Evaluation indices of sour flavor for apple fruit and grading standards

In order to establish grading standards of evaluation indices for sour flavor of apples, 10 indices of samples from 106 apple cultivars were tested, including： malic acid（Mal）, oxalic acid（Oxa）, citric acid（Cit）, lactic acid（Lac）, succinic acid（Suc）, fumaric acid（Fum）, total organic acids（To A, the sum of the six organic acids tested）, titratable acid（TiA）, acidity value（AcV）, and pH value. For most of the cultivars studied（85.8%）, the order of the organic acid contents in apples was Mal〉Oxa〉Cit〉Lac〉Suc〉Fum. Mal was the dominant organic acid, on average, accounting for 94.5% of To A. Among the 10 indices, the dispersion of pH value was the smallest with a coefficient of variation of only 8.2%, while the coefficients of variation of the other nine indices were larger, ranging between 31 and 66%. There were significant linear relationships between Mal and two indices（ToA and AcV） as well as between ToA and AcV. There were significant logarithmic relationships between pH value and four indices： Mal, TiA, ToA, and AcV. All the equations had very high fitting accuracy and can be used to accurately predict related indices. According to this study, Mal, ToA, and AcV of apple were normally distributed, TiA was close to normally distributed, whereas pH value had a skewed distribution. Using the fitted normal distribution curves, the grading standards of Mal, TiA, ToA, and AcV were established. The grading node values of pH value were obtained using the logarithmic relationship between pH value and Mal. The grading standards of these five indices can be used to evaluate the sour flavor of apple. This study provides a scientific basis for evaluating apple flavor and selecting apple cultivars.

A validated stability-indicating LC method for the separation of enantiomer and potential impurities of Linezolid using polar organic mode

Although a number of methods are available for evaluating Linezolid and its possible impurities, a common method for separation if its potential impurities, degradants and enantiomer in a single method with good efficiency remain unavailable. With the objective of developing an advanced method with shorter runtimes, a simple, precise, accurate stability-indicating LC method was developed for the determination of purity of Linezolid drug substance and drug products in bulk samples and pharmaceutical dosage forms in the presence of its impurities and degradation products. This method is capable of separating all the related substances of Linezolid along with the chiral impurity. This method can also be used for the estimation of assay of Linezolid in drug substance as well as in drug product. The method was developed using Chiralpak IA (250 mm 4.6 mm, 5 mm) column. A mixture of acetonitrile, ethanol, n-butyl amine and trifluoro acetic acid in 96:4:0.10:0.16 (v/v/v/v) ratio was used as a mobile phase. The eluted compounds were monitored at 254 nm. Linezolid was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. The degradation products were well resolved from main peak and its impurities, proving the stability-indicating power of the method. The developed method was validated as per International Conference on Harmonization (ICH) guidelines with respect to specificity, limit of detection, limit of quantification, precision, linearity, accuracy, robustness and system suitability.

Clinical implication of hematological indices in the essential hypertension

Prognostic value of haematological indices,especially red cell distribution width,neutrophil lymphocyte ratio and mean platelet volume,was reported with numerous investigations in miscellaneous cardiovascular settings.Their major prognostic value was linked to oxidative stress and inflammation since their level was correlated with major inflammatory markers such as high sensitive C-reactive protein and interleukins.Oxidative stress and chronic inflammation are also postulated as the main pathophysiologic mechanism of essential hypertension(HT) and its vascular complication.Recently,correlation between HT and haematological parameters was searched in numerous studies,which has made the topic more popular.Herein,we reveal the correlation between haematological indices and HT and we also demonstrate the clinical implication of this correlation.Impaired haematological parameters may strongly indicate hypertensive end-organ damage.

