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BACKGROUND Fracture risk assessment in children with benign bone lesions of long bones remains poorly investigated. AIM To investigate the risk factors for pathological fracture in children with benign bone lesions and to propose a modified scoring system for quantitative analysis of the pathologic fracture risk. METHODS We retrospectively reviewed 96 pediatric patients with benign bone lesions. We compared radiographic and clinical features between 40 patients who had fractures through a benign bone lesion and 56 who had no fracture. Information including histological diagnosis, anatomical site, radiographic appearance, severity of pain, and lesion size was recorded for the patients. A modified scoring system was proposed to predict the risk of fracture. RESULTS The univariate comparisons showed a significant difference between the fracture and non-fracture groups in terms of lesion type, pain, lesion-to-bone width, and axial cortical involvement of the patients (P < 0.05). Lesion type, pain, lesion-to-bone width, and axial cortical involvement were independently correlated with an increased risk of fracture. The mean score of the fracture group was 7.89, whereas the mean score of the non-fracture group was 6.01. The optimum cut-off value of the score to predict pathological fracture was 7. The scoring system had a sensitivity of 70% and a specificity of 80% for detecting patients with fractures. The Youden index was 0.5, which was the maximum value. The area under the receiver operator characteristic was 0.814. CONCLUSION Lesion type, pain, lesion-to-bone width, and axial cortical involvement are risk factors for pathological fracture. The modified scoring system can provide evidence for clinical decision-making in children with benign bone lesions. A bone lesion with a total score > 7 indicates a high risk of a pathologic fracture and is an indication for prophylactic internal fixation.

The spatial pattern of plant population is one of primary issues in ecological research. Point pattern analy-sis is considered as an important method to study the spatial pattern of plant population. Ripley's植物种群空间格局是生态学研究的基本问题之一, 点格局分析已成为植物种群空间格局研究的重要方法之一, 其中, Ripley's

Conductor corona performance is significant in the evaluation of electromagnetic environment for high voltage power transmission lines. The influence of artificial contaminated conductors on corona discharge was studied and turned out to be complicated. The ionized field strength on the corona cage was measured by field mill. Meanwhile, photos of corona plumes were photographed and grayed to quantitate the corona discharge intensity. Subsequently, a calculation model for equivalent electric field strength coefficient was established to evaluate the discharge intensity of conductors in coaxial cylindrical electrode. It could be found the computational results achieved an agreement with the observed experimental phenomena. By means of simulation results, a reasonable explanation was given to the finding that the closer the distance between the two protrusions was, the lower the corona discharge intensity and higher corona inception voltage of the conductors would be. In summary, the distributions of corona sources played an important role in the corona discharge and this work would provide an important reference for the evaluation of corona effects on the surface of contaminated conductors.

In view of the problems that the encoding complexity of quasi-cyclic low-density parity-check (QC-LDPC) codes is high and the minimum distance is not large enough which leads to the degradation of the error-correction performance, the new irregular type-II QC-LDPC codes based on perfect cyclic difference sets (CDSs) are constructed. The parity check matrices of these type-II QC-LDPC codes consist of the zero matrices with weight of 0, the circulant permutation matrices (CPMs) with weight of 1 and the circulant matrices with weight of 2 (W2CMs). The introduction of W2CMs in parity check matrices makes it possible to achieve the larger minimum distance which can improve the error- correction performance of the codes. The Tanner graphs of these codes have no girth-4, thus they have the excellent decoding convergence characteristics. In addition, because the parity check matrices have the quasi-dual diagonal structure, the fast encoding algorithm can reduce the encoding complexity effectively. Simulation results show that the new type-II QC-LDPC codes can achieve a more excellent error-correction performance and have no error floor phenomenon over the additive white Gaussian noise (AWGN) channel with sum-product algorithm (SPA) iterative decoding.

A new copper-catalyzed oxidative difunctionalization of enol ethers with α-amino carbonyl compounds and hydroperoxides is developed. This method is experimentally simple while allowing for regioselective access to 2-amino-3,4-dioxy carbonyl compounds in good yields, and represents the first example of alkene oxyalkylation through C(sp(3))-H functionalization.

