism was also proposed based on the experimental results. The study of selective adsorption further indicated the hollow PCCP microspheres could also remove other cationic dyes efficiently and be used a selective adsorbent.

Polyaniline (PAni) hydrogel was synthesized in a facial method by using phytic acid as both dopant and cross-linking agent. Then the fabricated hydrogel was employed as an efficient adsorbent to remove the methylene blue (MB) in an aqueous solution. The as-synthesized PAni hydrogel was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images. The characterization results indicate that the obtained PAni hydrogel has a 3D structure, which is available for the contact between the adsorbent and dye molecules. During the adsorption, the phytic acid provides a large number of anionic phosphate groups as adsorption sites for MB molecules, which induces the high adsorption capacity up to 71.2 mg/g. The effects of pH, the PAni hydrogel mass and temperatures on adsorption efficiency were studied in details. Further experimental results indicate the adsorption kinetic fits well with the pseudo-second-order kinetic model. Compared with Freundlich model, Langmuir isotherm model was more acceptable to fit the equilibrium adsorption data. Moreover, the conceivable mechanism of the adsorption was also proposed in this work.

The polypyrrole (PPy) nanofibers were synthesized by an oxidative template assembly route and evaluated as an adsorbent for the removal of a typical anionic dye (methyl orange, MO) from aqueous solution. The as-synthesized PPy nanofibers were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and N 2 sorption. The effects of contact time, initial MO concentration, temperature, and initial solution pH on the adsorption of MO onto PPy nanofibers have been investigated. Experimental results showed that the PPy nanofibers possessed excellent adsorption capacity for MO (169.55 mg/g) at 25 °C. The pseudo-second-order model could fit to the experimental data better comparing with the pseudo-first-order kinetic adsorption model. And isotherm data fitted well to the Langmuir isotherm model. Thermodynamic study revealed that the adsorption process was endothermic and spontaneous in nature. In addition, the possible adsorption mechanism was proposed based on the experimental results. And the selective adsorption behaviors of the polypyrrole nanofibers towards different organic dyes were explored and the re-use of adsorbate was tested.

Poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) (PZS) nanotubes were evaluated as an efficient adsorbent for the removal of Rhodamine B (RhB), a cationic dye from aqueous solution. The as-synthesized adsorbent (PZS nanotubes) were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR) and N2 adsorption/desorption isotherms. The factors influencing the adsorption efficiency and capacity had been systematically studied. Results showed that the adsorption was highly dependent on temperature, initial RhB concentration and adsorbent dose. Effects of initial solution pH indicate that the adsorption can proceed in both basic and acidic environment. The equilibrium absorption capacity at 25°C can reach up to 35.58 mg/g within 60 min implying the adsorption procedure was highly rapid. The kinetic data was better described by the pseudo-second-order model with the correlation coefficient (R2 = 0.9981), and the adsorption process...

Hollow poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) (PZS) microspheres with cross-linked chemical structure have been prepared under mild conditions by using polystyrene (PS) microspheres as sacrificial templates, hexachlorocyclotriphosphazene (HCCP) and 4,4′-sulfonyldiphenol (BPS) as comonomers, and triethylamine (TEA) as acid-acceptor. A template-induced assembly mechanism has been proposed to explain the formation of the hollow PZS microspheres. The as-prepared PS@PZS composites and hollow PZS microspheres were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectrometry, thermogravimetric analysis (TGA), and elemental analysis. The shell thickness of the hollow PZS microspheres can be controlled by adjusting the feed ratio of sacrificial templates to comonomers. An application study for the hollow PZS microspheres as a support of Au nanoparticles was carried out. The results show that Au nanoparticles with a size of about 5–8 nm were uniformly attached to the surface of the hollow PZS microspheres and the hollow PZS/Au hybrids displayed good catalytic properties with the reduction of 4-nitrophenol to 4-aminophenol as the model catalysis reaction.

Polydopamine (PDA) microspheres were synthesized by a facile oxidative polymerization method and used as a high-efficiency adsorbent for the removal of a cationic dye (methylene blue, MB) from aqueous solution. Characterizations of the as-synthesized PDA microspheres and PDA microspheres-MB (MB absorbed PDA microspheres) systems were performed using several techniques such as SEM, TEM, FTIR, N2 adsorption/desorption isotherms, particle size and zeta potential analysis. The effects of initial solution pH, temperature, initial concentration, and contact time were systematically investigated. Results showed the adsorption capacity at 25 °C could reach up to 90.7 mg/g. Besides, adsorption kinetics showed that the adsorption behavior followed the pseudo-second-order kinetic model. The equilibrium adsorption data fitted the Langmuir isotherm well. Thermodynamic analyses showed that the adsorption was endothermic and spontaneous, and it was also a physisorption process. In addition, the possible adsorption mechanism was also proposed based on the experimental results.

