Multi-factor analysis of initial poor graft function after orthotopic liver transplantation

BACKGROUND: In the early period of orthotopic liver transplantation (OLT), initial poor graft function (IPGF) is one of the complications which leads to primary graft non-function (PGNF) in serious cases. This study set out to establish the clinical risk factors resulting in IPGF after OLT. METHODS: Eighty cases of OLT were analyzed. The IPGF group consisted of patients with alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) above 1500 IU/L within 72 hours after OLT, while those in the non-IPGF group had values below 1500 IU/L. Recipient-associated factors before OLT analyzed were age, sex, primary liver disease and Child-Pugh classification; factors analyzed within the peri-operative period were non-heart beating time (NHBT), cold ischemia time (CIT), rewarming ischemic time (RWIT), liver biopsy at the end of cold ischemia; and factors analyzed within 72 hours after OLT were ALT and/or AST values. A logistic regression model was applied to filter the possible factors resulting in IPGF. RESULTS: Donor NHBT, CIT and RWIT were significantly longer in the IPGF group than in the non-IPGF group; in the logistic regression model, NHBT was the risk factor leading to IPGF (P<0.05), while CIT and RWIT were possible risk factors. In one case in the IPGF group, PGNF appeared with moderate hepatic steatosis. CONCLUSIONS: Longer NHBT is an important risk factor leading to IPGF, while serious steatosis in the donor liver, CIT and RWIT are potential risk factors.

Multi-factor sensitivity analysis of shallow unsaturated clay slope stability

An unsaturated clay slope, with various sloping angles and a thickness of 14 m, consists of backfill, slope soil and residual soil. Slide interfaces were determined by geophysical approaches and the original slope was reconstructed. Sub-slope masses were classified based on the varieties of sloping angle. A force recursive principle was proposed to calculate the stability coefficient of the sub-slope masses. The influencing factors such as sloping angle, water content, hydrostatic pressure, seismic force as well as train load were analyzed. The range and correlation of the above-mentioned factors were discussed and coupled wave equations were established to reflect the relationships between unit weight, cohesion, internal frictional angle, and water content, as well as between internal frictional angle and cohesion. The sensitivity analysis of slope stability was carried out and susceptive factors were determined when the factors were taken as independent and dependent variables respectively. The results show that sloping angle, water content and earthquake are the principal susceptive factors influencing slope stability. The impact of hydrostatic pressure on slope stability is similar to the seismic force in quantity. Train load plays a small role in slope stability and its influencing only reaches the roadbed and its neighboring slope segment. If the factors are taken as independent variables, the influencing extent of water content and cohesion on slope stability can be weakened and train load can be magnified.

Multi-factor Analysis Model for Improving Profit Management Using Excel in Shellfish Farming Projects

By using a farm's data in Yantai City and the theory of Cost-Volume-Profit analysis and the financial management methods,this paper construct a multi-factor analysis model for improving profit management using Excel 2007 in Shellfish farming projects and describes the procedures to construct a multi-factor analysis model.The model can quickly calculate the profit,improve the level of profit management,find out the breakeven point and enhance the decision-making efficiency of businesses etc.It is also a thought of the application to offer suggestions for government decisions and economic decisions for corporations as a simple analysis tool.While effort has been exerted to construct a four-variable model,some equally important variables may not be discussed sufficiently due to limitation of the paper's space and the authors'knowledge.All variables can be listed in EXCEL 2007 and can be associated in a logical way to manage the profit of shellfish farming projects more efficiently and more practically.

ANALYSIS OF PSYCHOLOGIC HEALTH STATE AND INFLUENCING FACTORS IN COLLEGE AND SECONDARY SCHOOL STUDENTS IN SHAANXI PROVINCE

Objective The psychologic health level of college and secondaryschool students and the relevant factors were investigated to scientific basis and guidance for school mental health work.Methods Standard 1251 cases were drawn from 1‰ of students in colleges and middle schools of Shaanxi province.Taking 14 psychic health level indexes in SCL 90 as dependent variable and 109 indexes of psychic health back ground as in dependent variable, multi factor analyses have been made.Results 22.6% of students had relatively serious psychological problems.The score of SCL 90 in females was a little bit higher than that in males.The scores of students at both universities and senior middle schools were higher than that in junior middle schools students.The score of SCL 90 of students who came from the countryside was higher than that of city students.The score of the whole students was higher than that of the normal.The students with psychic problems showed obsession,interpersonal sensitivity,depression,anxiety,paranoia and hostility.Factor analysis showed that influencing factors included history of positive individual risking behavior,physical conditions,grade,address,family influences,menses and sexual prombles,bad relation with others,poor self assessment.Conclusion The psychologic health level of the students investigated is lower than that of the whole society.The factors,which hamper psychic health of students, are biological,psychological and social in nature.