2,3-Epoxy ketones [(III) and (V)] are synthesized through an oxidative radical pathway with a broad substrate scope and excellent selectivity control.

Stainless steel (SS)/carbon steel (CS) clad plates were generated by means of the all-around weld of interface and vacuuming (AAWIV) followed by hot rolling, wherein AAWIV was utilized for controlling the interface oxidation during hot rolling. The structure near the interface was analyzed by optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The mechanical properties of SS/CS clad plates were investigated by tensile and shear as well as bend tests. The SS/CS interface is relatively flat and no visible separation appears. Line scanning analysis shows that diffusion of Cr and Ni from SS to CS and C from CS to SS occurred during bonding. Higher dislocation densities are observed in both layers of parent plates adhering to the interface. The SS/CS clad plates reveal higher yield, tensile and shear strengths. Both macroscopic delamination at the interface and fracture of base CS as well as intergranular fracture appearance of flyer plate are observed in the tensile test. The shear specimen fails in a ductile manner and the bend specimen tested shows no visible crack at the interface. Taking both interfacial structure and mechanical properties into account, the SS/CS clad plates exhibit sound bonding by the process of AAWIV and hot rolling.

Epidural analgesia is generally accepted as the most effective form of pain relief during labor. Remifentanil patient-controlled IV analgesia (PCIA), which is less invasive than epidural analgesia, may be an attractive alternative. In this meta-analysis, we compared the efficacy and safety of the 2 analgesic techniques for labor pain.Databases of PubMed, EMBASE, and Cochrane Library were searched independently by 2 reviewers to retrieve eligible randomized controlled clinical trials. The primary end points were pain scores at 1 and 2 hours, and the secondary end points were nausea, vomiting, pruritus, and umbilical artery pH values. Mean difference (MD) or risk ratio with 95% confidence intervals (CIs) were calculated for each end point. GRADE profiler was applied to assess the quality of evidence.Five eligible trials were retrieved and analyzed. We found that parturients with remifentanil PCIA had higher visual analog scale (10-cm scale) pain scores than those who received epidural analgesia at 1 hour (MD = 1.9 cm; 95% CI, 0.5-3.3; I = 94%) and 2 hours (MD = 3.0 cm; 95% CI, 0.7-5.2; I = 89%) after initiation of analgesia. There was no statistical difference between epidural analgesia and remifentanil PCIA in the incidence of nausea, vomiting, pruritus, or umbilical artery pH values. However, the CIs are quite wide and contain clinically significant differences. According to GRADE profiler, most end points had moderate quality except that pain scores at 1 hour were of low quality.This meta-analysis suggests that remifentanil PCIA is not superior to epidural analgesia in analgesic efficacy during labor. Given the wide CIs of the pooled results for secondary maternal and neonatal outcomes, definite conclusions cannot be drawn for those outcomes. Further studies are still warranted to validate these conclusions.

A practical and straightforward access to pyrazolo[3,4-c]quinolines by molecular sieve mediated dehydrogenative [2 + 2 + 1] heteroannulation of N-(o-alkenylaryl)imines with aryldiazonium salts is described using a sp3-hybrid carbon atom as a one-carbon unit. The reaction enables the formation of three new chemical bonds, a C–C bond and two C–N bonds, in a single reaction and features simple operation and excellent functional group tolerance.

In order to study the effect of humidity on the variations of positive DC corona discharge, an artificial climate chamber was developed to perform corona experiments. Based on the testing system, the photon counting rate, the total electric field strength and the ion current density on the ground level were measured by the UV imaging detector, the rotating DC electric field mill and the Wilson plate respectively. The relatively humidity during the experiments was kept within the range 40% to 90%. Moreover, the relationship between the calibration coefficient of the field mill and relatively humidity was also investigated. Experimental results showed that the photon counting rate and the total electric field increased with the raise of relative humidity, while the ion current density and the calibration coefficient decreased with the raise of relative humidity.