Sources and degradation of organic matter in the surface sediments of the Chukchi Sea:insights from amino acids

In the context of global warming and rapid environment change in the Arctic,the supply of organic matter(OM)has increased significantly and a large amount of OM are buried on the Arctic shelf.Studying the fate of OM in Arctic shelf sediments is crucial to understanding the global carbon sink.As a marginal sea of the Arctic Ocean,the Chukchi Sea is one of the most critical areas where OM is buried.Based on the surface sediment samples collected during the sixth Chinese National Arctic Research Expedition in the summer of 2014 and the SinoRussian joint Arctic Research Expedition in the summer of 2016,this study takes amino acids(AAs)as the primary tool to explore the source and degradation of OM in the surface sediments of the Chukchi Sea.This study shows that total hydrolyzable amino acid(THAA)concentrations(dry weight)are high,with a mean value of(32.7±15.8)μmol/g.Their spatial distribution is related to primary productivity,hydrodynamic conditions,sediment properties and other factors.The source of OM in the surface sediments of the Chukchi Sea is dominated by diatom-dominated marine productivity,with some input from terrestrial sources.Bacteria,as the main source of the D-enantiomer of AA(D-AA),not only have transforming effect on OM,but their cell walls and remnants likewise supply the OM pool.Based on a series of diagenetic indicators,we conclude that the OM in the surface sediments of the Chukchi Sea has undergone extensive degradation[DI(degradation index)=-0.59±0.44],and the degradation degree in the slope is higher than that in the shelf.This study uses AA to explore the sources and degradation of OM in the sediments of the Chukchi Sea,which facilitates our understanding of OM transport and transformation on the Arctic shelf.

蒙陕接壤区煤层顶板涌水水源智能判别方法

蒙陕接壤区煤炭高强度开采诱发的煤层顶板水害问题日益凸显,高效智能地判别煤层顶板涌水水源是顶板水害防治的关键。以蒙陕接壤区3个典型矿井为研究对象,将无机指标K^(+)+Na^(+)、Ca^(2+)、Mg^(2+)、Cl^(-)、SO_(4)^(2-)、HCO_(3)^(-)、TDS和有机指标UV_(254)、TOC、溶解性有机质(DOM)的荧光光谱作为判别指标,利用主成分分析法(PCA)对80组地下水水样数据进行主成分提取,提出一种人工鱼群算法(AFSA)改进随机森林(RF)的PCA-AFSA-RF顶板涌水水源智能判别方法。首先,建立PCA-RF判别模型,其准确率(A_(c))、精确率(P_(r))、召回率(R_(c))和F-measure指数(f_(1))分别达到了83.00%、83.17%、80.42%和79.57%;其次,通过AFSA对PCA-RF判别模型中决策树数目、树深和内部节点分裂所需的最小样本数进行寻优,在AFSA中引入遗传机制以避免陷入局部最优,建立基于PCA-AFSA-RF的煤层顶板涌水水源智能判别模型,该模型A_(c)、P_(r)、R_(c)、f_(1)分别达到92.18%、91.11%、87.58%和88.82%,较PCA-RF分别提高9.18%、7.94%、7.16%和9.25%,回代准确率达到97.50%;最后,利用该模型对12个矿井水水样进行判别,结果与现场实际相一致,表明AFSA改进后的PCA-RF模型具有更好的准确性和泛化能力。研究结果可为煤层顶板涌水水源的准确判别提供新方法。

畜禽粪便有机肥制备及其对土壤营养和西红柿品质的影响

以畜禽养殖粪便为主要原料,以玉米秸秆糠为调理剂,通过生物+纳米复合分子膜静态堆肥分别生产出符合标准NY 884—2021的品质优良有机肥(OF)产品及生物有机肥(BOF)。设计5组平行西红柿栽培试验,即CK组(不施肥)、CF组(100%硫酸钾型复合肥,400 kg/hm^(2))、COF组(80%硫酸钾型复合肥+20%OF 3000 kg/hm^(2))、CBO组(80%硫酸钾型复合肥+20%BOF 3000 kg/hm^(2))、COB组(70%硫酸钾型复合肥+20%OF 2000 kg/hm^(2)+10%BOF 1000 kg/hm^(2))5种施肥方式,试验结束后进行土壤有机质、全氮、速效钾等养分质量分数及果实品质指标,如可溶性糖、维生素C质量分数等的测定。结果发现:配施有机肥可使土壤中的速效氮、磷、钾相对提高,且化肥减施20%~30%对番茄产量影响不大。有机无机配施与单施化肥相比可显著提高果实品质,如提高可溶性糖和维生素C质量分数的同时有效降低可滴定酸及硝酸盐的质量分数(p<0.05)。通过对土壤耕层理化指标影响主成分进行分析,发现各施肥方式对土壤耕层理化指标影响由大到小排序依次为:CBO、COB、COF、CK、CF。采用冗余分析对土壤耕层理化指标与番茄品质相关性进行分析,发现土壤耕层6个理化指标均与番茄品质显著相关。

