Molecular weight determination of a newly synthesized guanidinylated disulfide-containing poly(amido amine) by gel permeation chromatography

A cationic gene delivery vector, guanidinylated disulfide-containing poly(amido amine)(CARCBA), was synthesized by Michael addition reaction between N,N′-cystaminebisacrylamide(CBA) and guanidine hydrochloride(CAR). Gel permeation chromatography(GPC) was used to evaluate the molecular weight of synthesized CAR-CBA. Polyethyleneimine(PEI) with molecular weight of 25 kDa was adopted as a reference, and polyethylene glycols(PEG) with different molecular weights were used to establish a standard curve for determining the molecular weight of CAR-CBA. The effects of two critical factors, namely columns and eluents,on the molecular weight measurement of CAR-CBA were investigated to optimize the GPC quantitative method. The results showed that Ultrahydrogel columns(120, 250) and HAc–NaAc(0.5 M, pH 4.5) buffer solution were the optimal column and GPC eluent, respectively.The molecular weight of the synthesized CAR-CBA was analyzed by the optimized GPC method and determined to be 24.66 kDa.

Sociodemographic determinants associated with breastfeeding in term infants with low birth weight in Latin American countries

BACKGROUND A progressive decrease in exclusive breastfeeding(BF)is observed in Latin America and the Caribbean compared with global results.The possibility of being breastfed and continuing BF for>6 months is lower in low birth weight than in healthy-weight infants.AIM To identify factors associated with BF maintenance and promotion,with particular attention to low-and middle-income countries,by studying geographic,socioeconomic,and individual or neonatal health factors.METHODS A scoping review was conducted in 2018 using the conceptual model of social determinants of health published by the Commission on Equity and Health Inequalities in the United States.The extracted data with common characteristics were synthesized and categorized into two main themes:(1)Sociodemographic factors and proximal determinants involved in the initiation and maintenance of BF in low-birth-weight term infants in Latin America;and(2)individual characteristics related to the self-efficacy capacity for BF maintenance and adherence in low-birth-weight term infants.RESULTS This study identified maternal age,educational level,maternal economic capacity,social stratum,exposure to BF substitutes,access to BF information,and quality of health services as mediators for maintaining BF.CONCLUSION Individual self-efficacy factors that enable BF adherence in at-risk populations should be analyzed for better health outcomes.

Supply Chain Finance Credit Risk Evaluation Method Based on Self-Adaption Weight

Credit risk is the core issue of supply chain finance. In the supply chain, problems happened in different enterprises can influent the whole to different degrees through transferring, thus statuses of all enterprises and their different influences should be considered when evaluating the supply chain’s credit risk. We examine the characters of supply chain network and complex network, use the local growing complex network to simulate the real supply chain, use cluster analysis to classify the company into several levels;Introducing each level’s self-adaption weight formula according to the company’s quantity and degrees of this level and use the weight to improve the credit evaluation method. The research results indicate that complex network can be used to simulate the supply chain. The credit risk evaluation (CRE) of an enterprise level with bigger note degrees has a greater weight in the supply chain system’s CRE, thus has greater effect on the whole chain. Considering different influences of different enterprise levels can improve credit risk evaluation method’s sensitivity.

Self-determinate evaluation method based on condition of weights non-dictatorial rate

The condition of weightes non-dictatorship is extended and a comprehensive evaluae method emboding self-determinate which is combined with competitive view optimization principles is built. The basic process includes simulating the model of economic man＇s self-benefit bahaviors, taking the place of experts to evaluate, bringing in the model of minimizing the sum of included angles to integrate the information of multiple objects and put the objects in order finally. The method has the advangtages of less dependendence on the subjective information, plenty of information, fair process and simple caculating. Finally, an application example is given to illustrate the effectiveness of the proposed method.

