Three novel dendritic chitosan derivatives for inhibiting acid corrosion of petroleum pipelines

In the process of exploration and development of oil and gas fields, the acidic environment of oil reservoir, production and transport processes cause corrosion of pipelines and equipment, resulting in huge economic losses and production safety risks. Corrosion inhibitors were widely used in oil industry because of simple operation process and economical. In this study, three environmentally friendly corrosion inhibitors were synthesized based on the natural polysaccharide chitosan. Corrosion inhibition of three dendritic chitosan derivatives (We name them BH, CH and DH) on mild steel in 1 mol/L HCl solution with natural ventilation system was evaluated by weight loss experiment, electrochemical analysis and surface morphology characterization. The experimental results showed that when the three dendritic chitosan derivatives added in the corrosive medium were 500 mg L^(−1), the corrosion inhibition efficiencies were all more than 80%. Based on quantum chemical calculation, inhibition mechanisms of three dendritic chitosan derivatives were investigated according to molecular structures. The results showed that the benzene ring, Schiff base and N atom contained in the molecule were the active centers of electron exchange, which were more likely to form a film on the carbon steel surface, thereby slowing or inhibiting corrosion. The results also predicted the corrosion inhibition effect BH > DH > CH, which was consistent with the experimental conclusion.

Treatment of proximal humeral fractures accompanied by medial calcar fractures using fibular autografts:A retrospective,comparative cohort study

BACKGROUND Severe proximal humerus comminuted fractures are often accompanied by medial calcar comminuted fractures and loss of medial support,which are important factors that lead to internal fixation failure.The appropriate treatment for proximal humerus comminuted fractures has not been established.Therefore,this study assessed the outcomes of using a fibular autograft with locking plates to treat severe proximal humerus comminuted fractures.AIM To investigate the outcomes of using a fibular autograft with locking plates to treat severe proximal humerus comminuted fractures.METHODS This retrospective,comparative cohort study included two groups of patients.Group 1 comprised 22 patients and group 2 comprised 25 patients with complete follow-up data.Group 1 was treated with a fibular autograft with open reduction and locking plates to enable internal fixation.Group 2 was treated with open reduction and locking plates to enable internal fixation.The intraoperative blood loss volume from the shoulder wound,operative time,shoulder wound pain,bone fracture healing time,Constant-Murley score of the shoulder joint,preoperative Holden walking function score,Mallet score of the shoulder joint,and humeral neck-shaft angle during surgery of the two groups were compared,and the differences were analysed using an independent sample t-test.RESULTS Group 1 had a shorter mean operative time than group 2(2.25±0.30 h vs 2.76±0.44 h;P=0.000).Group 1 had a lower shoulder wound pain score on the first day after surgery than group 2(7.91±1.15 points vs 8.56±1.00 points;P=0.044).Group 1 had a shorter fracture healing time than group 2(2.68±0.48 mo vs 3.64±0.64 mo;P=0.000).Group 1 had higher Constant-Murley scores of the shoulder joint at 3,6,and 12 mo after surgery than group 2(76.64±4.02 points vs 72.72±3.02 points,86.36±3.53 points vs 82.96±3.40 points,and 87.95±2.77 points vs 84.68±2.63 points,respectively;P=0.000,0.002,and 0.000,respectively).Group 1 had higher Mallet scores of the shoulder joint at 3,6,and 12 mo after surgery than group 2(10.32±0.57 points vs 9.96±0.54 points,13.36±1.00 points vs 12.60±0.87 points,and 13.91±0.75 points vs 13.36±0.70 points,respectively;P=0.032,0.007,and 0.013,respectively).CONCLUSION Using locking plates with a fibular autograft can recreate medial support,facilitate fracture healing,and improve shoulder function;therefore,this may be an effective treatment option for severe proximal humerus comminuted fractures.

