On the Harmonic Index of Triangle-Free Graphs

The harmonic index of a graph?G? is defined as where d(u) denotes the degree of a vertex u in G . In this work, we give another expression for the Harmonic index. Using this expression, we give the minimum value of the harmonic index for any triangle-free graphs with order n and minimum degree δ ≥ k for k≤ n/2? and show the corresponding extremal graph is the complete graph.

Increased free androgen index is associated with hypertension in premenopausal women

Objective: Increased testosterone and decreased sex hormone-binding globulin (SHBG) are associated with a number of adverse cardiovascular risk factors in postmenopausal women. The aim of this population-based study of women aged 25 to 50 was to assess the relationship between free androgen index (FAI) and cardiovascular risk factors in premenopausal women. Methods: A population-based survey of 396 premenopausal women with no hormonal treatment was undertaken as part of the Northern MONICA study. The study involved questionnaires, anthropometry and assays of testosterone and SHBG. Results: Increased FAI was associated with a number of cardiovascular risk factors in premenopausal women but this relationship was strongly affected by body mass index (BMI). After adjustment for age and BMI, FAI was significantly associated with increased systolic and diastolic blood pressures. Conclusion: Hyperandrogenism is associated with increased blood pressure and these findings emphasize the need to assess cardiovascular risk factors in women with hyperandrogenism of all ages.

玛湖凹陷二叠系风城组页岩油储层特征及高产主控因素

通过岩石薄片、扫描电镜、低温氮气吸附、高压压汞、岩心荧光、激光共聚焦显微镜和产液剖面等实验分析测试资料,对玛湖凹陷二叠系风城组储层特征及页岩油高产主控因素进行了详细研究。研究结果表明:①玛湖凹陷二叠系风城组页岩油储层类型可划分为砂岩类、白云岩类和泥岩类等,粉砂岩类储层以陆源碎屑沉积物为主,泥岩类储层以陆源-内源混积物为主,白云(灰)岩类储层以内源化学沉积为主;玛湖凹陷风城组粉砂岩类、白云岩类和泥岩类储层孔隙喉道尺寸依次减小,孔隙连通性依次变差。②玛湖凹陷风城组粉砂岩类储层含油性最好,其次是泥岩类储层,白云岩类储层含油性最差,孔径较大的孔隙和微裂缝中的游离油含量较高,孔径较小的孔隙中的吸附油含量较高。③玛湖凹陷风城组优质烃源岩和优质储层分别控制着页岩油的高产区域和高产层段,长英质矿物含量、有效孔隙度值、游离油孔隙度值、裂缝密度和脆性指数等均较高的储层是页岩油高产的有利层段。

自由贸易试验区新质生产力发展水平的测度与时空演变

从新劳动者、新劳动对象、新劳动资料三个维度构建新质生产力发展水平综合评价指标体系,运用熵权法测算2014—2022年17个自由贸易试验区的新质生产力水平,从指标、省份以及区域层面对研究结果进行分析,并进一步运用自然断点分类法和莫兰指数对自由贸易试验区新质生产力的时空特征以及空间相关性进行探究.研究结果表明,自由贸易试验区新质生产力水平总体上呈现上升趋势,地区间新质生产力水平存在差异性,东部地区发展水平高,西部地区发展水平低,同时自由贸易试验区新质生产力发展呈现空间正相关性,表现为高效型和低效型集聚.

Research of Climatic Zoning Index System of Red Cartridge Kiwifruit in Guizhou

The climate data of 84 meteorological stations in Guizhou from 1981 to 2010 was used,including the statistical data of daily precipitation,temperature,sunshine hours,evaporation,frost free period and so on. Using the equations of light and heat coefficient,light and heat index,latitude and temperature index,active accumulated temperature,effective accumulated temperature,aridity index,and arid-wet index,the red cartridge kiwifruit zoning index of Guizhou was analyzed and studied. The results showed that the zoning index system for the climatic characteristics of Guizhou mountainous area must be established in order to realize the variety regionalization of red cartridge kiwifruit in Guizhou mountainous area,and ten climatic factors were taken as climatic zoning indexes of red cartridge kiwifruit planting,including active accumulated temperature,effective accumulated temperature,annual average temperature,average temperature of July,light and heat coefficient,light and heat index,latitude and temperature index,frost free period,aridity index and arid-wet index. These indicators were giving a comprehensive evaluation for climate suitability conditions of red cartridge kiwifruit planting,and providing the scientific and reasonable basis for the promotion planting of red cartridge kiwifruit in mountain area of Guizhou.