Analysis on the Seismic Response of Soil Slopes Based on the Multi-point Input Method

In general, the seismic response analysis in earthquake engineering assumes that the vibration parameters of the target and the contact surface of the external media are identical,i. e., single point input. However, earthquake energy has an attenuation phenomenon in wave propagation,so a wide range of soil slopes and the external medium contact surface of different input points on motion are not identical. If we consider single point input only, it may not correspond with reality, so it is necessary to carry out research on multi-point input methods. Based on the 2-D slope model,single-point input and multi-point input are performed respectively to analyze and compare their similarities and differences in the perspectives of the characteristics of seismic response of soil layer and plastic zone distribution to provide a reference for the seismic design of slopes. The results show that in the perspective of soil seismic response analysis,the peak acceleration output and peak velocity output under multi-point input are greater than the peak values under single point input at the same monitoring point,the peak appearing time is also earlier than that of the single point input; in terms of the plastic zone distribution,the multi-point effect is manifested as the presence of more obvious tensile shear failures; in the perspective of safety coefficient,the safety coefficient under each multi-point input is smaller than that of single point input,a difference of about 7 % or so. In summary,multi-point input is more reasonable and practical than single point input,so multi-point input should be considered in seismic design.

Logistic Regression Analysis of Influencing Factors on Serum ALT and HCV RNA Changes in Patients with Chronic Hepatitis C

Objective This study was undertaken to investigate the influencing factors on serum ALT level and hepatitis C virus(HCV)RNA titer in chronic hepatitis C(CHC)patients.Methods All patients enrolled into this study were anti-HCV positive.Retrospective tracing method was applied to detect serum ALT level and HCV RNA titer and to collect general information of the patients such as genders,age groups,interferon medication history,infection pathways,height and weight.Then the multi-factor analysis was adopted with the application of binominal logistic regression mode.Results The abnormal rate of ALT level was positively correlated to HCV RNA and gender while negatively correlated to interferon medication history and age group,with Wald value of the 4 factors as 39.604,11.823,18.991 and 7.389,respectively.The positive rate of HCV RNA was negatively correlated to interferon medication history and gender while positively correlated to ALT level,with corresponding Wald value of the 3 factors as81.394,7.618 and 27.562,respectively.Conclusions The normal ALT level in HCV infected patients was associated with viral load,age,gender and interferon medication history,while the normal rate of HCV RNA titer was closely associated with gender,interferon medication history and ALT level.

基于LMDI-Attribution的山西省碳排放强度分析

运用LMDI-Attribution方法对山西省2005~2014年间碳排放强度进行了分解及归因分析,并将传统的LMDI模型扩展到产业部门和居民生活两部分,量化五大行业对影响效应变化的贡献率。结果表明,山西省碳排放强度呈下降趋势,2014年万元生产值碳排放强度比2005年减少了2.603 29 t。其中,影响其变化的3个主要因素是经济规模、能源强度和居民能源消费结构;农业、工业、建筑业、交通业、商业5个行业对能源强度效应和产业结构效应均有抑制碳排放强度增长作用;其中,工业是能源结构、能源强度和产业结构3个效应变化的最主要因素,而低耗能的农业、交通业、商业的影响力微弱。总体而言,工业是山西省未来减排最需要关注的部门,优化产业结构和能源结构,大力发展清洁能源是山西省绿色低碳发展的最佳途径。

Multi-attributed decision making for mining methods based on grey system and interval numbers

In the case of unknown weights, theories of multi-attributed decision making based on interval numbers and grey related analysis were used to optimize mining methods. As the representative of independence for the indicator, the smaller the correlation of indicators is, the greater the weight is. Hence, the weights of interval numbers of indicators were determined by using correlation coefficient. Relative closeness based on positive and negative ideal methods was calculated by introducing distance between interval numbers, which made decision making more rational and comprehensive. A new method of ranking interval numbers based on normal distribution was proposed for the optimization of mining methods, whose basic properties were discussed. Finally, the feasibility and effectiveness of this method were verified by theories and practice.

