Predictive value of positive lymph node ratio in patients with locally advanced gastric remnant cancer

BACKGROUND Traditional lymph node stage(N stage)has limitations in advanced gastric remnant cancer(GRC)patients;therefore,establishing a new predictive stage is necessary.AIM To explore the predictive value of positive lymph node ratio(LNR)according to clinicopathological characteristics and prognosis of locally advanced GRC.METHODS Seventy-four patients who underwent radical gastrectomy and lymphadenectomy for locally advanced GRC were retrospectively reviewed.The relationship between LNR and clinicopathological characteristics was analyzed.The survival analysis was performed using Kaplan-Meier survival curves and Cox regression model.RESULTS Number of metastatic LNs,tumor diameter,depth of tumor invasion,Borrmann type,serum tumor biomarkers,and tumor-node-metastasis(TNM)stage were correlated with LNR stage and N stage.Univariate analysis revealed that the factors affecting survival included tumor diameter,anemia,serum tumor biomarkers,vascular or neural invasion,combined resection,LNR stage,N stage,and TNM stage(all P<0.05).The median survival time for those with LNR0,LNR1,LNR2 and LNR3 stage were 61,31,23 and 17 mo,respectively,and the differences were significant(P=0.000).Anemia,tumor biomarkers and LNR stage were independent prognostic factors for survival in multivariable analysis(all P<0.05).CONCLUSION The new LNR stage is uniquely based on number of metastatic LNs,with significant prognostic value for locally advanced GRC,and could better differentiate overall survival,compared with N stage.

Effect of the number of positive lymph nodes and lymph node ratio on prognosis of patients after resection of pancreatic adenocarcinoma

BACKGROUND： The prognostic factors related to lymph node involvement [lymph node status, the number of positive lymph nodes, lymph node ratio （LNR）] and the number of nodes evaluated in patients with pancreatic adenocarcinoma after pancreatectomy are poorly defined. METHODS： A total of 167 patients who had undergone resection of pancreatic adenocarcinoma from February 2010 to August 2011 were included in this study. Histological examination was performed to evaluate the tumor differentiation and lymph node involvement. Univariate and multivariate analyses were made to determine the relationship between the variables related to nodal involvement and the number of nodes and survival. RESULTS： The median number of total nodes examined was 10 （range 0-44） for the entire cohort. The median number of total nodes examined in node-negative （pN0） patients was similar to that in node-positive （pN1） patients. Patients with pN1 diseases had significantly worse survival than those with pN0 ones （P=0.000）. Patients with three or more positive nodes had a poorer prognosis compared with those with the negative nodes （P=0.000）. The prognosis of the patients with negative nodes was similar to that of those with one to two positive nodes （P=0.114）. The median survival of patients with an LNR ≥0.4 was shorter than that of patients with an LNR 〈0.4 in the pN1 cohort （P=0.014）. No significance was found between the number of total nodes examined and the prognosis, regardless of the cutoff of 10 or 12 and in the entire cohort or the pN0 and pN1 groups. Based on the multivariate analysis of the entire cohort and the pN1 group, the nodal status, the number of positive nodes and the LNR were all associated with survival. CONCLUSIONS： In addition to the nodal status, the number of positive nodes and the LNR can serve as comprehensive factors for the evaluation of nodal involvement. This approach may be more effective for predicting the survival of patients with pancreatic adenocarcinoma after pancreatectomy.

The Effects of the Geometry of a Current Collector with an Equal Open Ratio on Output Power of a Direct Methanol Fuel Cell

The open ratio of a current collector has a great impact on direct methanol fuel cell(DMFC)performance.Although a number of studies have investigated the influence of the open ratio of DMFC current collectors,far too little attention has been given to how geometry(including the shape and feature size of the flow field)affects a current collector with an equal open ratio.In this paper,perforated and parallel current collectors with an equal open ratio of 50%and different feature sizes are designed,and the corresponding experimental results are shown to explain the geometry effects on the output power of the DMFC.The results indicate that the optimal feature sizes are between 2 and 2.5 mm for both perforated and parallel flow field in the current collectors with an equal open ratio of 50%.This means that for passive methanol fuel cells,to achieve the highest output power,the optimal feature size of the flow field in both anode and cathode current collectors is between 2 and 2.5 mm under the operating mode of this experiment.The effects of rib and channel position are also investigated,and the results indicate that the optimum pattern depends on the feature sizes of the flow field.