Prevalence of term low birth weight andits determinants in Shanghai, China

Objective: To investigate the prevalence of term low birth weight (TLBW) and its risk factors. Methods: A follow-up study with 7, 872 couples was conducted from 1987 to 199o beginning from the time they got marriage licenses in two districts defined in Shanghai. They were interviewed in the third month and again in the fifteenth month and in the fifth to sixth year afterwards individually at home. The total follow up rate reached 98%. Couple’s background characteristics as well as the information on their general health. reproductivc history and contraceptive use etc.. were collected dynamically. All of the single live births with term delivery were Included for data analysis in this paper. Adjusted odd ratios and population attributable risk (PAR%) were computed. Results: The prevalence of TLBW in Shanghai single term live births was 2. 0% (134,/6.573), represents 54. 7% (134/245) of the total low birth weights in our sam pie. Significant social and behaviour risk factors relating with TI-BW were wife’s dissat- isfaction with marriage; low education level of husband; co-residence with parents during pregnancy; heavy housework done by the wife while being pregnant. Significant biomedical risky factors were menarche age greater than 16 years old; maternal age at delivery greater than 29 years old; maternal body mass index less than 19. 8; wife suf- fered from serious disease prior to conceiving; having pregnancy complication; gestational weight gain less than 20 % of pre-pregnancy weight; having abortion, stillbirth and fetal death history. Conclusion: TL.BW constituted over half of all low birth weights in Shanghai. Special attention should be paid to the determinants mentioned above in TLBW intervention program. Improving couples’ economic and living condition and husband ’s education at tainment, and caloric supplementation with women while being pregnant would all be particularly effective in reducing the occurrence of TLBW in Shnaghai.

Rapid satellite-to-site visibility determination based on self-adaptive interpolation technique

Rapid satellite-to-site visibility determination is of great significance to coverage analysis of satellite constellations as well as onboard mission planning of autonomous spacecraft. This paper presents a novel self-adaptive Hermite interpolation technique for rapid satellite-to-site visibility determination. Piecewise cubic curves are utilized to approximate the waveform of the visibility function versus time. The fourth-order derivative is used to control the approximation error and to optimize the time step for interpolation. The rise and set times are analytically obtained from the roots of cubic polynomials. To further increase the computational speed, an interval shrinking strategy is adopted via investigating the geometric relationship between the ground viewing cone and the orbit trajectory. Simulation results show a 98% decrease in computation time over the brute force method. The method is suitable for all orbital types and analytical orbit propagators.

Predictors of Low Birth Weight in Newborn Delivered in Public Hospital of Gurage Zone, Southern Ethiopia: A Case-Control Study

Worldwide, low birth weight is one of the most common causes of neonatal morbidity and mortality. Though factors associated with low birth weight vary from one region to another, in Gurage Zone, there is no sound analytical study done to examine the local determinants of low birth weight. Because of this, the study aimed to elucidate the predictors of low birth weight in public hospital of Gurage zone. Methods: A facility based unmatched case-control study design was employed to detect the existing exposure difference between cases and controls. The study included a total of 270 controls (normal weight) and 134 cases (low birth weight baby). Control and case participants were selected through consecutively. To collect the data, structured interviewer administered questionnaires and anthropometric measurement were used. The data were entered through Epi-data 3.1 computer program and analyzed through Statistical package for Social Sciences version 21 (SPSS v. 21). Univariate, Bivariate and Multivariate analysis were done. Result: Multiple logistic regression model analysis indicated that low birth weight was independently associated with maternal mid upper arm circumference less than 23 cm (AOR 1.79 (95% CI = 1.01 - 3.16)), gestational age less than 37 weeks (AOR 24.94 (95% CI = 12.38 - 50.27)), presence of malaria infection during period of pregnancy (AOR 3.02 (95% CI = 1.39 - 6.51)), presence of preclampsia, multiparity (AOR 2.19 (95% CI = 1.21 - 3.96)) and twining (AOR 5.42 95% CI = 2.01 - 14.59). Conclusion: Gestational age < 37 weeks, twining, malaria infection during pregnancy and maternal undernutrition were a significant predictor of LBW in the region of Gurage zone. Hence, to effectively prevent low birth weight, Gurage zone health departments should work on promotion of maternal nutrition during pregnancy, prevention of malaria during pregnancy.