Free fatty acids, glucose, and insulin in type 2 diabetes mellitus

Xu et al used the HOMA2 model to estimate theβ-cell function and insulin resistance levels in an individual from simultaneously measured fasting plasma glucose and fasting plasma insulin levels.This method is based on the assumption that the glucose-insulin axis is central for the metabolic activities,which led to type 2 diabetes.However,significant downregulation of both the NKX2-1 gene and the TPD52L3 gene force an increase in the release of free fatty acids(FFAs)into the blood circulation,which leads to a marked reduction in membrane flexibility.These data favor a FFA-glucose-insulin axis.The authors are invited to extend their study with the introduction of the saturation index(number of carbon-carbon double bonds per 100 fatty-acyl chains),as observed in erythrocytes.

基于Free Search的植被叶面积指数Logistic模型研究

针对利用归一化植被指数NDVI反演的植被叶面积指数LAI时间分辨率不足的问题,对传统Logistic模型进行了改进,并引入自由搜索(Free Search,FS)算法率定模型参数,建立了一种能够模拟植被逐日LAI的Logistic模型。首先,以NOAA-AVHRR提供的月NDVI作为反演植被LAI的基础数据,采用简单生物圈模型(Si B2)反演不同土地覆被类型下的植被月LAI;其次,借鉴传统Logistic模型模拟作物干物质的思路建立了一种改进的Logistic模型,并将FS单个动物每步探查行走的位置向量作为模型参数值,利用FS的动物群体迁移行为识别改进Logistic模型的最优参数,从而研究改进Logistic模型对植被月LAI的模拟效果。呼兰河流域的应用结果表明,利用FS识别参数的改进Logistic模型对呼兰河流域6种植被的月LAI模拟效果较好,为模拟植被LAI的逐日变化过程提供了一种新方法。

Improvements on Mean Free Wave Surface Modeling

Some new results of the modeling of mean free surface of waves or wave set-up are presented. The stream function wave theory is applied to incident short waves. The limiting wave steepness is adopted as the wave breaker index in the calculation of wave breaking dissipation. The model is based on Roelvink (1993), but the numerical techniques used in the solution are based on the Weighted-Average Flux (WAF) method (Watson et al., 1992), with Time-Operator-Splitting (TOS) used for the treatment of the source terms. This method allows a small number of computational points to be used, and is particularly efficient in modeling wave set-up. The short wave (or incident primary wave) energy equation is solved by use of a traditional Lax-Wendroff technique. The present model is found to be satisfactory compared with the measurements conducted by Stive (1983).

Element Free Gelerkin Method for 2-D Potential Problems

A meshfree method namely, element free Gelerkin (EFG) method, is presented in this paper for the solution of governing equations of 2-D potential problems. The EFG method is a numerical method which uses nodal points in order to discretize the computational domain, but where the use of connectivity is absent. The unknowns in the problems are approximated by means of connectivity-free technique known as moving least squares (MLS) approximation. The effect of irregular distribution of nodal points on the accuracy of the EFG method is the main goal of this paper as a complement to the precedent researches investigated by proposing an irregularity index (II) in order to analyze some 2-D benchmark examples and the results of sensitivity analysis on the parameters of the method are presented.

Vertical variations and composition of dissolved free amino acid in the seawater of the Yap Trench in the western Pacific Ocean

The composition and concentration of dissolved free amino acid(DFAA)of seawater samples collected in May 2016 from the surface to the hadal zone of the northern region of the Yap Trench were analyzed by pre-column derivatization of o-phthalaldehyde.Results show that the average concentration of DFAA in the study area was 0.47±0.36μmol/L.In different sampling stations,the concentrations of DFAA with water depth showed complex variation patterns.At the sediment-seawater interface,the concentrations of DFAA in the western side of the trench were obviously higher than that in its eastern side.In the study area,there were no significant correlations between the concentrations of DFAA and the environmental parameters such as concentrations of chlorophyll a(Chl a),dissolved oxygen(DO),pH,and dissolved inorganic nitrogen(DIN),indicating that the concentrations of DFAA in seawater of the trench are affected by many factors,such as photosynthesis,respiration,temperature,pressure,illumination,and circulation.The dominant DFAA are similar in different water layers of sampling stations,including aspartic acid(Asp),glutamic acid(Glu),glycine(Gly),and serine(Ser).The composition of different amino acids,and the relative abundance of acidic,basic,and neutral amino acids might be related to the sources and consumption of various amino acids.Nine pairs of amino acids in the DFAA showed significantly positive relationship by correlation matrix analysis,suggesting that they might share similar biogeochemical processes.The degradation index(DI)of the DFAA in seawater of the Yap Trench could reflect the degradation,source,and freshness of DFAA in the trench to some extents.This is a preliminary study of amino acids from sea surface to hadal zone in the ocean,more works shall be done in different trenches to reveal their biogeochemical characte ristics in extreme marine environme nts.

Phosphor-free white light-emitting diodes

The multiple color-matching schemes that could improve the color rendering index for phosphor-free white LEDs are discussed. Then we review a few of the recent research directions for phosphor-free white LEDs, which include the development of monolithic GaN-based white LEDs and hybrid integrated GaN-based and A1GalnP-based white LEDs. These development paths will pave the way toward commercial application of phosphor-free white LEDs in the coming years.