Influence of Inner/Outer Stator Pole Ratio and Relative Position on Electromagnetic Performance of Partitioned Stator Switched Flux Permanent Magnet Machines

Based on the 6-pole outer stator(armature winding-stator),the influence of inner(permanent magnet-stator)/outer stator pole ratio n(n=NIS/NOS),stator relative positions and rotor pole number combinations on electromagnetic performance of partitioned stator switched flux permanent magnet(PM)machines(PS-SFPMMs)is investigated in this paper.Since the armature windings and PMs are located in two separated stators and PMs are stationary,PS-SFPMMs have high fault tolerance capabilities.To maximize the torque performance,the PM of inner stator pole should be aligned with outer stator pole when n is odd while the iron rib of inner stator pole should be aligned with outer stator pole when n is even.No matter what n is selected,the rotor pole number NR can be any integers except the phase number and its multiples.The analysis results indicate that the optimal NR is closed to(NIS+NOS)/2 and it is odd when n is odd while it is even when n is even.Meanwhile,symmetrical phase back-EMF waveform will be obtained when the ratio of Min(NOS,NIS)to the greatest common divisor of Min(NOS,NIS)and NR is even.Based on the optimal rotor pole numbers for 6-pole outer stator with different n and corresponding optimal relative position together with same rated copper loss,the average torque is improved by 18.4%,25.1%and 25.7%respectively in PS-SFPMMs with n equal to 2,3 and 4 when compared with PS-SFPMM with n equal to 1.The analyses are validated by experiment results of the prototype machine.

The evolution characteristics of positive and negative earthquakes before strong quakes in Kanto area and the Hyugo earthquake in Japan

This paper studies the evolution charateristics of positive and negative quakes before Hyugo earthquake of M =7.2 and several strong quakes in Kanto area in Japan.The results show that the earthquakes over a certain megnitude are mainly positive ones a certain time before the main shock in or near the focal regions of most strong quakes,and form a concentratingintervals of positive quakes,The main quakes generally locate in or near the areas of positive quake distribution.Negative quakes often occur several months before the main shocks (not excluding positive ones), with the decrease of LURR (Loading/Unloading Response Ratio) values.It possibly shows that earthquake generating process has come to a short term stage.These characteristics may help to predict the time and location of the future earthquakes,and have been applied to the preliminary prediction of the time and the location of the earthquake of M =6.6 on Sep.11,1996 in Kanto area.

GNSS基准站信噪比联合卫星系统综合定权的手机RTK定位

随着智能手机芯片和天线性能的不断提升,基于手机的高精度定位逐渐引起学术界和工业界的广泛关注.相较于单点定位,实时动态(real-time kinematic,RTK)定位通常表现出更高的定位性能.然而,目前对于手机RTK定位的随机模型的研究仍相对较少.因此,文中以小米8为例,重点探讨了智能手机在多系统RTK定位情境下的随机模型.研究结果表明:不同系统的卫星伪距噪声存在显著差异,而相位噪声的差异则较小.基于此,本文提出了一种基站信噪比联合卫星系统间综合定权的随机模型.相对于传统的信噪比模型更准确地考虑了不同系统之间的权重分配.并在开阔和遮挡条件下进行了静态和动态实验.结果表明:相比于传统的信噪比模型,新模型在静态开阔、静态遮挡、动态开阔和动态遮挡下三维方向的RTK定位精度分别提升了18.7%、18.3%、3.3%和4.6%.