Study design This is a cross-sectional study. Objective To investigate the feasibility and safety of a novel iliosacral screw placement for sacrum-pelvis in adult pelvis by computed tomography (CT) reconstruction. Summary of background data The optimal technique of spino-pelvic fixation is still being developed and redefined. However, neither the relevant anatomic parameters nor the potential spinal canal involvement for a novel iliosacral screw placement have been clearly analyzed. Methods A total of 60 adults with normal pelvis, with the age ranging from 24 to 79 years old, were included in this study. Based on three-dimensional (3D) CT reconstruction of each pelvis, virtual iliosacral screw channel was identified bilaterally, the trajectory of which was characterized with the optimal width and length from the ilium to the sacrum. The virtual iliosacral screw channel that holding the greatest width and length of osseous channel was measured by rotating the 3D pelvis. Measurements of the determined channel on either side included iliosacral-screw-related and connector-related parameters. Results There was a virtual iliosacral screw channel passing through the ilium, the iliosacral joint and then into the sacrum on either side of each pelvis. The caudal angle, convergent angle, and maximal length were 16.3 ± 3.0°, 61.3 ± 5.9°, 97.0 ± 5.6 mm in male, respectively. In female, they were 16.4 ± 3.9°, 63.0 ± 5.5° and 96.2 ± 6.0 mm, respectively. The ideal direction of the connector was from posteromedial to anterolateral. The cephalad angle, divergent angle, and embedding depth of the connector were 28.0 ± 5.7°, 28.7 ± 5.9° and 19.0 ± 2.9 mm in male, respectively. In female, they were 26.7 ± 6.1°, 27.0 ± 5.5° and 16.4 ± 2.6 mm, respectively. Conclusion It is safe and feasible to place the iliosacral screw when performing this novel instrumentation. Preoperative CT imaging and 3D reconstructions may help to determine the correct entry point and the trajectory of iliosacral screw. Level of evidence 5.

Participatory sensing is the concept of recruiting mobile devices to collect data and engage computing. However, there are many problems in this mode of cooperation, poor quality of received information caused by task executors has been one of them. So incentive mechanism is proposed for attracting users to participate in and submit high-quality data. Inspired by contract theory, we model participatory sensing as a contractual relationship and design rewards for multiple results depending on the quality requirement of tasks which maximize the benefit of task publisher. Under complete information scenario where task executors' efforts can be observed and incomplete information scenario where task executors' efforts cannot be observed, we obtain optional contract for task executors respectively through solving maximization problem. Finally, we evaluate our contract based approach by thorough simulations to show its effectiveness and accuracy and analyze the influence of result, cost and probability on reward from aspects of theory and reality.

Compressive sensing (CS) provides an energy-efficient paradigm for data gathering in wireless sensor networks (WSNs). However, the existing work on spatial-temporal data gathering using compressive sensing only considers either multi-hop relaying based or multiple random walks based approaches. In this paper, we exploit the mobility pattern for spatial-temporal data collection and propose a novel mobile data gathering scheme by employing the Metropolis-Hastings algorithm with delayed acceptance, an improved random walk algorithm for a mobile collector to collect data from a sensing field. The proposed scheme exploits Kronecker compressive sensing (KCS) for spatial-temporal correlation of sensory data by allowing the mobile collector to gather temporal compressive measurements from a small subset of randomly selected nodes along a random routing path. More importantly, from the theoretical perspective we prove that the equivalent sensing matrix constructed from the proposed scheme for spatial-temporal compressible signal can satisfy the property of KCS models. The simulation results demonstrate that the proposed scheme can not only significantly reduce communication cost but also improve recovery accuracy for mobile data gathering compared to the other existing schemes. In particular, we also show that the proposed scheme is robust in unreliable wireless environment under various packet losses. All this indicates that the proposed scheme can be an efficient alternative for data gathering application in WSNs .

The accurate short-term traffic flow prediction can provide timely and accurate traffic condition information which can help one to make travel decision and mitigate the traffic jam. Deep learning (DL) provides a new paradigm for the analysis of big data generated by the urban daily traffic. In this paper, we propose a novel end-to-end deep learning architecture which consists of two modules. We combine convolution and LSTM to form a Conv-LSTM module which can extract the spatial-temporal information of the traffic flow information. Furthermore, a Bi-directional LSTM module is also adopted to analyze historical traffic flow data of the prediction point to get the traffic flow periodicity feature. The experimental results on the real dataset show that the proposed approach can achieve a better prediction accuracy compared with the existing approaches.