血压变异干预策略对高血压脑白质疏松、预后卒中及认知的影响

目的探讨血压变异性(BPV)干预策略对高血压脑白质疏松(LA)、预后卒中及认知的影响。方法前瞻性研究2013年1月—2016年12月郑州人民医院神经内科就诊并最终纳入统计的高血压患者269例。BPV以血压标准差(SD)、变异系数(CV)表示。其中无或轻度LA组定义为对照组,中重度LA组定义为病变组。采用多因素Logistic回归分析BPV与LA的关系。入院后给予不同类别降压药物,同时,采用简明精神量表(MMSE)进行认知功能状态评分。1年后再次复查患者BPV及LA程度。分析不同降压药物对BPV、LA及1年内卒中事件和认知功能变化的影响。结果①病变组收缩压CV、收缩压SD、杓型分型与对照组比较,差异有统计学意义(P<0.05)。②较高收缩压SD、非杓型特点为LA的危险因素。[O^R=2.168(95%CI:1.120,4.195),P=0.022;O^R=2.764(95%CI:1.405,5.437),P=0.003]。③氨氯地平组用药后中重度LA比例、卒中事件发生率较依那普利及美托洛尔组降低(P<0.05);用药后氨氯地平、依那普利及美托洛尔组的SD分别为(13.756±2.919)、(14.919±3.037)和(15.433±2.962)(P<0.05);用药后氨氯地平、依那普利及美托洛尔组的MMSE评分分别为(27.484±2.267)、(26.575±2.488)和(26.032±3.113)(P<0.05)。结论收缩压SD及非杓型特点是预测LA较好且简易的指标,钙离子拮抗剂或长效降压药物可降低血压变异性,是预防LA、减少卒中及认知功能减退的有效措施。

Dynamic mass variation and multiphase interaction among steel, slag, lining refractory and nonmetallic inclusions: Laboratory experiments and mathematical prediction

The mass transfer among the multiphase interactions among the steel, slag, lining refractory, and nonmetallic inclusions during the refining process of a bearing steel was studied using laboratory experiments and numerical kinetic prediction. Experiments on the system with and without the slag phase were carried out to evaluate the influence of the refractory and the slag on the mass transfer. A mathematical model coupled the ion and molecule coexistence theory, coupled-reaction model, and the surface renewal theory was established to predict the dynamic mass transfer and composition transformation of the steel, the slag, and nonmetallic inclusions in the steel. During the refining process,Al_(2)O_(3) inclusions transformed into Mg O inclusions owing to the mass transfer of [Mg] at the steel/refractory interface and(Mg O) at the slag/refractory interface. Most of the aluminum involved in the transport entered the slag and a small part of the aluminum transferred to lining refractory, forming the Al_(2)O_(3) or Mg O·Al_(2)O_(3). The slag had a significant acceleration effect on the mass transfer. The mass transfer rate(or the reaction rate) of the system with the slag was approximately 5 times larger than that of the system without the slag. In the first 20 min of the refining, rates of magnesium mass transfer at the steel/inclusion interface, steel/refractory interface, and steel/slag interface were x, 1.1 x, and 2.2 x,respectively. The composition transformation of inclusions and the mass transfer of magnesium and aluminum in the steel were predicted with an acceptable accuracy using the established kinetic model.

Lamb’s tripe extract and vitamin B12 capsule plus celecoxib reverses intestinal metaplasia and atrophy:A retrospective cohort study

BACKGROUND Chronic atrophic gastritis(AG)with intestinal metaplasia(IM)significantly increases the risk of gastric cancer.Some medicines have showed definite therapeutic effects in AG and IM regression.AIM To validate the efficacy of Lamb’s tripe extract and vitamin B12 capsule(LTEVB12)initial therapy and celecoxib rescue therapy for IM and AG.METHODS A total of 255 patients were included to receive LTEVB12 initial therapy(2 capsules each time,three times daily for 6 mo)in hospital in this study.The patients with failure of IM regression continued to receive celecoxib rescue therapy(200 mg,once daily for 6 mo).After each therapy finished,the patients underwent endoscopy and biopsy examination.The regression efficiency was assessed by the operative link on gastritis assessment(OLGA)and the operative link on the gastric intestinal metaplasia assessment(OLGIM)staging system.Logistic regression analysis was applied to identify factors associated with the curative effect.RESULTS For LTEVB12 initial therapy,the reversal rates of IM and AG were 52.95%and 48.24%,respectively.Analogously,for celecoxib rescue therapy,the effective rates for IM and AG were 56.25%and 51.56%,respectively.The IM regression rate of complete therapy was up to 85.03%.In different OLGA and OLGIM stages of IM patients,therapeutic efficiency showed a significant difference in each group(P<0.05).For both therapies,patients with high stages(III or IV)of both the OLGA and OLGIM evaluation systems showed a higher IM or AG regression rate than those with low stages(I or II).Among patients with high stages(OLGIM III and IV),the IM regression rate was above 70%for each therapy.Eating habits,fresh vegetable intake,and high-salt diet were identified as independent factors for the IM reversal effect of LTEVB12 therapy,especially high-salt diet(odds ratio=1.852,P<0.05).CONCLUSION Monotherapy could reverse IM and AG.LTEVB12 initial therapy and celecoxib rescue therapy significantly increase the regression effect.IM may not be the point of no return among gastric precancerous lesions.