管理者超额积极情绪对企业风险承担的影响研究

选取我国2010-2020年A股非金融上市公司年报作为研究样本,构建管理者超额积极情绪指标,研究管理者超额积极情绪对企业风险承担的影响以及相应的影响机制,并探究股权激励在其中的调节作用。实证研究表明,管理者超额积极情绪能促进企业风险承担;股权激励在其中起到正向调节作用,会促进管理者超额积极情绪对企业风险承担的正向影响。作用机制检验表明,管理者超额积极情绪主要通过增加债务融资和减少融资约束程度促进企业风险承担。进一步分析表明,管理者超额积极情绪对企业风险承担的促进作用在非国有企业、高机构投资者持股比例显著。

妊娠早、中期妇女尿碘/尿肌酐比值与亚临床甲状腺功能减退症合并自身抗体阳性的相关性

目的:探讨妊娠早、中期妇女尿碘/尿肌酐比值(UIC/UCr)与亚临床甲状腺功能减退症(SCH)合并自身抗体阳性的相关性。方法:回顾性选取2018年1月—2021年6月贵阳市第一人民医院进行孕检的妊娠早、中期SCH孕妇作为研究对象,依据甲状腺自身抗体检测结果,将其分为:妊娠早、中期甲状腺抗体阳性组;妊娠早、中期甲状腺抗体阴性组;另选取同时期进行检查的妊娠早、中期健康孕妇作为对照组,每组各100例,共计300例,观察甲状腺过氧化物酶抗体(TPOAb)、甲状腺球蛋白抗体(TgAb)、UIC/UCr、促甲状腺激素(TSH)、游离三碘甲状腺原氨酸(FT3)、血清游离甲状腺素(FT4)等指标。结果:妊娠早期三组孕妇一般临床资料比较,差异无统计学意义(P>0.05),妊娠中期三组孕妇收缩压(SBP)、舒张压(DBP)比较,差异有统计学意义(F=7.024、11.357,P<0.05);UIC/UCr分析显示,与其他组别比较,妊娠早、中期阳性组孕妇均值和百分位分布数值最低;甲状腺激素及抗体水平比较,除FT3和FT4外,妊娠早、中期阳性组孕妇UIC/UCr、TPOAb、TgAb和TSH水平与健康组和阴性组比较,差异有统计学意义(F=71.710、279.102、130.017、275.949、22.991、220.702、288.882、184.459,P<0.001);相关性分析结果显示,UIC/UCr与TSH、TgAb、TPOAb水平呈负相关;多元线性回归分析结果发现,UIC/UCr、TSH是TPOAb、TgAb的主要影响因素。结论:妊娠早、中期SCH合并自身抗体阳性孕妇,UIC/UCr显著偏低且与TPOAb、TgAb关系密切,建议在临床中加强UIC/UCr指标观察。

基于RSSR融合RNGO-Elman神经网络的室内可见光定位

针对动态环境下基于接收信号强度的传统可见光定位方法定位精度低、稳定性差等问题,提出一种基于接收信号强度比的改进北方苍鹰算法(NGO)优化Elman神经网络(RNGOElman)的室内可见光定位系统。提出选择一个辅助参考点,将待测参考点与辅助参考点的接收信号强度比值和接收机的真实位置作为训练集数据,建立不受动态环境影响的指纹数据库。针对NGO算法收敛速度慢、容易陷入局部最优等问题,利用折射反向学习策略初始化种群,增加种群多样性,引入非线性权重因子来加快收敛速度,避免陷入局部最优。使用优化后的NGO算法来优化Elman神经网络的初始权值和阈值,构建RNGO-Elman动态定位预测模型。仿真结果表明,在4m×4m×3m的实验空间下,优化后的RNGO-Elman定位模型平均定位误差为1.34cm,定位精度相较于Elman定位算法、NGO-Elman定位算法分别提高了82%,21%。在LED发射功率波动时,基于RSSR的RNGO-Elman定位误差为1.29cm,1.38cm。所提可见光定位方法具有定位精度高、定位性能稳定等优点。