In order to provide the users with reliable wireless communication service in high-speed mobility scenarios, we need to obtain channel state information by channel estimation. However, the wireless channel presents a characteristic of dynamic change in high-speed mobility environments. It will bring great challenge to channel estimation. Aiming at the high-speed railway communication system, the issue of the fast time-varying channel estimation is investigated in this paper. The impulse response of the fast time-varying channel is modeled as the product of the basis functions and the coefficients by introducing a basis expansion model (BEM). Meanwhile, the comb pilot clusters are inserted in frequency domain. The coefficients of basis functions are derived by the least-square estimation criterion so as to realize the estimation of the channel impulse response. Simulation results show that optimization generalized complex exponential BEM (OGCE-BEM) has the smallest normalized mean square error among the various types of BEMs.

Harvesting energy from the environment is a method to improve the energy utilization efficiency. However, most renewable energy has a poor stability due to the weather and the climate. The reliability of the communication systems will be influenced to a large extent. In this paper, an energy-efficient downlink resource allocation problem is investigated in the energy harvesting communication systems by exploiting wireless power transfer technology. The resource allocation problem is formulated as a mixed-integer nonlinear programming problem. The objective is to maximize the energy efficiency while satisfying the energy causality and the data rate requirement of each user. In order to reduce the computational complexity, a suboptimal solution to the optimization problem is obtained by employing a quantum-behaved particle swarm optimization (QPSO) algorithm. Simulation results show that the QPSO algorithm has a higher energy efficiency than the traditional particle swarm optimization (PSO) algorithm.

High data quality and low sensing cost are two primary goals in large-scale mobile crowdsensing applications. The oversampling and the undersampling are common problems which always result in a high cost or low data quality that can not satisfy the system requirement. To address this problem, taking into account low-rank latent structure, we propose a compressive and adaptive data sampling scheme (CAS) which exploits adaptivity to identify locations which are highly informative for learning the low-dimensional space of the data matrix. In contrast to existing random sampling methods, it involves a three-pass sampling procedure that firstly assigns a fraction of samples to estimate general information, then samples those more informative locations for exact recovery and finally estimates the values of the unsensing locations. Evaluations on synthetic datasets and real datasets for air quality monitoring show the effectiveness of CAS. The experimental results demonstrate that the proposed scheme is able to not only significantly improve the sensing data quality but also reduce the computation complexity comparing with the state-of-the-art matrix completion methods.

The recent advances of compressive sensing (CS) have witnessed a great potential of traffic condition estimation in road networks. In this paper, we propose a traffic estimation approach that applies compressive sensing technique to achieve a city-scale traffic estimation with only a small number of vehicle probes. In particular, we construct a new type of random matrix for CS which can significantly reduce the number of vehicle probes for traffic estimation. Furthermore, we also propose a novel representation matrix to better exploit the correlations of road network to improve the accuracy of traffic estimation. We analyze the incoherence between random measurement matrix and sparsity representation basis. Finally, we validate the effectiveness of the proposed approach through extensive simulations by real-world dataset.

STUDY DESIGN A retrospective study. OBJECTIVE To determine the incidence and risk factors of coronal decompensation after posterior-only thoracolumbar hemivertebra (HV) resection and short fusion in patients younger than 5-years old. SUMMARY OF BACKGROUND DATA Postoperative coronal decompensation may occur in operated patients during the follow up. However, there is a paucity of valid data regarding this complication in very young patients with thoracolumbar HV. METHODS This study reviewed a consecutive series of patients (younger than 5 years) who had undergone posterior-only hemivertebrectomy and short fusion from January 2006 to December 2014. They had a minimum follow-up of 24 months. According to the coronal compensation behavior, they were divided into two groups: Group P (progressed, curve decompensated beyond twenty degrees) and Group NP (nonprogressed, curve well compensated). RESULTS There were 179 patients included in this study. Mean age at surgery was 38 ± 11 months. Mean follow-up was 41 ± 11 months. Postoperative coronal decompensation was identified in 18 patients (rate, 10.1%) who constituted Group P. The remaining 161 patients had a well-compensated pattern. In contrast to Group NP, the patients in Group P had greater preoperative lowest instrumented vertebra (LIV) translation (18.5 mm ± 6.4 mm vs. 10.5 mm ± 4.9 mm, P