A practical and straightforward access to pyrazolo[3,4-c]quinolines by molecular sieve mediated dehydrogenative [2 + 2 + 1] heteroannulation of N-(o-alkenylaryl)imines with aryldiazonium salts is described using a sp(3)-hybrid carbon atom as a one-carbon unit. The reaction enables the formation of three new chemical bonds, a C-C bond and two C-N bonds, in a single reaction and features simple operation and excellent functional group tolerance.

High powered pulsed xenon lamp is widely used in laser inertial confinement fusion research as the optical pump source. And the cathode is very important for the performance of xenon lamp when operated as pump sources of lasers. With the development of material and technology new tungsten electrode doped with rare earth elements has been developed as cathode of xenon lamp.

A novel metal-free oxidative 1,2-alkylarylation of unactivated alkenes with the α-C(sp(3))-H bonds of acetonitriles for the synthesis of 5-oxo-pentanenitriles is presented. In the presence of TBPB (tert-butyl peroxybenzoate), a variety of α-aryl allylic alcohols underwent the 1,2-alkylarylation reaction with acetonitriles, giving 5-oxo-pentanenitriles in good to excellent yields. This method proceeds via the C(sp(3))-H oxidative coupling with the C-C double bond and 1,2-aryl-migration, and represents a new access to acyclic molecules through metal-free oxidative alkene 1,2-alkylarylation.

Polystyrene spheres were prepared by soap free emulsion polymerization method. The effects of styrene concentration, polymerization time and self-assemble methods on the diameter of the polystyrene spheres were investigated. Different size of polystyrene microspheres could be obtained by changing styrene concentration and polymerization time. Polystyrene templates with good uniform and highly ordered can be assembled by means of vertical deposition method. Based on this template, three-dimensional ordered macroporous (3DOM) perovskite-type oxides LaFeO3 were successfully prepared which were confirmed by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was also found that 1mol/L metal precursor solution which used ethanol solution of metal nitrates with citric acid addition gave the best 3DOM perovskite-type LaFeO3 oxides. The pores are uniform, flexible and arranged in a highly ordered form.

A calix[4]arene lipoic acid (C4LA) was synthesized by click chemistry in 62% yield. It was immobilized on Au surfaces via self-assembly to offer C4LA Self-Assembled Monolayers (SAMs). The SAMs show wettability and electrochemical impedance dual-signal response for methomyl with highly sensitivity and selectivity.

A study on the effect of fine particulate matter on the surface morphologies of conductors subjected to high positive dc voltages has been undertaken. A global distribution pattern of particulate matter was observed in the shape of parallel chains consisting of particle agglomerations. Based on a coupling model of electric and force fields, the dynamic progress of particles near conductor surfaces was investigated and the effects of forces exerted on the particles were analyzed. The experimental observations agreed well with calculated results. It was found that the interactions between particles played a critical role in the formation of agglomerations and parallel chains. The surface roughness and the corona discharge intensity of the conductors increased significantly as a result of the variation of surface morphologies.A study on the effect of fine particulate matter on the surface morphologies of conductors subjected to high positive dc voltages has been undertaken. A global distribution pattern of particulate matter was observed in the shape of parallel chains consisting of particle agglomerations. Based on a coupling model of electric and force fields, the dynamic progress of particles near conductor surfaces was investigated and the effects of forces exerted on the particles were analyzed. The experimental observations agreed well with calculated results. It was found that the interactions between particles played a critical role in the formation of agglomerations and parallel chains. The surface roughness and the corona discharge intensity of the conductors increased significantly as a result of the variation of surface morphologies.

A series of calix[10]crowns were synthesized for the first time. By reacting p-tert-butylcalix[10]arene with ethylene glycol ditosylate or polyethylene glycol ditosylates in a system of K2CO3/toluene or Cs2CO3/acetone, a series of calix[10]crowns such as 1,2-calix[10]crown-4, 1,3-calix[10]crown-2, 1,2-calix[10]crown-3, 1,3-calix[10]crown-3, 1,4-calix[10]crown-4 and 1,6-calix[10]crown-4 were obtained.

Water-soluble CdSe/ZnS quantum dots (QDs) were prepared via a simple sonochemical procedure using β-cyclodextrin (CD) as surface coating agent. The QDs displayed a sensitive emission enhancement for anthracene over other related polycyclic aromatic hydrocarbons, and the detection limit was around 1.6 × 10 −8 mol/L.