Reservoir prediction using multi-wave seismic attributes

The main problems in seismic attribute technology are the redundancy of data and the uncertainty of attributes,and these problems become much more serious in multi-wave seismic exploration.Data redundancy will increase the burden on interpreters,occupy large computer memory,take much more computing time,conceal the effective information,and especially cause the "curse of dimension".Uncertainty of attributes will reduce the accuracy of rebuilding the relationship between attributes and geological significance.In order to solve these problems,we study methods of principal component analysis (PCA),independent component analysis (ICA) for attribute optimization and support vector machine (SVM) for reservoir prediction.We propose a flow chart of multi-wave seismic attribute process and further apply it to multi-wave seismic reservoir prediction.The processing results of real seismic data demonstrate that reservoir prediction based on combination of PP-and PS-wave attributes,compared with that based on traditional PP-wave attributes,can improve the prediction accuracy.

Effect of Multi-parameter Environmental Factors on Cucumber Leaf Surface Wetness

In this study, artificial leaf resistance was used to simulate leaf wetness. Specific to the solar greenhouse environment in Tianjin, microclimate monitoring equipment was installed for the collection of temperature group and humidity group data, as well as solar radiation and leaf wetness in the greenhouse. In order to reduce the complexity of multivariate factor prediction and ensure the richness of selected data types, correlation analysis was made to the 2 groups of data, screening 5 000 groups of data, including the humidity group data RH, RH_(20), RH_(40), temperature group data T, T_(20), T_(40), and solar radiation W. The data were then analyzed by principal component analysis, screening out 4 groups of principal components to show the leaf wetness index.

水资源-能源-粮食-生态系统耦合协调及驱动力分析

为加深对我国水资源、能源、粮食、生态系统协同演变趋势的认识,构建水资源-能源-粮食-生态多维系统指标体系,运用耦合协调度模型对我国2005—2020年水资源-能源-粮食-生态系统耦合协调度进行评价,并采用多因素归因分析法进行驱动力分析。结果表明:我国水资源-能源-粮食-生态系统耦合协调度从2005年的0.55增长到2020年的0.84,各地区耦合协调度从勉强协调发展水平过渡到中级协调发展水平,各子系统对耦合协调度上升的驱动分别经历了由粮食子系统到生态子系统再到水资源子系统主导的过程;能源子系统的贡献率虽然比较小,但是未来可能是各地区提升水资源-能源-粮食-生态系统多维系统协调发展水平的突破口。

考虑多影响因素的渔船单船捕捞能力评估方法

针对以往海洋机动渔船捕捞能力评估研究中考虑影响因素较少,对各影响因素的主观权重值和客观权重值综合分析不足,不能给出渔船单船捕捞能力量化值等问题,该研究提出了考虑多影响因素的渔船单船捕捞能力评估模型。首先,考虑多种影响渔船捕捞能力的因素,建立单船捕捞能力评估指标体系,将其分为可量化指标和不可量化指标,并初步制定了不可量化指标评估标准。其次,利用专家、渔民调查问卷中的数据,运用层次分析法计算各指标主观权重值,结果表明各指标权重依次为:捕捞装备(0.108)、功率(0.094)、拖网(0.074)、作业时长(0.071)、总吨(0.049)、探鱼仪器(0.047)、刺网(0.040)、船长(0.032)、张网(0.028)、围网(0.024)、钓业(0.021)、作业环境(0.019)、钢质材质(0.019)、罩网(0.017)、玻璃钢材质(0.016)、船龄(0.013)、木制材质(0.012);渔具相关指标权重依次为:网具主尺寸(0.402)、网具结构(0.149)、装配技术(0.093)、制造材料(0.051)。最后,为兼顾主客观权重优点,基于加法合成法、博弈论法、最小鉴别信息法对各指标权重值进行组合计算,以获得目标权重值,并根据某省渔船数据对建立的模型进行验证分析,通过Spearman等级相关系数法计算捕捞能力评估值与实际渔获量之间的等级相关系数,结果表明基于博弈论法得到的结果相关性最高,相关系数为0.937,证实了组合权重值和评估模型的科学性和合理性。研究结果可为渔业管理部门制定科学合理的渔业资源调控政策提供依据。

基于多分量LFM信号时频分析的水声多普勒和时延估计研究

在水声多普勒因子和时延估计研究实用化的进程中,利用多分量线性调频(LFM)信号实现估计的算法研究越来越普遍。针对多分量LFM信号时频域存有交叉项时各分量参数估计不准确的问题,提出基于非完全残差与脊线段匹配的自适应模态分解方法。该方法采用非完全残差函数保留了交叉点处的部分时频信息,利用脊线段匹配方法提供更精确的预设时频脊线,改进了各分量LFM信号调频斜率和起始频率的估计精度。联合两个估计量进一步给出了多普勒因子和时延估计的算法。仿真结果表示,较现有模态分解算法,所提改进方法有效解决了估计分量过程中交叉区间断裂带来的估计误差;水声多径的条件下,该方法的多普勒因子和时延估计精度优于对比的现有方法。