Kac Determinant Formula for the q-deformed Virasoro Algebra of Hom-type

We investigate the highest weight representations of the q-deformed Virasoro algebra of Hom-type. In order to determine its unitarity and irreducible highest weight representations, we present its Kac determinant formula when q is nonzero and non-root of unity.

Mapping determinants of rural poverty in Guangxi–a less developed region of China

Rapid urbanization in China has led to an increasing imbalance in regional development.The Guangxi Zhuang Autonomous Region,a less developed border region with unique cultural diversity,has a relatively large population(4.52 million people in 2015)under the poverty line,according to the national standard of poverty.China has launched a national campaign to reduce poverty using a wide range of new development policies and large-scale investment.However,there have been few studies on the determinants of poverty at the county level across a province.This paper aims to explore the spatial and social differences related to poverty among 109 counties by considering the spatial heterogeneity of poverty determinants.Spatial statistical models revealed that slope(Slp),GDP per capita(GDPP),the ethnic minority population ratio(EMPR),medical and technical personnel of healthcare institutions(MTP)and illiteracy rate(IR)significantly affect the patterns of the poverty rate,with a high adjusted R2(0.67),while the poverty rate affects GDPP,IR,MTP and EMPR;i.e.,the effects are interactional.Furthermore,the IR is significantly affected by the provision of schools and transportation conditions.Among these determinants,social factors may be key.The spatial patterns of these relationships demonstrate remarkable variation across the province and between minor and major groups.This quantitative evidence is enhanced by indepth interviews with selected groups.These results are expected to be useful for the anti-poverty project in Guangxi.

Method for Automatically Determining the Importance of Criteria in Multicriteria Decision-Making Problems

Multicriteria group decision-making problems （DMP） require criteria weights. Assigning weights of importance of the criteria Face Decision-maker （DM） means, in essence, a priori purpose variant of the winner. There are a number of problematic situations involving a large number of criteria： （1） problems where the evaluation of alternatives represent the degree of satisfaction of basic performance requirements object bidders. Matrix estimates with different low variability and a very large number of requirements （criteria）; （2） the use of cognitive maps for modeling problem situations. If the alternatives are considered not only divisible strategy （options impact on concepts）, matrix estimates accepts small size. If the task is allowed to use an alternative strategy mixtures fraction （e.g., 25% influences on the concept 1, 50% influences on the concept 2, 10% influences on the concept 3, etc.）, the matrix ratings also gaining greater dimension. It is clear that in such cases the appointment criteria weights DMP becomes a problem.

An integrated method for matching forest machinery and a weight-value adjustment

Proper matching of forestry machinery is important when raising mechanization levels for forestry production. In the matching process, forestry machinery needs not only expertise, but also improved methods for solving problems. I propose combination of case-based reasoning （CBR） and rule-based reasoning （RBR） by calculating the similarity of quantitative parameters of various forestry machines in an analytical and hierarchical process. I calculated the similarity of machin-ery used in forest industries to enable better selection and matching of equipment. I propose a weight-value adjusting method based on sums of squares of deviations in which the individual parameter weights were modified in the process of application. During the process of system design, I put forward a design method knowledge base and generated a dynamic web reasoning framework to integrate the processes of forest industry machinery selection and weight-value adjustment. This enables expansion of the scope of the complete system and enhancement of the reasoning efficiency. I demonstrate the validity and practicability of this method using a practical example.

A Cross-Linguistic Comparison of Determiner Arrangement and its Pedagogic Implications

The surface configurations of quantifiers and scope-determiners in Chinese and English NPs show both similarities and differences which may result in acquisition bewilderment for Chinese learners of English. Various English determiners are found to play unequal cognitive roles in terms of their semantic weight. An explanatory method is suggested to address language-specific cognitive features. It may render L2 acquisition a more insightful process and minimize the L1 interference.