Participatory sensing is a rising paradigm which utilizes mobile phones to collect data and build application on the cloud. But there are many problems to be resolved, poor quality of received information caused by task executors has been one of them. So incentive mechanism is essential for attracting users to participate in and submit high-quality data. Inspired by contract theory, we model participatory sensing as a contractual relationship and devote to design reasonable rewards for relevant results to maximize the benefit of task publisher. Under complete information scenario where task executors' efforts can be observed and incomplete information scenario where task executors' efforts can not be observed, we take advantage of maximization problem to infer the optional contract reward for task executors. In addition, based on the utility of task publisher, we propose optimal effort and optimal effort discriminant inequality (OEDI). Furthermore, we discuss the influence of noise, cost and boundary on optimal effort from aspects of theory and reality. Finally, we evaluate our contract-based approach by thorough simulations to show its effectiveness and accuracy.

Accurate prediction of the traffic state can help to solve the problem of urban traffic congestion, providing guiding advices for people's travel and traffic regulation. In this paper, we propose a novel short-term traffic flow prediction algorithm, which is based on Multi-kernel Support Vector Machine (MSVM) and Adaptive Particle Swarm Optimization (APSO). Firstly, we explore both the nonlinear and randomness characteristic of traffic flow, and hybridize Gaussian kernel and polynomial kernel to constitute the MSVM. Secondly, we optimize the parameters of MSVM with a novel APSO algorithm by considering both the historical and real-time traffic data. We evaluate our algorithm by doing thorough experiment on a large real dataset. The results show that our algorithm can do a timely and adaptive prediction even in the rush hour when the traffic conditions change rapidly. At the same time, the prediction results are more accurate compared to four baseline methods.

A retrospective study.To determine the incidence and risk factors of proximal junctional kyphosis (PJK) in young children who underwent posterior instrumented spinal fusion.PJK is a well-recognized postoperative complication in adults and adolescents. However, there is a paucity of valid data with regard to PJK in young children with congenital scoliosis (CS) who were treated with posterior correction surgery.This study reviewed the charts and radiographs of a consecutive series of young children with CS who underwent posterior instrumentation and fusion (≥4 levels) from January 2008 to May 2013. The patients were followed up for more than 24 months. Radiographic measurements were made preoperatively and throughout the follow-up period. From sagittal images, the following values were obtained: proximal junctional angle, sagittal vertical axis, pelvic incidence, thoracic kyphosis, lumbar lordosis, and segmental kyphosis.Totally 113 children were recruited in this study. The average age at surgery was 6.6 years, and the average follow-up period was 48.8 months. PJK occurred in 21 of the 113 patients and were mostly classified as ligamentous failure. In comparison with the non-PJK group, the PJK group showed greater preoperative Thoracic kyphosis (TK) (45.9° vs. 37.3°, P = 0.027), longer fusion levels (6.6 vs. 5.4, P 0.01), and greater segmental kyphosis (SK) change (30.1° vs. 11.2°, P = 0.002). Both a change in SK greater than 30° and a preoperative TK greater than 40° were independent risk factors associated with PJK. In the PJK group, the average PJA increased by 12.4° at 3 months postoperatively and followed by slight improvement till the final follow-up.This study demonstrates a high rate of PJK in young children after correction surgery for CS. PJK mainly occurs within 3 months postoperatively and its risk factors include preoperative hyperkyphosis, over-correction of kyphosis, and ligamentous failure.4.

High-speed train communication system is a typical high-mobility wireless communication network. Resource allocation problem has a great impact on the system performance. However, conventional resource allocation approaches in cellular network cannot be directly applied to this kind of special communication environment. A multi-domain resource allocation strategy was proposed in the orthogonal frequency-division multiple access (OFDMA) of high-speed. By analyzing the effect of Doppler shift, sub-channels, antennas, time slots and power were jointly considered to maximize the energy efficiency under the constraint of total transmission power. For the purpose of reducing the computational complexity, noisy chaotic neural network algorithm was used to solve the above optimization problem. Simulation results showed that the proposed resource allocation method had a better performance than the traditional strategy.

A novel portable biosensor for sensitive and selective detection of platelet-derived growth factor-BB (PDGF-BB) had been developed based on the specific recognition between aptamer and protein using a personal glucose meter (PGM) as readout. In the presence of PDGF-BB, the primary aptamer of PDGF-BB which is bound to the surface of streptavidin magnespheres paramagnetic particles (SA-PMPs) reacts quantitatively with invertase-functionalized secondary aptamer of PDGF-BB to form a stable complex, resulting in the attachment of invertase on the SA-PMPs. Subsequently, the invertase catalyzes the hydrolysis of sucrose to produce a large amount of glucose and quantitative readout by the PGM. The enhanced signal of the PGM has a relationship with the concentration of PDGF-BB in the range of 1.0 × 10(-14) M~3.16 × 10(-12) M, and the detection limit is 2.9 fM. The proposed portable biosensor had been successfully applied to assay the PDGF-BB in saliva samples.