智能手机GNSS观测数据筛选方法及精度分析

通过分析智能手机的信噪比波动特性,提出将截止信噪比与剔除数据占比相结合进行数据筛选的质量控制方法,通过设置不同的数据筛选方案,对小米8和华为Mate 20智能手机在静态、动态观测中采集的数据进行对比分析。实验结果表明:智能手机端不同卫星的信噪比波动周期和范围均不同,存在独立性,且高度角和信噪比的相关性弱于测量型接收机,因此根据截止信噪比来筛选数据更为合理。设置截止信噪比的剔除数据占比在5%~10%,对智能手机的定位精度提升最佳,此时截止信噪比约为25 dB-Hz。相比传统设置15°卫星截止高度角的方法,所提方法的东、北、天向精度在静态中约提升25%、10%和20%,动态中约提升30%、20%和5%。

基于波噪比的高速铁路钢轨波磨快速检测方法

为实现高速铁路钢轨波磨里程覆盖式、高频次、快速测量,提出基于波噪比的钢轨波磨快速检测方法。采用便携式添乘仪检测高速列车车体振动和车内噪声数据,提出基于车体纵向加速度进行数值积分来计算列车速度和里程,采用曲线地段车体摇头角速度里程与台账里程的偏差值修正速度积分误差。利用提取的里程修正后车厢噪声数据与钢轨波磨对应的400~700 Hz频带成分,计算频带能量占噪声总能量的比值,并获取波噪比超限时的钢轨波磨波长和里程。结合高速列车实测数据分析,研究结果表明:速度修正后列车定位里程最大误差为87 m,对波磨比大于0.3的线路区段进行钢轨波磨波形测量和轴箱加速度振动能量比分析,钢轨波磨波长范围为53~57 mm,实测波长为53 mm,验证了该方法的正确性,为高速铁路钢轨波磨的快速测量提供技术支撑。

配网线路无人机智能剪线机构设计与优化

配网线路无人机智能剪线机构在废弃配网线路拆除过程中起着至关重要的作用。文中以某卸电剪线机构为研究对象,简化机构模型,明确优化目标,研究剪线过程中的横向振动与纵向振动随两轴交点位置与长轴之比及长短轴长度之比的变化规律,并以横向振动与纵向振动的幅度最小为优化目标,得到位比与轴比最优点,并得出了剪线作业时的横向振动与纵向振动与位比和轴比的变化关系。研究结果表明:位比不变时,横向振幅与纵向振幅随轴比的增大先减小后增大且横向振幅的降速慢于纵向振幅降速,横向振幅升速快于纵向振幅升速;轴比不变时,横向振幅与纵向振幅随轴比的增大而减小,且纵向振幅的降速与升速均快于横向振幅;卸电剪线机构的最优位比和轴比为0.35和2.3。

GPS/QZSS在亚太地区实时相对定位性能分析

利用BNC(BKG NTRIP client)传输的实时观测数据,从可见卫星数、位置精度因子(position dilution of precision, PDOP)、多路径效应、信噪比和实时相对定位精度等方面对GPS和QZSS在亚太地区的定位性能进行评估和分析。结果表明,QZSS与GPS组合后,可见卫星数增加,卫星几何构型更好,可提高定位精度的可用性和可靠性;QZSS卫星多路径效应的变化规律与GPS卫星一致,且QZSS卫星各频点的多路径误差大多小于GPS卫星;GPS和QZSS卫星各频点的信噪比随高度角变化趋势基本相同;在N、E、U方向上,GPS/QZSS组合的实时相对定位精度比GPS有所提升。