山洪灾害危险性评估研究综述

山丘区地形复杂、雨洪资料相对匮乏,非工程措施成为应对山洪灾害的主要途径,山洪灾害危险性评估作为山洪灾害预报预警确定重点靶区、靶点及灾情综合评估的重要依据,已成为山洪灾害防灾减灾非工程措施中的热点与难点问题。从辨析山洪灾害危险性评估的内涵出发,归纳总结了山洪灾害危险性评估方法的研究现状,并根据评估指标体系的差异性将山洪灾害危险性评估方法分为基于特征参数方法和基于情景推演方法两种,其中情景推演方法根据降雨致灾因子的多样性和动态变化性,能够实现山洪灾害危险性动态评估,有助于提高危险性评估精度,是未来的研究趋势。

矿井通风系统综合评价指标体系与方法

对矿井通风系统进行科学合理的综合评价是矿井通风系统优化与调整的重要依据,目前仍未形成公认的综合评价指标体系与方法。针对矿井通风系统综合评价中存在指标体系的确定不够合理、权重维护困难等问题,采用理论分析、文献分析等方法,从矿井通风系统组成要素、性质、能力等3个角度,“通风动力、通风网络、通风设施”“安全可靠性、经济合理性”“保障能力、防灾能力、抗灾能力”等8个维度选取10项评价指标构建矿井通风系统综合评价指标体系。该评价指标体系可以从多角度、多维度全面反映被评价对象的综合情况,抓住主要因素,确保综合评价的全面性和可信度。同时,提出了以等距分级、等比赋权进行排序打分的权重确定方法,即专家排序指数赋权法,以快速确定与维护评价权重,使评价结果具有客观性,又易于操作。

面向电力多模态融合的语义差异性和感知能力差异性分析方法

多模态融合是实现电力系统数字化的重要技术手段,但多模态特征间的差异性限制了融合感知效果。因此,首先对电力多模态数据融合中的语义差异性和感知能力差异性现象进行了深入分析,对差异性产生的特征同化和权重决策问题进行了剖析。然后,针对语义差异性问题,使用角度差对多模态语义差异进行表征,并基于此寻找联合表征空间,实现电力多模态特征同化;其次,针对感知能力差异性问题,使用交叉损失熵对电力多模态感知能力进行表征,并基于此构建权重决策模块,实现多模态特征融合权重计算。最后,以前期所提融合框架为基础,提出了针对多模态差异性问题的高容错性特征融合模型。仿真以输变电线路应急抢修场景为例,基于所提分阶段训练策略进行模型训练,并从融合感知、特征同化以及权重决策机制3个方面验证了所提方法的有效性。

花生叶面积指数精准快速监测方法研究

为探索适用于花生叶面积指数快速精准测量方法,基于田间调查实测数据,分别采用网格法、比叶重法、系数法、AutoCAD法以及扫描法等5种方法计算了花生不同生育时期的叶面积指数,并以基于扫描法的估算结果为对照,评价了基于其他4种监测方法估算结果的精度,并优化了系数法和比叶重法调查花生叶面积的关键技术指标。结果表明,比叶重法精度较高、监测速度较快、可操作性强,利用比叶重法监测花生叶面积指数,苗期、花针期、结荚期和饱果期叶片取样数分别为24、30、24和30片,相对误差分别为4.13%、4.07%、0.02%和0.13%,标准均方根误差为7.494%,适宜的干重比系数分别为150.00、143.26、187.58和157.20 cm^(2)/g。比叶重法是适宜于花生叶面积快速精准测量的方法。

Precise Molecular Weight Determination and Structure Characterization of End-functionalized Polymers:An NMR Approach via Combination of One-dimensional and Two-dimensional Techniques