Poly(cyclotriphosphazene-co-4,4′-sulfonyldiphenol) (PZS) nanospheres were prepared by a simple precipitation polymerization method and used as an efficient and specific adsorbent for the removal of methylene blue (MB), a cationic dye from aqueous solution. The as-synthesized PZS nanospheres were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The effects of initial solution pH, initial MB concentration, adsorbent dosage, and contact time on MB adsorption have been investigated. Results showed that the neutral and basic solutions benefited MB adsorption. The pseudo-second-order model could be better fit to the experimental data compared with the pseudo-first-order kinetic adsorption model. In addition, Weber's intraparticle diffusion model was used to further understand the adsorption process. The mechanism of efficient and specific adsorption possibly involved the presence of numerous electron-rich N, P and S atoms in PZS, the electrostatic attraction and π-π stacking interactions between PZS nanospheres and MB.

In this paper, we have examined the crack formation of weathered granite by monitoring acoustic emissions (AE) under uniaxial compression. Except for the uniaxial compressive strength (UCS), the thresholds have been determined for crack closure, crack initiation and crack damage, respectively. Moreover, the relationship has been preliminarily established between the AE energy and the rock damage variable. Compared to the deformation and failure characteristics of unweathered granite, the uniaxial compression strength and the elastic modulus of weathered granite are significantly decreased. Additionally, the acoustic emissions are consistently observed in the stage of original crack closure and loading-induced crack initiation followed by crack formation. The crack volumetric strain is an indicator for the crack closure and crack initiation, while the bulk volume strain is an indicator to the crack damage threshold. In elastic phase, AE signals are mainly caused by the micro-damage, while in plastic phase, AE signals are attributed to the plastic deformation. The AE cumulative parameter curves describe the damage evolution process, including the damage initiation and damage development for the weathered granite. The b-value of AE accompanying rock-fracturing is estimated, and oscillates between 1.0 and 1.7 on a long-term decreasing background, indicating a close correlation with the alternate occurrence of clustering. Of particular interest is that the two PZTs are appropriate for monitoring acoustic emissions under uniaxial compression.

BACKGROUND Growing rods (GRs) pose a higher risk of kyphosis gain while improving coronal deformity with intermittent distractions in early-onset scoliosis (EOS), but in turn, increased kyphosis may also affect GR correction outcomes. However, there is a paucity of data regarding the effect of GRs on the sagittal spinal profiles in hyperkyphotic EOS. Thus, we aim to demonstrate how hyperkyphotic EOS responds to GRs treatment. METHODS Forty patients treated with GRs for EOS were included and categorized into a normal kyphosis (N) group [20 degrees≤thoracic kyphosis (TK)≤50 degrees] or hyperkyphosis group (K) group (TK≥50 degrees). Radiographic measurements were performed before and after the index surgery and at the last follow-up. The complications were identified and classified using the surgical complications grading system. RESULTS The N group included 13 patients with dual GRs and 6 patients with a single GR. The K group consisted of 17 patients with dual GRs and 4 patients with a single GR. The mean age at surgery in the N and K groups was 6.2±1.8 and 6.4±2.1 years, respectively. The N and K groups, respectively, had an average number of lengthenings of 4.2±2.0 and 4.3±2.3, with an average follow-up of 4.7±1.9 and 4.6±2.1 years, respectively. In the K group, TK was markedly reduced after the index surgery and slightly increased during follow-up, whereas changes in TK in the N group were not significant. The complication rate in the K group was significantly higher than in the N group (81.0% vs. 47.4%, P=0.046). The most common implant-related and alignment-related complication in both groups was rod fracture (17.5%) and proximal junctional kyphosis (22.5%), respectively. The complication events in the N group were 5 with grade I and 5 with grade IIA, whereas in the K group there were 8 with grade I and 11 with grade IIA. CONCLUSIONS GRs can effectively correct hyperkyphotic EOS, with the sagittal profile being successfully restored to normal range. However, hyperkyphotic EOS tends to experience more complications such as rod fracture and PJK. LEVEL OF EVIDENCE Level III.