Influence of CXCR4/SDF-1 axis on E-cadherin/β-catenin complex expression in HT29 colon cancer cells

AIM： To study the influence of CXCR4/stromal cell- derived factor-1 （SDF-1） axis on E-cadherin/β-catenin complex expression in HT29 colon cancer ceils and its underlying mechanisms. METHODS： Effect of SDF-1 on E-cadherin/β-catenin expression was detected by immunocytochemistry. E-cadherin and/3-catenin mRNA expression levels were measured by reverse transcriptase-polymerase chain reaction. SDF-l-induced phosphorylation of phosphati- dylinositol 3-kinase （PI3K）/AKT and β-catenin was detected by Western blotting. RESULTS： The E-cadherin and β-catenin mRNA ex-pression levels in HT29 cells were lower 48 h after incubated with SDF-1 at the concentrations of 20 and 40 ng/mL （P 〈 0.05）. SDF-l-induced significant phosphorylation of PI3K/AKT and β-catenin. AMD3100 and LY294002 inhibited the phosphorylation of PI3K/AKT and β-catenin. CONCLUSION： SDF-1 down-regulates the E-cadherin/ β-catenin complex expression in HT29 cells by decreasing mRNA synthesis and increasing β-catenin phosphorylation.

Gas–liquid mass transfer and flow phenomena in the Peirce–Smith converter: a water model study

A water model with a geometric similarity ratio of 1：5 was developed to investigate the gas-liquid mass transfer and flow charac- teristics in a Peirce-Smith converter. A gas mixture of CO2 and Ar was injected into a NaOH solution bath. The flow field, volumetric mass transfer coefficient per unit volume （Ak/V; where A is the contact area between phases, V is the volume, and k is the mass transfer coeffi- cient）, and gas utilization ratio （t/） were then measured at different gas flow rates and blow angles. The results showed that the flow field could be divided into five regions, i.e., injection, strong loop, weak loop, splashing, and dead zone. Whereas the Ak/V of the bath increased and then decreased with increasing gas flow rate, and n steadily increased. When the converter was rotated clockwise, both Ak/F and t/increased. However, the flow condition deteriorated when the gas flow rate and blow angle were drastically increased. Therefore, these para- meters must be controlled to optimal conditions. In the proposed model, the optimal gas flow rate and blow angle were 7.5 m3.h-1 and 10°, respectively.

Gas–liquid mass transfer and flow phenomena in a peirce–smith converter: A numerical model study

A numerical model was established to simulate the flow field in a Peirce–Smith converter bath, which is extensively adopted in copper making. The mean phase and velocity distribution, circular area, and mean wall shear stress were calculated to determine the optimal operation parameter of the converter. The results showed that the slag phase gathered substantially in the dead zone. The circular flow was promoted by increasing the gas flow rate, Q, and decreasing the nozzle height, h. However, these operations significantly aggravate the wall shear stress. Reducing the nozzle diameter, d, increases the injection velocity, which may accelerate the flow field. However, when the nozzle diameter has an interval design, the bubble behaviors cannot be combined, thus, weakening the injection efficiency. Considering the balance between the circular flow and wall shear stress in this model, the optimal operation parameters were Q = 30000–35000 m^3/h, h = 425–525 mm, and d = 40 & 50 mm.

Water model experiments of multiphase mixing in the top-blown smelting process of copper concentrate

We constructed a 1：10 cold water experimental model by geometrically scaling down an Isa smelting furnace. The mixing processes at different liquid heights, lance diameters, lance submersion depths, and gas flow rates were subsequently measured using the conductivity method. A new criterion was proposed to determine the mixing time. On this basis, the quasi-equations of the mixing time as a function of different parameters were established. The parameters of the top-blown smelting process were optimized using high-speed photography. An excessively high gas flow rate or excessively low liquid height would enhance the fluctuation and splashing of liquid in the bath, which is unfavorable for material mixing. Simultaneously increasing the lance diameter and the lance submersion depth would promote the mixing in the bath, thereby improving the smelting efficiency.