CNC锻床伺服系统三环PSO-PID整定控制机电耦合研究

数控(CNC)锻冲床进给伺服系统控制性能受到机电系统力、热、磨损的共同影响,在加工过程中会产生动态误差。为全面分析数控锻冲床进给伺服系统动态误差变化,设计了一种精度三环控制系统,建立了传动机电耦合模型,并开展仿真分析。从进给伺服系统实际运行工况区间考虑,分析系统动态误差。研究结果表明:增大工况载荷后,形成了更大惯量比伺服系统,系统获得了更大的超调量,引起响应时间增加。进给伺服系统产生了5.5mm位置偏差,在惯量比4.15下获得了最优定位精度。相比较PID控制,采用PSO-PID方法处理时可以降低误差,获得了最明显的效果。该研究有助于提高数控锻冲床进给伺服系统位置控制精度,为后续的加工质量优化奠定一定的理论基础。

基于级数展开的位置误差加权定位方法

随着对海洋探索的愈加深入,对水下目标探测能力的要求也愈发严格。针对噪声干扰严重时算法性能大幅度下降的问题,文章主要研究仅利用分布式矢量水听器的波达方向信息对未知目标进行融合定位。在已有的基于位置误差加权方法的基础上,利用几何二次约束减小波达方位角量测误差,并结合泰勒级数展开,将一阶权值推导至高阶,解决在低信噪比情况下定位精度差的问题。仿真结果表明:相对于传统的基于方差倒数的自适应加权算法,该方法在定位精度上有很大提高,尤其在低信噪比的情况下效果显著。

Different lymph node staging systems for predicting the prognosis of colorectal neuroendocrine neoplasms

BACKGROUND Colorectal neuroendocrine neoplasms(NENs)are a rare malignancy that primarily arises from the diffuse distribution of neuroendocrine cells in the colon and rectum.Previous studies have pointed out that the status of lymph node may be used to predict the prognosis.AIM To investigate the predictive values of lymph node ratio(LNR),positive lymph node(PLN),and log odds of PLNs(LODDS)staging systems on the prognosis of colorectal NENs treated surgically,and compare their predictive values.METHODS This cohort study included 895 patients with colorectal NENs treated surgically from the Surveillance,Epidemiology,and End Results database.The endpoint was mortality of patients with colorectal NENs treated surgically.X-tile software was utilized to identify most suitable thresholds for categorizing the LNR,PLN,and LODDS.Participants were selected in a random manner to form training and testing sets.The prognosis of surgically treating colorectal NENs was examined using multivariate cox analysis to assess the associations of LNR,PLN,and LODDS with the prognosis of colorectal NENs.C-index was used for assessing the predictive effectiveness.We conducted a subgroup analysis to explore the different lymph node staging systems’predictive values.RESULTS After adjusting all confounding factors,PLN,LNR and LODDS staging systems were linked with mortality in patients with colorectal NENs treated surgically(P<0.05).We found that LODDS staging had a higher prognostic value for patients with colorectal NENs treated surgically than PLN and LNR staging systems.Similar results were obtained in the different G staging subgroup analyses.Furthermore,the area under the receiver operating characteristic curve values for LODDS staging system remained consistently higher than those of PLN or LNR,even at the 1-,2-,3-,4-,5-and 6-year follow-up periods.CONCLUSION LNR,PLN,and LODDS were found to significantly predict the prognosis of patients with colorectal NENs treated surgically.

北斗观测数据质量及动态PPP性能分析

为分析北斗卫星导航系统(BeiDou Navigation Satellite System,BDS)在全球范围内的数据质量、动态精密单点定位(precise point positioning,PPP)性能及不同区域内的性能差异,选取三个不同区域内共9个多GNSS实验(Multi-GNSS Experiment,MGEX)连续跟踪站的观测数据,以GPS为参考,从卫星可见性、伪距多路径效应、数据完整率、信噪比(signal-to-noise ratio,SNR)及PPP定位精度五个方面对BDS的数据测质量以及定位精度进行分析.结果表明:BDS的卫星可见性具有区域差异,多路径效应及SNR并没有呈现出区域特征,其中北斗三号(BeiDou-3Navigation Satellite System,BDS-3)的数据质量优于北斗二号(BeiDou-2 Navigation Satellite System,BDS-2)的,且BDS不同频点的数据质量也有明显差异,B1I频点数据质量较差. BDS的动态定位精度略弱于GPS,多系统对提高定位精度具有显著的效果.