In order to make full use of the massive vehicle networking data and dig out the characteristics of the vehicle driving behaviors, the analysis of the massive vehicle networking data is indispensable. And clustering analysis is an effective way to extract the information which can guide and supervise the vehicles. In this paper, we propose a novel initial clustering center selection algorithm based on the image recognition. In addition, in order to shorter the time of the clustering algorithm, we improve the e-Link based on the massive vehicle networking data. We refer to image-based clustering algorithm applied on matching map of the vehicle networking data and ultimately obtain the traffic hot spot map of the urban roads by the clustering analysis. We evaluate our algorithm by doing thorough simulation on the massive data of vehicles in Fuzhou city. The result shows that when compared to the traditional clustering algorithms with great randomness in selection, the image-based clustering algorithm consumes less time in the case of massive vehicle networking data. And through the analysis of the trajectory data, the traffic hot spot map can be formed and practically reflects the practical traffic flow of Fuzhou city.

SUMMARY Power line communication is attracting increasing attention for its characteristics of easy availability and low cost. Frequency shift keying with the virtue of antijamming capability is suitable for the low signal-to-noise ratio power line environment. The principle of the frequency shift keying communication system based on momentary Fourier transform (MFT) algorithm is provided first in this paper. Theoretically, the twiddle factor in the MFT algorithm is a decimal with infinite length. However, when it is applied on digital signal processor (DSP), the registers with finite length in DSP lead to the inaccuracy of the twiddle factor. Thus, the MFT algorithm with recursive form will cause accumulative error as a result. We analyze the impact of the inaccurate twiddle factor on the MFT algorithm from a novel point of view, by which the MFT algorithm is considered as a linear time invariant system. We prove that the accumulative error would not disperse when the modulus of the twiddle factor is smaller than 1. Simulation results show that the truncation approach is more effective than both carrying and rounding methods in a practical system. In addition, the number of significant digits of truncated twiddle factor must be chosen larger than 4 to overcome the problem of accumulative error.Copyright © 2012 John Wiley & Sons, Ltd.

Phototunable biomaterial-based resistive memory devices and understanding of their underlying switching mechanisms may pave a way toward new paradigm of smart and green electronics. Here, resistive switching behavior of photonic biomemory based on a novel structure of metal anode/carbon dots (CDs)-silk protein/indium tin oxide is systematically investigated, with Al, Au, and Ag anodes as case studies. The charge trapping/detrapping and metal filaments formation/rupture are observed by in situ Kelvin probe force microscopy investigations and scanning electron microscopy and energy-dispersive spectroscopy microanalysis, which demonstrates that the resistive switching behavior of Al, Au anode-based device are related to the space-charge-limited-conduction, while electrochemical metallization is the main mechanism for resistive transitions of Ag anode-based devices. Incorporation of CDs with light-adjustable charge trapping capacity is found to be responsible for phototunable resistive switching properties of CDs-based resistive random access memory by performing the ultraviolet light illumination studies on as-fabricated devices. The synergistic effect of photovoltaics and photogating can effectively enhance the internal electrical field to reduce the switching voltage. This demonstration provides a practical route for next-generation biocompatible electronics.

Increasing evidence has indicated that glycans and their interactions with glycan-specific binding proteins have crucial roles in most physiological processes. One emerging topic in biomaterials is the construction of smart materials capable of recognizing and responding to these valuable glycans. However, because of the complicated compositions and structures as well as the low abundances and microheterogeneity of glycans, developing glycan-responsive materials with a high sensitivity and specificity is a long-term, challenging goal. Here, we report a biomimetic polymer capable of capturing and discriminating sialo-complex-type glycans with the core Neu5Ac-Gal-GlcNAc-Man sequence, which is one of the most effective biomarkers for cancer detection. As an optimized dipeptide, L-Asp-L-Phe has a strong but differential binding affinity for N-acetyl-neuraminic acid (Neu5Ac), N-acetyl-glucosamine (GlcNAc), galactose (Gal), and mannose (Man), which are the core construction units of sialylated glycans. In addition, the L-Asp-L-Phe-grafted polyethyleneimine film displays remarkable adsorption behavior for the model sialylated glycans and can discriminate their linkage isomers, which is accompanied by significant changes in the surface morphology and stiffness. These features facilitate the highly selective capture of sialylated glycopeptides from complex protein samples using PEI-g-L-Asp-L-Phe-modified mSiO2@SiO2@Fe3O4 core-shell microspheres. The mechanism analysis demonstrates that the favorable polymeric spatial structures and multiple synergetic hydrogen-bonding interactions among the dipeptides and glycan are the main driving forces, indicating a clear direction for designing glycan-specific biomaterials. A polymer that recognizes structural variations between different glycans could improve detection of breast and prostate cancer. Glycans attach to many kinds of biological molecules, making them essential information carriers between cells during processes such as tumor metastasis. Taolei Sun from Wuhan University of Technology and co-workers have now grafted olgiopeptide receptors onto polyethylenimine anchors for materials that capture potential glycan biomarkers from complex sample mixtures. Most glycan sensors only spot differences between the terminal saccharide groups that become attached to polymer surfaces. In contrast, the Chinese team's approach draws on hydrogen-bonding patterns found in nature to identify glycans with specific three-dimensional compositions and biomolecular connections. Immobilization of the smart polymer onto core-shell beads made from iron oxide and silicia allowed selected glycans to be easily separation by using magnetic fields. Sialylated complex-type N-linked glycans on cytomembrane are acknowledged as effective biomarkers for cancer diagnose. Owing to their complicated structures and low-abundance, developing glycan-targeted materials with high specificity is quite challenging. To resolve this problem, we reported a biomimetic design for dipeptide-based smart polymer, as well as its excellent performance in sialo-N-linked glycan recognition, adsorption, linkage isomers discrimination and high-efficiency capture from complex protein sample.