A new copper-catalyzed oxidative difunctionalization of enol ethers with α-amino carbonyl compounds and hydroperoxides is developed. This method is experimentally simple while allowing for regioselective access to 2-amino-3,4-dioxy carbonyl compounds in good yields, and represents the first example of alkene oxyalkylation through C(sp(3))-H functionalization.

A novel metal-free oxidative 1,2-alkylarylation of unactivated alkenes with the α-C(sp3)–H bonds of acetonitriles for the synthesis of 5-oxo-pentanenitriles is presented. In the presence of TBPB (tert-butyl peroxybenzoate), a variety of α-aryl allylic alcohols underwent the 1,2-alkylarylation reaction with acetonitriles, giving 5-oxo-pentanenitriles in good to excellent yields. This method proceeds via the C(sp3)–H oxidative coupling with the C–C double bond and 1,2-aryl-migration, and represents a new access to acyclic molecules through metal-free oxidative alkene 1,2-alkylarylation.

2,3-Epoxy ketones [(III) and (V)] are synthesized through an oxidative radical pathway with a broad substrate scope and excellent selectivity control.

Mono- and difunctionalization of a broad scope of non-activated alkenes is achieved with excellent chemoselectivities by a new oxidative coupling method.

A new oxidative coupling of unactivated terminal alkenes with amides using peroxides is described, in which mono- and difunctionalization of alkenes are selectively achieved. In this reaction with amides, the chemoselectivity toward the functionalization of the C(sp(3))-H bonds adjacent to the nitrogen atom or the functionalization of the carbonyl C(sp(2))-H bonds across alkenes relies on the reaction conditions.

Calixarene-modified chitosans (CTS–CA-I and CTS–CA-II) were first synthesized by the reaction of chitosan (CTS-NH2) with 1,3-bis-chloroethoxyethoxy-2,4-dihydroxy-p-tert-butylcalix[4]arene (CA-I) or its benzoyl derivative (CA-II). Their structures were characterized by infrared and X-ray diffraction spectroscopy and scanning electron microscopy (SEM). The adsorption of Ni2+, Cd2+, Cu2+, Pd2+, Ag+, and Hg2+ by CTS–CA-I and CTS–CA-II was studied and the thermodynamic parameter of two calixarene-modified chitosans toward Hg2+ was deduced. The adsorption properties of CTS–CA-I and CTS–CA-II were greatly varied compared with that CTS-NH2, especially with the adsorption capacity toward Ag+ and Hg2+, because of the presence of the calixarene moiety. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1139–1144, 2003

Since carbon-based structures of various dimensions, including one-dimensional (1D) carbon nanotubes, two-dimensional (2D) graphene and three-dimensional (3D) carbon foams, have attracted significant attention as microwave absorption fillers, we present an exceptional hetero-junction filler with a 1D–2D–1D feature, achieved by manipulating 2D graphene into 1D carbon fibers in the fiber-extruding process under the electric field. The as-fabricated 1D–2D–1D structural fillers exhibited much-improved dielectric properties and promoted microwave absorption performance in their composites, which is linked to the establishment of enhanced polarization capability, the generation of increased electric loss pathway and the creation of more favorable electromagnetic energy consumption conditions. The results suggest that employing 2D graphene in the 1D–2D–1D nanostructures played the critical role in tuning the electromagnetic response ability, because of its intrinsic electric advantages and dimensional features. To broaden the effective absorption bandwidth, periodic pattern-absorbing structures were designed, which showed combined absorption advantages for various thicknesses. Our strategy for fabricating 1D–2D–1D structural fillers illuminates a universal approach for manipulating dimensions and structures in the nanotechnology.