脑梗死患者脑脊液溶血磷脂酸水平与神经功能缺损状态的相关性分析

目的探讨与分析脑梗死(cerebral infarction,CI)患者脑脊液溶血磷脂酸(plasma lysophosphatidic acid,LPA)水平与神经功能缺损状态的相关性分析。方法选择2020年3月—2022年11月在北京市昌平区中西医结合医院诊治的67例脑梗死患者作为研究对象,所有患者在入院时进行神经功能缺损状态美国国立卫生研究院卒中量表(National Institute of Health Stroke Scale,NIHSS)评分,检测脑脊液溶血磷脂酸水平并进行相关性分析。结果在67例患者中,平均神经功能缺损状态NIHSS评分为(18.32±2.15)分,其中>21分17例(重度组)。重度组性别、身体质量指数、受教育程度、合并疾病等与非重度组对比,差异无统计学意义(P>0.05),重度组与非重度组的年龄、发病到入院时间等对比,差异有统计学意义(P<0.05)。重度组与非重度组的血糖、同型半胱氨酸、总胆固醇、甘油三酯含量对比,差异无统计学意义(P>0.05),重度组的低密度脂蛋白胆固醇含量高于非重度组,差异有统计学意义(P<0.05)。重度组的脑脊液溶血磷脂酸水平显著高于非重度组,差异有统计学意义(P<0.05)。Pearson分析显示NIHSS评分与年龄、发病到入院时间、脑脊液溶血磷脂酸水平都存在正相关性(P<0.05)。logistic回归分析显示年龄、发病到入院时间、脑脊液溶血磷脂酸水平为影响脑梗死患者NIHSS评分的重要因素(P<0.05)。结论脑梗死患者的神经功能缺损状态比较严重,神经功能缺损状态越差的脑梗死患者,脑脊液溶血磷脂酸水平越高,脑梗死患者脑脊液溶血磷脂酸水平与神经功能缺损状态存在相关性。

超音速火焰喷涂铁基非晶纳米晶涂层的工艺参数与性能试验

为了进一步深入研究铁基非晶涂层的制备和性能,利用人工神经网络和多因素多水平设计对超音速火焰喷涂技术制备的铁基非晶纳米晶涂层的工艺参数和性能进行了优化,以期对铁基非晶涂层的实际应用提供参考.多因素多水平试验通过设计分析方法和设计实验参数,建立神经网络模型,研究了煤油量、氧气量、送粉率和喷涂距离四项工艺参数对涂层孔隙率、硬度、结合强度和沉积效率的影响规律.采用扫描电镜、透射电镜等手段表征了粉末及涂层的显微结构和内部微观组织形貌;采用X射线衍射仪、同步热分析仪等设备对粉末和涂层成分、相组成和非晶程度进行了观察分析.验证了工艺参数优化过程的计算机模拟结果,确定了最佳喷涂工艺参数范围,进一步提升了涂层的性能.讨论了喷涂过程中孔隙形成的微观过程和非晶纳米晶对涂层性能的影响机理.研究表明各工艺参数对涂层性能是多因素互相影响的,理论上最佳喷涂工艺参数为煤油量23 L·h^(-1)、氧气量51 L·h^(-1)、送粉率72 g·min^(-1)、喷涂距离280 mm,制备出的铁基非晶涂层厚度约为270μm、孔隙率约为1.3%、结合强度约为84 MPa、硬度约为1110 HV_(0.3).涂层非晶程度在80%左右,纳米晶尺寸为3~5 nm,涂层在600℃以下不会发生晶化过程.