医疗机构健康素养测量指标体系的构建研究

目的 构建医疗机构健康素养(health care organization health literacy,HCOHL)测量指标体系。方法 于2021年6-12月,通过文献分析、半结构式访谈、专题小组讨论构建HCOHL测量指标体系初稿,借助专家咨询法形成HCOHL测量指标体系终稿,并采取层次分析法确定指标权重。结果 构建了我国HCOHL测量指标体系4项一级指标、22项二级指标、48项三级指标和64项测量项目。一级指标中,“医疗机构完善健康素养促进型管理体系”“员工主导健康素养促进”“健康素养促进型物质环境建设”和“外部合作”的权重分别为0.380 9、0.380 9、0.159 2和0.079 0。结论 该研究构建的HCOHL测量指标体系具有科学性和可行性,可为评价医疗机构健康素养促进情况提供工具参考,为践行《健康中国行动(2019-2030年)》提供借鉴。

复合酶在白羽肉鸡低蛋白日粮中的应用效果研究

试验旨在研究低蛋白日粮中添加复合酶对白羽肉鸡生长性能、血清生化和抗氧化指标、免疫功能和消化器官的影响。将288只1日龄白羽肉鸡随机分为6组,试验期42 d,试验配方设计1~21日龄和22~42日龄两阶段。对照组(CK组)饲喂常规蛋白日粮(两阶段粗蛋白水平分别为21.28%和19.04%);试验组均饲喂低蛋白日粮(两阶段粗蛋白水平较CK组分别降低0.97%和0.94%),试验1、2、3组全程分别添加200 mg/kg复合酶A(T1组)、200 mg/kg复合酶B(T2组)、300 mg/kg复合酶B(T3组),试验4组两阶段分别添加复合酶B 100、300 mg/kg;另设低蛋白日粮组(T0组)。试验结束时进行生长性能、血清生化和抗氧化指标、免疫功能和消化器官发育情况的测定分析。结果表明:T2、T3组21日龄活体重、42日龄活体重和欧洲生产效率指数均较高,T3组1~42日龄料重比低于其他组;CK组和T3组血清中尿素(UREA)含量显著低于T4组(P<0.05),T2组血清谷草转氨酶(AST)活性显著高于T1组外的其他组(P<0.05),T0、T1和T2组血清超氧化物歧化酶(SOD)含量显著低于T4组(P<0.05);T4组IgA、IgG和IgE显著高于T0组(P<0.05)。综上所述,在低蛋白日粮中添加复合酶能够提高白羽肉鸡指标和抗氧化能力,促进免疫器官和消化器官发育,提高免疫力。