Based on ARM processor and WinCE embedded systems, a detector design is provided for some certain special equipment temperature controller, as well as the relevant hardware and software. In software design, the operating system is customized, driver for hardware is programmed and testing data real-time display is achieved through multi-threading technology with extra data saving and failure analysis functions, then the relationship between pulse frequency under test and detection opportunity is obtained. Experiment results show that the detector assumes good stability, high accuracy and convenient operation. The design ideas and engineering methods can be used for real-time physical parameters detecting of low-frequency pulse signal.

p-tert- Butylcalix[4]diazacrown-4 telomer, which contains hard and soft ion binding sites, was synthesized. It exhibited high selectivity toward cesium ions. The binding sites may complex alkali metal ions selectively.

Since manipulating electromagnetic waves with electromagnetic active materials for environmental and electric engineering is a significant task, here a novel prototype is reported by introducing reduced graphene oxide (RGO) interfaces in carbon fiber (CF) networks for a hierarchical carbon fiber/reduced graphene oxide/nickel (CF-RGO-Ni) composite textile. Upon charaterizations of the microscopic morphologies, electrical and magnetic properties, the presence of three-dimensional RGO interfaces and bifunctional nickel nanoparticles substantially influences the related physical properties in the resulting hierarchical composite textiles. Eletromagnetic interference (EMI) shielding performance suggests that the hierarchical composite textiles hold a strong shielding effectiveness greater than 61 dB, showing greater advantages than conventional polymeric and foamy shielding composites. As a polymer-free lightweight structure, flexible CF-RGO-Ni composites of all electromagnetic active components offer unique understanding of the multi-scale and multiple mechanisms in electromagnetic energy consumption. Such a novel prototype of shielding structures along with convenient technology highlight a strategy to achieve high-performance EMI shielding, coupled with a universal approach for preparing advanced lightweight composites with graphene interfaces.

Through the experiments of leaching and melting on the fly ash of medical wastes, the influence of leaching time, L/S, pH and grain size on the leaching characteristics of heavy metal and the effect of melting on the stabilization of fly ash are studied. Results show that, following the leaching time extending, the leaching concentrations of heavy metals and lixiviate toxicity of heavy metals increase in the fly ash. When the ratio of liquid and solid add, the leaching concentrations of heavy metals obviously become big, and the Cd's leaching concentration is the biggest, when the ratio of liquid and solid is 90, the Cd' s leaching ratio exceed the percent of 70. At the time pH is about 7, the leaching concentrations of heavy metals are the lowest. When the grain size is the bigger or little, the leaching concentrations of heavy metals are lower, however when the grain size is 250-900 microm, the concentrations are higher. After fly ash melt in the high temperature, the lixiviate toxicity of heavy metals greatly reduce, which explains that the effect of melting on heavy metals' stabilization is very good.

To investigate the time trends of cancer mortality among residents in Kaifeng county, Henan province.Data on cancer mortality from the vital registration system in Kaifeng county from 1988 to 2005 was analyzed. A total of 9543 death records (5974 males and 3567 females) due to malignant tumors were studied. A two-year-period age-specified standardized mortality rates were directly adjusted by the world standard population, and the annual percentage change (APC) of mortality were estimated by a linear logarithm regression.The crude cancer death rate for male was 95.09/100,000 and its age-standardized death rate was 117.41/100,000. While, the crude cancer death rate for female was 59.13/100,000 and the age-standardized death rate was 57.15/100,000. There was a significant growth tread for lung cancer (APC: 6.54%), liver cancer (5.07%) in males and breast cancer (7.04%) in females in the groups aged over 18. On the contrary, the decreasing treads for esophageal cancer in both of sexes (-7.09%, -13.53%) were also observed in this study. Meanwhile, there was no other significant changes in the trend, either in the tumor sites or mortality, was observed.In the past two decades, there has been a significant increasing trend for cancer mortality in Kaifeng county, of Henan Province. Hence, it is necessary to enhance epidemiological survey to identify risk factors at the earlier stages.

Cu-catalyzed synthesis of 3-etherified azaspiro[4.5]trienones from N-arylpropiolamides and ethers is presented using TBHP oxidant. This is achieved through C(sp3)–H functionalization, ipso-carbocyclization and dearomatization, and this method represents a new example of alkyne oxidative 1,2-difunctionalization with an ipso-aromatic carbon and a C(sp3)–H bond by simultaneously forming two new carbon–carbon bonds.