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。

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。

老年患者麻醉手术中压力性损伤发生情况调查及其预测模型的建立

目的调查老年患者麻醉手术中压力性损伤的发生情况,建立预测风险的列线图模型并进行内部验证。方法回顾性分析2018-02至2020-08在南充市中心医院进行麻醉手术的老年患者327例。收集麻醉手术中可能发生压力性损伤的因素,根据有无压力性损伤分为两组,比较其差异,并采用多因素Logistic回归分析压力性损伤的影响因素,并建立列线图预测模型进行内部验证。结果327例都完成了皮肤情况的观察,观察期间共41例(12.53%)出现压力性损伤。通过LASSO回归模型筛选出9个潜在的影响因素,并行多因素Logisitc回归分析,结果显示,年龄、BMI、吸烟史、手术体位、术中变换体位、手术时间、术中低温、白蛋白水平是老年患者麻醉手术中发生压力性损伤的独立性影响因素(P<0.05)。ROC曲线显示模型预测老年患者麻醉手术中发生压力性损伤的AUC为0.926(95%CI:0.888~0.965);校准曲线和H-L拟合优度检验结果显示,该列线图模型预测的概率与实际概率差异无统计学意义(P>0.05)。结论老年患者麻醉手术中压力性损伤发生率较高,主要受年龄、BMI、吸烟史等因素影响,根据上述因素建立的列线图模型预测麻醉手术中压力性损伤具有较高的准确度与区分度。

重型颅脑损伤患者胃肠功能衰竭风险预测模型的建立

目的建立重型颅脑损伤(sTBI)患者胃肠功能衰竭风险预测模型,并进行验证。方法选择2019年1月至2023年3月达州市中西医结合医院神经外科接诊的147例sTBI患者资料进行分析。收集可能影响sTBI患者胃肠功能衰竭的相关因素,根据急性胃肠道损伤(AGI)分级将患者分为胃肠功能衰竭组与非胃肠功能衰竭组,以LASSO筛选出潜在影响因素后行多因素Logistic回归分析,根据多因素分析结果建立列线图模型并进行验证。结果本研究模型组102例sTBI患者中共有33例(32.35%)出现胃肠功能衰竭,多因素Logistic回归分析结果显示:机械通气情况、休克、通便措施、肺部感染情况、血钠、人肠脂肪酸结合蛋白(iFABP)、D-乳酸及二胺氧化酶(DAO)为sTBI患者胃肠功能衰竭的独立性影响因素(P<0.05)。ROC分析显示模型组曲线下面积(AUC)为0.942,95%CI为0.896~0.988;验证组AUC为0.908,95%CI为0.849~0.966。校准曲线结果显示,预测曲线与标准曲线基本拟合。决策曲线分析结果显示,当列线图模型预测sTBI患者胃肠功能衰竭风险的概率阈值为0.10~0.90时,患者的净收益率大于0。结论sTBI患者胃肠功能衰竭主要受机械通气情况、休克、通便措施等相关因素的影响,本研究基于上述因素建立的列线图预测模型用于预测sTBI患者胃肠功能衰竭具有较高的准确度与区分度。

一测多评法测定大黄碳酸氢钠片中5种游离蒽醌类成分的含量

目的建立一测多评法(QAMS)测定大黄碳酸氢钠片中5种游离蒽醌类成分的含量。方法采用高效液相色谱法,以大黄酚为内参物,确立芦荟大黄素、大黄酸、大黄素和大黄素甲醚与大黄酚的相对校正因子,并与外标法测定结果进行比较,以验证一测多评法在测定该成分的合理性和可行性。结果8批不同生产企业的样品,一测多评法计算值与外标法实测值无明显差异,相对平均偏差均小于1.0%。结论本方法准确可靠,可用于大黄碳酸氢钠片中5种游离蒽醌类成分的含量测定。