褐藻寡糖对肉鸡生长性能、免疫器官指数、血清抗氧化指标和肠道健康的影响

本试验旨在研究褐藻寡糖(AOS)对肉鸡生长性能、免疫器官指数、血清抗氧化指标和肠道健康的影响。试验分别用100、200和800 U的褐藻胶裂解酶PDE9水解褐藻酸钠制备不同分子量的AOS,之后使用高效分子排阻色谱方法测定AOS的重均分子量,得出3种AOS的重均分子量分别为23981、5038和3766 u,依次标记为高分子量、中分子量和低分子量。然后选取体况一致和体重接近的1日龄爱拔益加(AA)雄性肉鸡280只,随机分为4组,每组7个重复,每个重复10只。对照组(CON组)饲喂基础饲粮,试验组分别在基础饲粮中添加200 mg/kg低分子量(AL组)、中分子量(AM组)和高分子量(AH组)的AOS。试验期40 d。结果表明:1)与CON组相比,AL组、AM组和AH组肉鸡40日龄体重均显著提高(P<0.05),1~40日龄和21~40日龄平均日增重(ADG)均显著提高(P<0.05);AL组和AM组肉鸡20日龄体重均显著提高(P<0.05),1~20日龄ADG均显著提高(P<0.05),1~20日龄料重比(F/G)均显著降低(P<0.05)。2)与CON组相比,AL组肉鸡20日龄肝脏指数显著降低(P<0.05);AM组和AH组肉鸡20日龄法氏囊指数均显著提高(P<0.05)。3)与CON组相比,AH组肉鸡空肠隐窝深度(CD)有降低趋势(P=0.084),空肠钠-葡萄糖共转运蛋白1(SGLT1)、锌转运蛋白1(ZnT1)、闭锁小带蛋白-1(ZO-1)、黏蛋白2(mucin-2)和闭合蛋白(occludin)的mRNA相对表达量均显著提高(P<0.05),空肠封闭蛋白-3(claudin-3)的mRNA相对表达量有提高趋势(P=0.081)。4)与CON组相比,AH组肉鸡盲肠扁桃体白细胞介素-10(IL-10)、白细胞介素-17(IL-17)和白细胞介素-1β(IL-1β)的mRNA相对量表达均显著降低(P<0.05)。5)与CON组相比,AH组肉鸡盲肠微生物β多样性差异有显著性趋势(P=0.055),且AH组盲肠拟杆菌属、瘤胃球菌科UCG-005、瘤胃梭菌属、考拉杆菌属、帕拉苏特氏菌属、弯曲杆菌属、鸡杆菌属和埃希氏-志贺氏菌属的相对丰度显著提高(P<0.05)。综上所述,饲粮中添加不同分子量AOS均能有效提高肉鸡生长性能;其中,高分子量AOS在制备中所需的酶量更少,生产成本相对更低,且能增强肉鸡免疫功能和改善肠道健康。

杏树抗寒性的研究进展

杏是蔷薇科最具经济价值的核果类作物之一。因其耐干旱、抗性强、易管理,常作为上山上坡、荒山绿化的先锋树种,在乡村振兴建设中的作用愈发凸显。但杏开花早,早春低温、晚霜等天气会对杏花、幼果造成一定的危害,降低坐果率,严重时造成绝产。温度已成为制约杏树产业发展的重要因子。作者对不同杏品种抗寒性、抗寒生理生化指标、花器官抗寒特性、外源激素及抗寒基因调控等方面进行系统综述,为深入杏抗寒机理研究、提升抗寒性提供参考和理论依据。

输变电工程表土剥离技术指标研究

表土是植物赖以生存的表层土壤,表土剥离和保护是水土保持的重要任务,研究输变电工程表土剥离厚度指标对指导绿色电网建设具有重要意义。将白鹤滩—江苏±800 kV特高压直流输变电工程沿线不同区域土壤有机质含量实测值与根据90 m分辨率全国土壤有机碳分布数据集得到的有机质含量预测值进行对比分析,发现预测值具有良好的可靠性,可以作为表土剥离等级划分的依据。将90 m分辨率全国土壤有机碳分布数据集参照全国第二次土壤普查中土壤有机质分级标准划分出土壤养分等级,利用ArcGIS软件绘制出全国范围的土壤养分分级图及表土剥离分级图,并参照表土利用方式确定出表土剥离厚度,即:有机质含量<10 g/kg的地区,土壤养分等级为5~6级,表土的剥离等级为2级,对应的剥离厚度为20~30 cm;而有机质含量≥10 g/kg的地区,土壤养分等级为1~4级,表土的剥离等级为1级,对应的剥离厚度根据需要加深10~20 cm。同时,针对水土保持区划一级区的表土剥离分级和水土保持功能,提出了适宜的表土剥离建议。