Adolescent idiopathic scoliosis (AIS) is a structural deformity of the spine affecting millions of children. As a complex disease, the genetic aetiology of AIS remains obscure. Here we report the results of a four-stage genome-wide association study (GWAS) conducted in a sample of 4,317 AIS patients and 6,016 controls. Overall, we identify three new susceptibility loci at 1p36.32 near AJAP1 (rs241215, Pcombined=2.95 × 10−9), 2q36.1 between PAX3 and EPHA4 (rs13398147, Pcombined=7.59 × 10−13) and 18q21.33 near BCL-2 (rs4940576, Pcombined=2.22 × 10−12). In addition, we refine a previously reported region associated with AIS at 10q24.32 (rs678741, Pcombined=9.68 × 10−37), which suggests LBX1AS1, encoding an antisense transcript of LBX1, might be a functional variant of AIS. This is the first GWAS investigating genetic variants associated with AIS in Chinese population, and the findings provide new insight into the multiple aetiological mechanisms of AIS., The authors perform a genome-wide association study of adolescent idiopathic scoliosis patients of Han Chinese descent, and identify 3 new loci for disease susceptibility.

Vehicular networks have become as an important platform to monitor metropolitan-scale traffic information. However, it is a challenge to deliver and process the huge amount of data from vehicular devices to a data center. By studying a large number of taxi data collected from around 3,000 taxis from Shenzhen city in China, we find that the data readings collected by vehicular devices have a strong spatial correlation. In this paper, we propose a novel scheme based on compressive sensing for traffic monitoring in vehicular networks. In this scheme, we construct a new type of random matrix with only one nonzero element of each row, which can significantly reduce the number of data needed to be transmitted while guaranteeing good reconstruction quality at the data center. Simulation results demonstrate that our scheme can achieve high reconstruction accuracy at a much lower sampling rate.

We report InAs quantum dot infrared photodetectors that utilize In0.15Ga0.85As strain-relief cap layers. These devices exhibited normal-incidence photoresponse peaks at 8.3 or 8.8 μm for negative or positive bias, respectively. At 77 K and −0.2 V bias the responsivity was 22 mA/W and the peak detectivity D* was 3.2×109 cm Hz1/2/W.

An InAs/AlGaAs quantum-dot infrared photodetector based on bound-to-bound intraband transitions in undoped InAs quantum dots is reported. AlGaAs blocking layers were employed to achieve low dark current. The photoresponse peaked at 6.2 /spl mu/m. At 77 K and -0.7 V bias, the responsivity was 14 mA/W and the detectivity, D*, was 10/sup 10/ cm/spl middot/Hz/sup 1/2//W.

Using high-resolution low-energy electron diffraction, we find a "correlation" of the c(2 × 2) reconstruction of the ZnSe(001) surface across [010]- and [100]-oriented steps. The difference of the corresponding step vectors is incompatible with the c(2 × 2) reconstruction. Thus intersection points of [010]- and [100]-oriented steps at 2D island corners or kinks induce c(2 × 2) anti-phase boundaries along the [10] direction. This mechanism yields a non-local contribution to the step energy which generally could be important for the explanation of step morphologies, e.g., of the recently observed, self-organized checkerboard-like arrangement of nano-terraces on a vicinal CdTe(001) surface.

The preservation of spinal growth and prevention of pulmonary compromise in early onset scoliosis (EOS) pose particularly challenging problems for clinician and patients. Maintaining spinal and thoracic growth is critical for expansion of the thoracic cavity and the prevention of thoracic insufficiency syndrome. Nowadays, growing rod technique has been proven to be the optimal surgical treatment for this population, regardless of distraction-based or auto-growing instrumentation constructs.