基于物联网技术的动态GRNN模型的液压系统故障检测研究

液压系统因其独特的特性,在各个领域有着广泛的应用。液压设备的运行安全与状态监测是生产中的一项重要内容。由于液压系统的所有部件都在封闭油路中工作,故障源的定位比较困难。为了解决这个问题,本文提出了一种基于物联网技术的动态故障诊断方法GRNN模型的基于物联网的智能控制,利用无线传感器网络技术在分布式液压设备中各参数的实时测量和控制,远程数据共享、故障信号的采集输入GRNN模型故障观察器,检测阈值,通过实验模拟准确诊断系统故障。实验表明,该方法可以有效地应用于过程生产液压系统中,保证系统的正常运行,降低设备故障率,提高生产效率。

A coupled model on fluid flow,heat transfer and solidification in continuous casting mold

Fluid flow, heat transfer and solidification of steel in the mold are so complex but crucial, determining the surface quality of the continuous casting slab. In the current study, a 2D numerical model was established by Fluent software to simulate the fluid flow, heat transfer and solidification of the steel in the mold. The VOF model and k-ε model were applied to simulate the flow field of the three phases(steel, slag and air), and solidification model was used to simulate the solidification process. The phenomena at the meniscus were also explored through interfacial tension between the liquid steel and slag as well as the mold oscillation. The model included a 20 mm thick mold to clarify the heat transfer and the temperature distribution of the mold. The simulation results show that the liquid steel flows as upper backflow and lower backflow in the mold, and that a small circulation forms at the meniscus. The liquid slag flows away from the corner at the meniscus or infiltrates into the gap between the mold and the shell with the mold oscillating at the negative strip stage or at the positive strip stage. The simulated pitch and the depth of oscillation marks approximate to the theoretical pitch and measured depth on the slab.

Dissolution behaviors of rare earth elements in phosphoric acid solutions

In order to provide practical fundamental data for rare-earth elements （REEs） recovery from phosphoric acid and to betterunderstand REEs behavior during the phosphoric acid evaporation process, the solubilities of REEs in phosphoric acid with variousconcentrations of phosphorus at different temperatures were measured. A simple linear model between REEs solubility andphosphoric acid concentration is built and the experimental data are found to fit it very well （R2〉0.94）. Hydrogen-ion concentration isfound to be the predominant factor controlling the solubility of REEs in phosphoric acid. In addition, the solubility of REEs inphosphoric acid is found to sharply decrease with increasing temperature, which can be attributed to the increase of the Gibbs energyof the REEPO4 dissolution reaction or the restraint of the disassociation of phosphoric acid molecules owing to the elevatedtemperature.

Quantitative modeling, optimization, and verification of ^(63)Nipowered betavoltaic cells based on three-dimensional ZnO nanorod arrays

Betavoltaic cells(BCs)are promising self-generating power cells with long life and high power density.However,the low energy conversion efficiency(ECE)has limitations in practical engineering applications.Widebandgap semiconductors(WBGSs)with three-dimensional(3-D)nanostructures are ideal candidates for increasing the ECE of BCs.This paper proposes hydrothermally grown ZnO nanorod arrays(ZNRAs)for ^(63)Ni-powered BCs.A quantitative model was established for simulation using the parameter values of the dark characteristics,which were obtained from the experimental measurements for a simulated BC based on a Ni-incorporated ZNRAs structure.Monte Carlo(MC)modeling and simulation were conducted to obtain the values of the β energy deposited in ZNRAs with different nanorod spacings and heights.Through the simulation and optimization of the 3-D ZNRAs and 2-D ZnO bulk structures,the performance of the ^(63)Ni-powered BCs based on both structures was evaluated using a quantitative model.The BCs based on the 3-D ZNRAs structure and 2-D ZnO bulk structure achieved a maximum ECE of 10.1%and 4.69%,respectively,which indicates the significant superiority of 3-D nanostructured WBGSs in increasing the ECE of BCs.