基于Anylogic的城市轨道交通客流仿真优化

轨道交通作为城市居民日常出行的主要交通方式之一,其车站的运营效率和服务水平对整个轨道交通线路网的顺畅运营起重要作用。针对我国地铁现存的问题,以轨道交通站点中的换乘站为研究对象,从乘客进站流畅性、优化方案的时效性、站内设施利用率3个方面对车站进行研究。利用Anylogic仿真软件建立济南地铁八涧堡换乘站的仿真模型,通过导入真实人流数据进行仿真模拟,针对各个瓶颈问题从站内设施布局和客流组织两方面提出科学合理的优化方案,并利用仿真实验对换乘方案进行检验。结果表明,通过研究站内人员、乘客、配套设施的集散状况,本文优化方案提高了车站面积和站内设施的利用率,消除了站内客流瓶颈,可有效缓解站内拥堵现象的产生并提高流线的流畅性,能为其他城市轨道交通换乘站优化提供决策性的支持。

住院病人多重耐药菌感染控制管理风险预警指标体系的构建

目的:构建住院病人多重耐药菌感染控制管理风险预警指标体系。方法:在前期研究的基础上,以风险认知理论和风险预警理论为指导,以结构-过程-结果三维模型为架构,采用文献阅读法、半结构化访谈法拟订住院病人多重耐药菌感染控制管理风险预警指标体系(草案),采用德尔菲专家函询法进一步完善住院病人多重耐药菌感染控制管理风险预警指标体系。结果:2轮专家函询问卷有效回收率均为100%,专家权威系数为0.950,专家函询的变异系数为0.025~0.227和0.028~0.224,肯德尔和谐系数为0.434和0.473(均P<0.001)。最终构建的住院病人多重耐药菌感染控制管理风险预警指标体系包括3项一级指标、8项二级指标、64项三级指标。结论:本研究构建的住院病人多重耐药菌感染控制管理风险预警指标体系具有科学性、可靠性、目的性和可量化性。

水环境生物监测技术的发展及应用研究

水环境生物监测技术作为理化监测的有效补充,随着我国生态文明建设步伐的不断推进,逐步趋向系统化与规范化。梳理了国内水环境生物监测技术的发展历程,分析了不同指示生物包括微生物、浮游植物、浮游动物、底栖动物、鱼类等的特点,跟踪了当前发展迅速的生物监测新兴技术,如光谱技术、图形识别技术等,最后对水环境生物监测技术作出了展望并提出发展建议。

西维来司他钠治疗脓毒症伴急性呼吸窘迫综合征的效果观察

目的:观察西维来司他钠治疗脓毒症伴急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)的效果。方法:将阳江市人民医院2023年6—12月收治的脓毒症伴ARDS患者总计60例,以随机数字表法分成两组,各30例,其中一组以常规治疗为对照组,另一组以常规治疗配合西维来司他钠治疗为研究组,均治疗7 d。比较两组血清学指标(炎症指标、血小板计数、血气指标),急性生理和慢性健康状况Ⅱ(acute physiology and chronic health evaluationⅡ,APACHEⅡ)评分、肺损伤评分,序贯器官衰竭估计(sequential organ failure assessment,SOFA)评分,机械通气时间及病死率。结果:治疗前,两组炎症指标、血气指标、血小板计数、APACHEⅡ评分、肺损伤评分、SOFA评分相比,差异均无统计学意义(P>0.05);治疗后,两组血清炎症指标、动脉血二氧化碳分压、APACHEⅡ评分、肺损伤评分、SOFA评分均较治疗前显著下降,且研究组均低于对照组,动脉血氧饱和度及血小板计数均较治疗前提升,研究组均高于对照组,差异均有统计学意义(P<0.05)。研究组机械通气时间短于对照组,差异有统计学意义(P<0.05)。两组的14 d病死率相比,差异无统计学意义(P>0.05)。结论:脓毒症伴急性呼吸窘迫综合征患者在接受西维来司他钠治疗,可显著减轻患者的血清炎症指标水平,改善血气指标,减轻肺损伤,缩短患者的机械通气时间,效果理想。