基于Multi-Agent的多属性拍卖评标机制的仿真研究

针对当前分组多属性评标机制,在评标专家有限理性的前提下,存在着评标专家抬分和压分越来越严重、对立情绪累积现象明显和组间评标结果差异越来越大的问题。提出加入综合专家组或增设一对反映标的负相关新指标的策略改进当前评标机制,描述了改进评标机制的原型系统,构建了基于Multi-Agent的分组评标行为仿真构架,在定义各Agent的属性、决策规则和交互协作方式基础上,给出了仿真的具体步骤,定义了相关行为参数,利用Matlab GUI平台实现评标行为仿真分析系统,设定相关参数进行三种机制下的评标模拟与比较,仿真结果表明:改进后的分组评标机制有效地控制了评标结果差异增大,相对合理地调节了评标专家评分标准,提高了评标公平性,体现了改进机制的有效性,为评标决策提供依据。

基于分布式多关联属性的高维数据差分隐私保护方法

针对高维数据发布的过程中存在由多关联属性引发的隐私信息泄露风险问题,在分布式环境下提出一种满足差分隐私保护的多关联属性高维数据发布方法(HDMPDP)。根据数据维度,提出一种基于分布式划分的粗糙集高效降维方法,完成对高维复杂数据特征属性的划分,降低数据维度的同时提高处理效率;设计属性分类准则,利用属性信息熵改进关联分析方法;对得到的属性分别进行加噪,优化噪声添加的方式,减轻关联属性带来的隐私问题。在Spark分布式框架下实现隐私保护数据发布,通过高维数据实验验证了该方法的有效性和隐私保护的安全性。

基于时空认知膨胀卷积网络与多源影响因素的PM_(2.5)细粒度预测模型

为实现精确化、细粒度的PM_(2.5)浓度预测,提出了基于时空认知膨胀卷积网络(spatial-temporal cognitive dilated convolution network,ST-C-DCN)的PM_(2.5)浓度预测模型ST-C-DCN。该模型将时空因素、气象因素运用于PM_(2.5)浓度预测,基于因果卷积网络提取时空特征,并采用时空注意力机制优化了时空特征的提取。基于海口市空气污染数据的实验测试表明:对于单个监测站,基线模型相比,ST-C-DCN的均方根误差(root mean square error,RMSE)平均下降24.7%,平均绝对误差(mean absolute error,MAE)平均下降9.93%,拟合优度(R-squared,R^(2))平均上升3.35%。对于全部监测站点的预测,ST-C-DCN在win-tie-loss(包括MSE、RMSE、MAE、R^(2))实验中,均获得了最多的获胜次数,分别为68,68、63和64。通过不同数据抽样条件下的Friedman检验,证明了ST-C-DCN对比基准有显著的性能提升。ST-C-DCN为细粒度PM_(2.5)预测提供了一个具有潜力的方向。

儿童免疫性血小板减少症复发危险因素的调查及其预测模型的构建

目的调查儿童免疫性血小板减少症(ITP)复发情况,并建立其预测模型。方法选择2018年1月至2022年4月苏州市吴江区儿童医院(苏州大学附属儿童医院吴江院区)及苏州大学附属儿童医院接诊的ITP患儿288例进行研究。收集可能影响儿童ITP复发相关因素,将模型组患儿根据有无复发分为2组,比较2组各指标,并以LASSO回归筛选出潜在影响因素后以Logstic回归分析筛选出儿童ITP患者复发的独立性影响因素,采用R语言构建列线图模型并进行验证。结果模型组201例患者中共有37例(18.47%)出现复发,复发组与未复发组患者年龄、血型、治疗前病程、前驱感染、出血情况、初始治疗方案、抗核抗体、初诊血小板计数、初诊平均血小板体积、初诊血小板分布宽度、初诊外周血淋巴细胞计数、治疗后血小板计数升至有效时间比较差异均具有统计学意义(P<0.05)。LASSO回归基础上行多因素Logistic回归分析:血型、治疗前病程、前驱感染、初始治疗方案、初诊外周血淋巴细胞计数、治疗后血小板计数升至有效时间为儿童咳嗽变异性哮喘转为典型哮喘的独立性影响因素。根据多因素分析结果,以R语言建立儿童ITP复发预测列线图模型。接受者操作特征曲线(ROC)分析结果显示,模型组列线图模型预测儿童ITP复发的AUC为0.867[95%CI(0.796,0.938)]灵敏度为84.2%,特异度为73.1%;验证组曲线下面积(AUC)为0.838[95%CI(0.765,0.911)]灵敏度为82.3%,特异度为78.4%。采用Bootstrap法重复抽样1000次,并以验证组进行验证,校准曲线结果显示:模型组与验证组预测曲线与标准曲线基本拟合,提示模型预测准确度较高。模型组决策曲线分析结果显示:当该列线图模型预测儿童ITP复发的概率阈值为0.15~0.75时,患者的净受益率大于0。结论儿童ITP复发主要受患者年龄、血型、治疗前病程等因素的影响,根据上述因素建立的列线图模型用于育儿儿童ITP复发具有较高的准确度与区分度。