晚期卵巢癌患者进行满意肿瘤细胞减灭术后盆腹腔淋巴结转移与患者预后分析

目的本研究旨在对晚期卵巢癌患者进行满意肿瘤细胞减灭术后对淋巴结(LN)转移与患者预后进行分析。方法回顾性分析了120例行满意肿瘤细胞减灭术的晚期卵巢癌患者,通过对比分析术后患者的淋巴结状态、转移性淋巴结数量(MLN)、淋巴结转移率(LNR)和阳性淋巴结对数比(LODDS),使用Kaplan-Meier单变量分析和多变量Cox回归分析患者总体生存率,预测术后独立预后因素。根据受试者工作特征(ROC)曲线,比较不同淋巴结指标对晚期卵巢癌患术后生存的预测能力。结果120例晚期患者中淋巴结阴性有71例(59.20%),淋巴结阳性有49例(40.80%),多变量分析结果显示,阳性LN状态、MLN、LNR和LODDS是影响总生存期(OS)独立危险因素。与淋巴结状态、转移性淋巴结数量相比,在预测1年、3年和5年OS时,AUC最高的变量是LODDS(P<0.05)。结论本研究表明阳性LN状态、MLN、LNR和LODDS是预测卵巢癌患者OS的指标。其中,LODDS是预测卵巢癌患者行满意肿瘤细胞减灭术后死亡率的最佳预后预测因子。

提高医用乳胶球囊球形周正率的研究

研究医用乳胶球囊的制备工艺与性能,以期从工艺上解决球囊球偏的问题。结果表明,采用预硫化程度在三末~四初的预硫化天然胶乳,使用酒精陶土凝固剂,并采取合理自动浸渍工艺,在65℃下沥滤6 min,在100℃下带模干燥硫化30 min,制备的乳胶球囊的球形周正率大,物理性能和外观质量好,可满足国内市场需求。

不同坡位轻木人工林土壤养分含量及其化学计量特征

碳(C)、氮(N)和磷(P)通常用于评估土壤质量。为了解云南西双版纳地区不同坡位轻木人工林生长土壤C、N和P含量及其化学计量特征差异,本研究通过野外调查采样与室内分析相结合的方法,以2年生轻木人工林为研究对象,分析比较上坡位和下坡位轻木人工林中土壤C、N和P的化学计量特征及其对轻木生长的影响。测定指标包括土壤有机碳(SOC)、总氮(TN)、总磷(TP)、碱解氮(AN)和有效磷(AP)含量,并评估两个坡位中SOC/TN、SOC/TP、TN/TP和AN/AP值的差异。结果表明:①下坡位轻木树高和胸径较上坡位分别显著增加23.39%和49.43%。②随着土层深度的增加,土壤SOC、TN、TP、AN和AP含量总体呈降低趋势;在3个不同深度的土层中AP含量均表现为下坡位显著高于上坡位,在20~40 cm土层中AN含量也表现出下坡位显著高于上坡位。③40~60 cm土层土壤各养分含量显著低于0~20 cm土层(上坡位TP除外),在0~60 cm 3个不同深度的土层中,AN/AP值均表现为上坡位显著高于下坡位;20~40 cm和40~60 cm土层中,SOC/TP值均表现为下坡位显著高于上坡位。④相关分析和主成分分析结果表明,在上坡位中,主要由SOC/TP、AN/AP和SOC/TN值反映土壤肥力情况;在下坡位中,主要由AP、AN和SOC含量反映土壤养分情况。综上,下坡位轻木的生长状况显著优于上坡位,土壤SOC、AP和AN含量对轻木的生长起关键性作用,也反映了TP、TN与AP、AN的转化情况;AN/AP值反映土壤中养分的可利用效率,对轻木的生长有直接相关作用,可作为当地评估林地养分是否缺失的信号。