Boron separation from Si–Sn alloy by slag treatment

This study investigates a purification process for metallurgical-grade silicon(MG-Si) in which Si is alloyed with tin(Sn) and Ca O–Si O_2–Ca Cl_2 slag is used to remove boron(B) impurity. Acid leaching was performed to remove the Sn phase after slag refining to recover high-purity Si from the Si–Sn alloy. The effect of refining time was investigated, and acceptable refining results were realized within 15 min. The effects of slag composition and Sn content on the removal of B were also studied. The results indicate that increasing Sn content favors B removal. With the increase of Sn to 50% of the alloy, the final B content decreased to 1.1 × 10^(-4) wt%, 93.9% removal efficiency.

Blood tests for prediction of deep endometriosis:A case-control study

BACKGROUND Deep endometriosis(DE)is the most aggressive subtype of endometriosis.The diagnosis may be challenging,and no biomarkers that can discriminate women with DE from those without DE have been developed.AIM To evaluate the role of blood hemostatic parameters and inflammatory indices in the prediction of DE.METHODS This case-control study was performed at the Women’s Hospital,Zhejiang University School of Medicine between January 2015 and December 2016.Women with DE and women with benign gynecologic disease(control group)eligible for gynecological surgery were enrolled.Routine plasma hemostatic parameters and inflammatory indices were obtained before surgery.Univariate and multivariate analysis were performed.Receiver operating characteristic(ROC)curves were generated,and areas under the curve(AUC)were calculated to assess the predictive values of the selected parameters.RESULTS A total of 126 women were enrolled,including 31 with DE and 95 controls.Plasma fibrinogen(Fg,P<0.01),international normalized ratio(P<0.05),and Creactive protein levels(P<0.01)were significantly higher in women with DE compared with controls.Plasma hemoglobin(HB)levels(P<0.05)and shortened thrombin time(P<0.05)were significantly lower in women with DE than in controls.Plasma Fg levels[adjusted OR(aOR)2.12,95%confidence interval(CI):1.31-3.75]and plasma HB levels(aOR 0.48,95%CI:0.29-0.78)were significantly associated with DE(both P<0.05).ROC analysis showed that the diagnostic value of Fg or HB alone for DE was limited.The AUC of the combination of both markers as a dual marker index was 0.773 with improved sensitivity(67.7%)and specificity(78.9%)at cutoffs of 3.09 g/L and 126 g/L,respectively.CONCLUSION The combination of Fg and HB was a reliable predictor of DE.A larger study is needed to confirm the findings.

Preparation of β-SiC by combustion synthesis in a large-scale reactor

The feasibility of 5 kg β-SiC synthesized in one batch was demonstrated through igniting the mixture of Si, C-black and polytetrafluoroethylene （PTFE） under different nitrogen pressures. The effect of experimental parameters, including the contents of PTFE, nitrogen pressure, preheating, and raw materials distribution forms were investigated. The results show that the products are β-SiC with equiaxed grains. The average grain size is less than 200 nm. The powders loaded loosely promote reaction heat dispersing, resulting in small grains. High purity β-SiC powders are obtained when the PTFE content is as low as 5wt%, which simplifies the process and decreases the cost effectively. The ceramic sintered from the obtained β-SiC powders presents the hardness of 22.20 GPa, the bending strength as high as 715.15 MPa and the fracture toughness of 8.179 MPa·m^1/2, which are higher than those of ceramics fabricated with α-SiC produced by combustion synthesis.

Effect of oxide inclusions on MnS precipitates and tensile mechanical property of high-strength low-alloy steel

The key role of oxide inclusions on the microstructure and mechanical property of a high-strength low-alloy steel was investigated.The field emission scanning electron microscope equipped with energy-dispersive spectrometry was used to characterize MnS precipitates.Oxide inclusions play an important role in the shape control of MnS precipitates.More oxides fovored to decrease the size and the aspect ratio of MnS precipitates.With less oxide inclusions in the steel,approximately over 16.7%MnS precipitates were with aspect ratio a>5 and pure MnS precipitates accounted for 75.9%in number.However,with more oxide inclusions in the steel,only 7.4%MnS precipitates were with a>5 and pure MnS precipitates accounted for 60.1%in number.Refinement of MnS by oxide inclusions improved the strength and inhibited the anisotropy.More oxide inclusions in the steel increased the yield strength and tensile strength of the steel in both longitudinal and transverse directions,and lowered the anisotropy of the mechanical property.