We present here the application of one-dimensional and two-dimensional NMR techniques to characterize the structure of methoxyl end-functionalized polystyrenes （PS）. The peaks in 1H-NMR spectra corresponding to main-chain, side-chain and chain-end groups are assigned by 1H-1H gCOSY, 1H-13C gHSQC and gHMBC spectra. For the first time, the spin-lattice relaxation time （T1） of protons of the chain-ends is revealed to be affected more by polymer molecular weight （MW） than by the protons of the main-chains and the side-chains （almost independent from MW）. As a result, a much higher delay time （dl） for chain-ends （d1〉 20T1） is needed for quantitative NMR measurement when using end-group estimation method to obtain the MW of PS, which is in accordance with the value estimated by GPC. An improved method for the polymer MW determination is established, by combination of different NMR techniques to distinguish the peaks, and a large dl setting to achieve quantitative NMR analysis.

基于确定性系数的加权信息量法滑坡易发性评价--以贵州省兴义市为例

本文以贵州省兴义市滑坡地质灾害为研究对象,通过皮尔逊相关系数(PCC)对评价因子进行相关性分析,选取了坡度、平面曲率、地貌类型、工程岩组、距构造距离、斜坡结构、距水系距离7个评价因子,以确定性系数法计算各因子权重值,构建加权信息量模型,并与单一信息量模型和确定性系数模型的评价结果作对比分析。结果表明:加权信息量模型在高易发区和极高易发区的滑坡数占比为89.14%,AUC值为0.798,分别大于信息量模型的88.24%、0.788和确定性系数模型的85.52%、0.787。加权信息量模型评价结果更合理,精度更高,优于单一信息量模型和确定性系数模型。

盐菟丝子工艺优化和含量测定研究

目的:优选盐菟丝子最佳炮制工艺,并测定不同产地盐菟丝子中总黄酮与金丝桃苷含量,为后期临床应用提供参考依据。方法:采用紫外分光光度(UV)法与高效液相色谱(HPLC)法测定盐菟丝子总黄酮和金丝桃苷含量,通过熵权法计算其熵权值以计算其综合评分。采用三因素三水平法,考察炒制温度、炒制时间和氯化钠溶液质量分数3个因素,确定盐菟丝子最佳炮制工艺参数。用优选出的最佳工艺参数炮制12批不同产地菟丝子,进行含量测定,完善盐菟丝子质量标准研究。结果:盐菟丝子最优炮制工艺为1%氯化钠溶液浸泡2 h,100~110℃炒制15 min。用预测得出的最佳工艺条件平行试验3次,实际测得平均综合评分为93.57,与理论预测值96.61相对误差为3.14%,与响应面分析预测值接近。12批菟丝子经过炮制后总黄酮含量增加,金丝桃苷含量减少。盐炙品总黄酮含量在27.23~41.26 mg/g之间,金丝桃苷含量在2.72~3.49 mg/g之间。结论:Box-Behnken Design响应面优化盐菟丝子炮制工艺可靠稳定,具有实用价值。盐菟丝子总黄酮含量高于生品,金丝桃苷含量低于生品,建议在盐菟丝子质量标准中加入总黄酮作为含量测定指标。

天津地区盾构施工同步注浆浆液地层适配性

针对天津地区典型软土地层盾构隧道工程,对同步注浆的单液活性浆液配比进行分析,通过层次分析法、熵值法分析得到浆液性能指标权重。结果表明:水胶比、膨水比对浆液稠度影响较大;水胶比、胶砂比对浆液凝结时间影响较大;水胶比、膨水比对浆液泌水率影响较大;水胶比对浆液抗压强度影响较大;水胶比和胶砂比对浆液固结收缩率影响较大。通过博弈论组合权重法分析发现浆液凝结时间、抗压强度的权重最高,密度权重最低。通过优劣解距离法对浆液进行筛选,得到了适用于天津软土地层的同步注浆浆液配比。为天津地区盾构隧道同步注浆浆液配比提供借鉴。