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。

一测多评法测定法制半夏曲中11种成分含量及其GRA、EW-TOPSIS质量评价

目的采用一测多评(QAMS)法同时测定法制半夏曲中肌苷、鸟苷、腺苷等11种成分含量,并建立其灰色关联度分析(GRA)联合熵权逼近理想解排序分析法(EW-TOPSIS)综合质量评价方法。方法采用Shimadzu C 18色谱柱;乙腈-0.5%醋酸为流动相,梯度洗脱,流速1.0 mL·min-1;检测波长254和290 nm。以对甲氧基肉桂酸乙酯为内参比物质,计算其他10个成分的相对校正因子(RCF),测定各成分含量。采用GRA联合EW-TOPSIS模型对法制半夏曲进行综合质量评价。结果法制半夏曲中11种成分在一定浓度范围内线性关系良好,相关系数均>0.999;平均加样回收率96.94%~100.12%(RSD<2.0%,n=9);QAMS与外标法(ESM)实测值无明显差异。GRA模型相对关联度0.2903~0.6187,EW-TOPSIS模型相对接近度0.2114~0.6343;GRA和EW-TOPSIS模型综合评价结果基本一致。结论QAMS法便捷、准确,可用于法制半夏曲多指标成分定量控制,GRA联合EW-TOPSIS模型可用于法制半夏曲综合质量评价。

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。

多因素协同作用下的页岩气井下管道腐蚀分析

国内西南地区某页岩气井下管道出现了不同程度的腐蚀,存在较大的安全隐患。为明确腐蚀类型和机理,开展了井下管道腐蚀分析。研究方法主要包括宏观观察、微观观察和成分分析、流体力学仿真。结果表明:冲刷-CO_(2)-SRB(硫酸盐还原菌)多因素协同作用下的腐蚀是页岩气井下管道的主要腐蚀类型。运行初期SRB的生长与富集造成了局部腐蚀,加入杀菌剂后SRB腐蚀停止,CO_(2)腐蚀在已经形成的局部腐蚀位置继续发展,液带砂和气带砂等流体冲刷作用促进了相关腐蚀的发生、发展。

塔北地区多期走滑断裂地球物理响应特征及精细识别

通过对野外地质露头考察、无人机扫描、探地雷达探测、岩心观察、成像测井资料综合分析,建立塔北地区走滑断裂地质模式。根据塔北地区不同地层特点,分析多期走滑断裂与不同时期地层组合关系。针对不同的地层岩相背景下的走滑断裂特征,分析对应的地球物理响应特征,为小断距、小位移的走滑断裂识别提供依据。结果表明:加里东中晚期,在挤压应力作用下区域走滑断裂形成,发育X型共轭断裂和单剪切断裂,其中NNE向走滑断裂为左旋,NNW向走滑断裂为右旋;由于挤压应力差异分布,沿主干断裂方向寒武系膏盐岩滑脱面形成线性压扭隆起和平移错断的特点,结合膏盐岩层强地震反射特征,主干断裂可识别性强;中上奥陶统走滑断裂走向与古地貌趋势具有一致性;由于北部表层岩溶暴露期长,研究区形成大量的残丘、暗河、古水系,破坏了浅层断裂特征,而南部斜坡区暴露时间短,岩溶缝洞体主要沿断裂发育,断控岩溶缝洞体与基岩波阻抗存在较大差异,增强了断裂的可识别特征;海西期NNW方向、喜山期NNE方向发育单剪切走滑断裂,主要沿加里东中期断裂继承性发育,碎屑岩地层不整合面断距特征明显,平面上表现为雁列特征,剖面可见负花状构造。

基于N-K模型的石化储罐事故风险耦合度分析

为预防石化储罐事故,通过收集212份石化储罐事故报告,将事故风险因素归纳为人为、设备、环境、管理4个类别,利用N-K模型分析事故风险因素之间的耦合作用,并运用N-K模型计算各种耦合模式下的风险耦合度,得出了石化储罐事故风险因素的耦合关系及耦合作用规律。结果表明,随着参与耦合的因素增多,风险耦合值总体呈现上升趋势;人为因素与其它因素耦合更容易导致事故;石化储罐区事故各风险因素之间的耦合作用程度相比其它行业更高。研究结果可为石化企业储罐事故管控提供依据和参考。

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。