Water modeling on fluid flow and mixing phenomena in a BOF steelmaking converter

A 1∶8 physical water model was constructed to investigate the fluid flow and mixing phenomena in the basic oxygen furnace(BOF)converter.The particle image velocimetry was employed to measure the velocity distribution of the bath and the high-speed camera was applied to capture the cavity shape in the combined blowing BOF converter.The mixing time for varied operating conditions was measured by the stimulus-response approach.The cavity depth increased with the decrease in the lance height and the increase in the top gas flow rate while the bottom blowing gas had little influence on the cavity depth.The minimum cavity depth was obtained under the condition of a 69.8 m^(3)/h top gas flow rate,a 287.5 mm lance height and a 0.93 m^(3)/h bottom blowing gas flow rate,which was 161.2 mm.The mixing time decreased as the lance height decreased and the top blowing gas flow rate increased.The mixing time was first decreased and then increased with the increase in the bottom gas flow rate.With the condition of 69.8 m^(3)/h gas flow rate of top blowing,the 287.5 mm lance height and the 0.93 m^(3)/h gas flow rate of bottom blowing,the mixing time in the converter was 48.65 s.The empirical formula between the stirring power and the mixing time in the converter was calculated.

Effect of lanthanum on inclusions in non-oriented electrical steel slabs

The effect of lanthanum on the characteristics of inclusions in the slab of non-oriented electrical steels was investigated through industrial trials and thermodynamic analysis.The number,size,and chemical composition of inclusions in the surface,one-quarter of thickness and the center of slabs with and without lanthanum addition were statistically analyzed using an automatic inclusion analysis system.In the lanthanum-free slab,inclusions were predominately MgO.Al_(2)O_(3),MgO,and AlN as well as a small number of Al_(2)O_(3)-MgO-CaO and MgS.The number densities of oxide inclusions and AlN decreased from the surface to the center of the slab,which was ascribed to the difference in cooling intensity during the continuous casting.In the steel with lanthanum addition,inclusions were modified into LaAlO_(3) and La_(2)O_(2)S and gradually transformed into dual-phase MgO-La_(2)S3 with an increasing distance from the slab surface due to the reaction between the lanthanum-containing inclusion and the steel matrix.The uneven distribution of oxide inclusions along the thickness of the slab was eliminated in the lanthanum-bearing slab because the dissolved oxygen was remarkably decreased by lanthanum.Lanthanum-bearing inclusions were more likely to agglomerate AlN by inducing the heterogeneous nucleation of AlN on their surface,while small-size MgO.Al_(2)O_(3) inclusions hardly showed a coarsening effect on the size of AlN.

Perioperative complication incidence and risk factors for retroperitoneal neuroblastoma in children:analysis of 571 patients

Background Surgery plays an important role in the treatment of neuroblastoma.Perioperative complications may impact the course of neuroblastoma treatment.To date,comprehensive analyses of complications and risk factors have been lacking.Methods Patients with retroperitoneal neuroblastoma undergoing tumor resection were retrospectively analyzed between 2014 and 2021.The data collected included clinical characteristics,operative details,operative complications and postopera-tive outcomes.Risk factors for perioperative complications of retroperitoneal neuroblastoma were analyzed.Results A total of 571 patients were enrolled in this study.Perioperative complications were observed in 255(44.7%)patients.Lymphatic leakage(28.4%),diarrhea(13.5%),and injury(vascular,nerve and organ;7.5%)were the most frequent compli-cations.There were three operation-related deaths(0.53%):massive hemorrhage(n=1),biliary tract perforation(n=1)and intestinal necrosis(n=1).The presence of image-defined risk factors(IDRFs)[odds ratio(OR)=2.09,P<0.01],high stage of the International Neuroblastoma Risk Group staging system(INRGSS)(OR=0.454,P=0.04),retroperitoneal lymph node metastasis(OR=2.433,P=0.026),superior mesenteric artery encasement(OR=3.346,P=0.003),and inferior mesenteric artery encasement(OR=2.218,P=0.019)were identified as independent risk factors for perioperative complications.Conclusions Despite the high incidence of perioperative complications,the associated mortality rate was quite low.Perio-perative complications of retroperitoneal neuroblastoma were associated with IDRFs,INRGSS,retroperitoneal lymph node metastasis and vascular encasement.Patients with high-risk factors should receive more serious attention during surgery but should not discourage the determination to pursue total resection of neuroblastoma.