A fluorometric method for pyrophosphatase (PPase) activity detection was developed based on click chemistry. Cu(II) can coordinate with pyrophosphate (PPi), the addition of pyrophosphatase (PPase) into the above system can destroy the coordinate compound because PPase catalyzes the hydrolysis of PPi into inorganic phosphate and produces free Cu(II), and free Cu(II) can be reduced by sodium ascorbate (SA) to form Cu(I), which in turn initiates the ligating reaction between nonfluorescent 3-azidocoumarins and terminal alkynes to produce a highly fluorescent triazole complex, based on which, a simple and sensitive turn on fluorometric method for PPase can be developed. The fluorescence intensity of the system has a linear relationship with the logarithm of the PPase concentration in the range of 0.5 and 10 mU with a detection limit down to 0.2 mU (S/N = 3). This method is cost-effective and convenient without any labels or complicated operations. The proposed system was applied to screen the potential PPase inhibitor with high efficiency. The proposed method can be applied to diagnosis of PPase-related diseases.

Use of pedicle screws has been popularized in the treatment of pediatric spinal deformity. Despite many studies regarding the effect of pedicle screws on the immature spine, there is no study concerning the impact of addition of crosslink to pedicle-screw-based instrumentation on the development of the spinal canal in young children. This study aims to determine the influence of the screw–rod-crosslink complex on the development of the spinal canal. This study reviewed 34 patients with congenital scoliosis (14 boys and 20 girls) who were treated with posterior-only hemivertebrectomy and pedicle-screw-based short-segment instrumentation before the age of 5 years. The mean age at surgery in this cohort was 37 ± 11 months (range 21–57 months). They were followed up for at least 24 months. Of these patients, 10 underwent only pedicle screw instrumentation without crosslink, and 24 with additional crosslink placement. The vertebrae were divided into three regions as follows: (1) S-CL (screw-crosslink) region, in which the vertebrae were inserted with bilateral pedicle screws and two rods connected with the crosslink; (2) S (screw) region, in which the vertebrae were inserted with bilateral pedicle screws but without crosslink; (3) NS (no screws) region, which comprised vertebrae cephalad or caudal to the instrumented region. The area, anteroposterior and transverse diameters of the spinal canal were measured at all vertebrae on the postoperative and last follow-up computed tomography axial images. The instrumentation-related parameters were also measured, including the distance between the bilateral screws and the screw base angles. The changes in the above measurements were compared between each region to evaluate the instrumentation’s effect on the spinal canal growth. The mean follow-up was 37 ± 13 months (range 24–68 months) and the mean age at the last follow-up was 74 ± 20 months (range 46–119 months). In each region, the spinal canal dimensions significantly increased during the follow-up period. There was no significant difference in the spinal canal growth rate between the S and NS regions or between the S-CL and NS regions. Besides, a comparison of the S-CL and S regions regarding the changes in the measurements of the instrumentation construct revealed no significant differences. Pedicle-screw-based instrumentation does not cause retardation of the development of the spinal canal in young children. Moreover, use of the crosslink added to the screw–rod instrumentation also demonstrates no negative effect on the growth of the spinal canal. Thus, the addition of the crosslink to short screw-based instrumentation is recommended as an alternative to increase fixation stability in growing patients, even in very young pediatric population.

We report on a study of n-type quantum dot (QD) infrared photodetectors (QDIPs) based on InAs/GaAs QDs grown via an innovative technique called punctuated island growth. The electronic structure of the QDs inserted in QDIP devices is comprehensively investigated with photoluminescence, and intra- and interband photocurrent spectroscopy. The influence of AlGaAs layers inserted in active regions on the performance of the QDIPs is examined. Bias and temperature dependence of intraband photoresponse of QDIPs with undoped active region is examined. Initial results on intraband photoresponsivity and detectivity of these QDIPs at 77 K are reported.

We have performed a comprehensive investigation of n-type quantum dot infrared photodetectors (QDIPs) based on InAs/GaAs epitaxical island quantum dots (QDs) grown via the innovative punctuated island growth technique. The structural properties of the QDs were investigated with cross-sectional transmission electron microscopy and atomic force microscopy. The electronic properties of the QDs inserted in QDIP devices were investigated with photoluminescence (PL), PL excitation, and intra- and inter-band photocurrent spectroscopy. The influence of AlGaAs layers inserted into the QDIP active regions on the performance of dark current and inter- and intra-band photocurrent was examined. Initial results on intra-band responsivity and detectivity of these QDIPs at 77 K with undoped active region show promise for application.