自热高温好氧消化工艺中污泥监测指标的变化规律研究

自热高温好氧消化工艺(ATAD)是目前处理城市污泥较为新颖的一种技术,该技术处理污泥效果好,处理成本低,处理15 d左右,基本可使污泥达到无害化的标准。对自热高温好氧消化工艺进行了介绍,并对工艺运行时污泥的挥发性有机物(VSS)、脱氢酶活性(DHA)、病原菌的灭活情况、总氮(TN)、总磷(TP)、蛋白质的变化进行监测,分析了这些指标的变化规律,以期为污泥后续资源化利用研究提供参考。

Identifying Indicator Species in Habitats Created by Coastal Structures

In this paper, three approachs were developed to find indicator species from the habitat created by coastal structures. These approachs consist of a model of species co-occurrence probability, a model of k-environmental factor probability and a composite model. Simultaneously, a case study was conducted in Hsinchu Fishing Port of north-western Taiwan. Based on the aforementioned models, three primary producer species, Ahnfeltiopsis flabelliformis, Chondrus ocellatus and Sarcodia montagneana, were chosen as the indicator species which had the highest co-occurrence probabilities and showed greater tolerance to more critical environment. It is imperative to understand how the three species under particular co-occurring conditions and environmental factors influence the composition of sessile assemblages in coastal water. The results indicate that for the purpose of increasing biodiversity, these models are feasible to find indicator species of artificial structures, and to help make it possible to design coastal structures based on biological considerations. This study provides an innovative approach for further advanced application in the artificial habitat of coast management.

Estimation of surface tension of organic compounds using quantitative structure-property relationship

A novel quantitative structure-property relationship(QSPR) model for estimating the solution surface tension of 92 organic compounds at 20 °C was developed based on newly introduced atom-type topological indices.The data set contained non-polar and polar liquids,and saturated and unsaturated compounds.The regression analysis shows that excellent result is obtained with multiple linear regression.The predictive power of the proposed model was discussed using the leave-one-out(LOO) cross-validated(CV) method.The correlation coefficient(R) and the leave-one-out cross-validation correlation coefficient(RCV) of multiple linear regression model are 0.991 4 and 0.991 3,respectively.The new model gives the average absolute relative deviation of 1.81% for 92 substances.The result demonstrates that novel topological indices based on the equilibrium electro-negativity of atom and the relative bond length are useful model parameters for QSPR analysis of compounds.

Antimicrobial Resistance Encountered in Garbage Collection Areas and Dumpsites in Nairobi, Kenya Using <i>Escherichia coli</i>and <i>Klebsiella</i>as Indicator Species

Dumpsites and garbage collection areas can act as reservoirs of highly resistant bacterial strains and facilitate the dissemination of Multidrug resistant strains to those living and work on or near the dumpsites and garbage collection areas. The objective of this study was to determine the potential of garbage collection areas and dumpsites in different parts of Nairobi as possible sources of resistant strains using E. coli and Klebsiella as indicator species. The study design was a cross-sectional survey. Sample collection was carried out at different days in seventeen different areas. A total of 126 samples were collected during the sampling period. The samples were then transported to the laboratory for analysis. The samples were cultured on MacConkey agar. Gram staining was done on discrete isolates based on colony characteristics. Biochemical tests were performed on colonies from primary cultures for final identification of the isolates. Antimicrobial disc susceptibility tests and pathogenicity tests were also carried out on the indicator isolates. A total of 121 E. coli and 165 Klebsiella were isolated from all the sampled sites. The highest bacterial burden was recorded from Muthurwa estate dumpsite, with a mean viable count of 8.2 × 1010 cfu/gm while the least was from Dandora dumpsite with a mean count of 1.1 × 1011 cfu/gm. Overall, gentamicin was the most effective antibacterial agent on Klebsiella and meropenem was the most effective on both E. coli and Klebsiella strains. The isolates showed high resistance to ampicillin, streptomycin, and trimethoprim-sulfamethoxazole. It is concluded that municipal waste dumpsites and garbage collection areas bear heavy burdens of potentially resistant bacteria which may constitute major public health hazards, not only to the immediate communities but also to the families of such site workers.