微波辐射无皂乳液聚合法制备单分散交联PMMA微球及其性能研究

采用无皂乳液聚合法,以二乙烯苯为交联剂,氯化钾为电解质,过硫酸钾为引发剂,在微波辐射条件下制备了聚甲基丙烯酸甲酯(PMMA)微球。研究了过硫酸钾和氯化钾的物质的量浓度对PMMA微球的平均粒径和多分散性指数的影响,分析了微波功率、搅拌速度与PMMA微球形貌和粒径的关系。检测了不同pH值时PMMA乳液的电动(Zeta)电位,表明PMMA表面产生负电荷,使PMMA微球呈现稳定的分散状态。制备的PMMA呈现类球形,粒径为100~400 nm,在过硫酸钾物质的量浓度为5.69×10^(-3)mol/L及氯化钾物质的量浓度为1.03×10^(-2)mol/L时,微球的多分散性指数<0.1。原子力显微镜检测了最优工艺条件下,PMMA微球的力—位移曲线并分析了其弹性力学性能。

Space-Energy Duality Generalized 4-Index Einstein Field Equation

The introduction of a new concept of space-energy duality serves to extend the applicability of the Einstein field equation in the context of a 4-index framework. The utilization of the Weyl tensor enables the derivation of Einstein’s equations in the 4-index format. Additionally, a two-index field equation is presented, comprising a conventional Einstein field equation and a trace-free Einstein equation. Notably, the cosmological constant is associated with a novel concept that facilitates the encoding of space and energy information, thereby enabling the recognition of mutual interactions between space and energy in the presence of gravitational forces, as dictated by Einstein’s field equations (EFE) and Trace-Free Einstein Equation (TFE).

痰湿型多囊卵巢综合征患者游离睾酮指数水平与临床特征的差异及相关性分析

目的 探讨痰湿证与非痰湿证多囊卵巢综合征(polycystic ovarian syndrome, PCOS)患者游离睾酮指数(free testosterone index, FAI)与不同临床特征的差异及相关性。方法 基于临床科研信息一体化平台收集病例资料,回顾性纳入2019年9月~2021年1月黑龙江中医药大学第一附属医院收治的1041例PCOS患者。按中医诊断标准分为痰湿组(n=658)和非痰湿组(n=383),记录各项指标并统计分析各项指标与FAI的相关性,以分析不同中医证型FAI的影响因素。结果 痰湿组PCOS患者FAI、体重、腰围、臀围、腰臀比(waist-to-hip ratio, WHR)、空腹血糖(fasting plasma glucose, FPG)、30min葡萄糖、空腹胰岛素(fasting insulin, FINS)、30min胰岛素、胰岛素抵抗指数(insulin resistance of homeostasis model assessment, HOMA-IR)、甘油三酯(triglyceride, TG)、总胆固醇(total cholesterol, TC)、低密度脂蛋白胆固醇(low-density lipoprotein-cholesterol, LDL-C)、载脂蛋白B(apolipoprotein B, ApoB)、ApoB/ApoA等临床指标值高于非痰湿组(P<0.05)。在痰湿组PCOS患者中,FAI与卵泡生成素(follicle-producing hormone, FSH)、泌乳素(prolactin, PRL)、性激素结合球蛋白(sex hormone-binding globulin, SHBG)、高密度脂蛋白胆固醇(high-density lipoprotein-cholesterol, HDL-C)、载脂蛋白A(apolipoprotein A, ApoA)呈负相关,与收缩压、舒张压、体重、体重指数(body mass index, BMI)、腰围、臀围、WHR、睾酮(testosterone, T)、雄烯二酮(androstenedione, AND)、60min葡萄糖、120min葡萄糖、FINS、30min胰岛素、60min胰岛素、120min胰岛素、180min胰岛素、HOMA-IR指数、TG、ApoB/ApoA呈正相关(P<0.05)。在非痰湿组PCOS患者中,FAI与PRL、SHBG呈负相关,与舒张压、体重、BMI、腰围、T、硫酸脱氢表雄酮(dehydroepiandrosterone sulfate, DHEAS)、AND、60min葡萄糖、120min葡萄糖、FINS、60min胰岛素、120min胰岛素、180min胰岛素、ApoB、HOMA-IR指数呈正相关(P<0.05)。结论 痰湿组与非痰湿组PCOS患者的FAI等研究指标水平存在显著差异,痰湿组PCOS患者的FAI水平高于非痰湿组。痰湿组PCOS患者FAI水平与肥胖、糖脂代谢水平等具有明显的相关性,其因果关系需进一步探究。

t-PSA及其衍生指标PHI和PI-RADS评分对前列腺癌诊断效能的评价

目的探讨总前列腺特异性抗原(t-PSA)、游离前列腺特异性抗原(f-PSA)占t-PSA的百分比(f-PSA/t-PSA%)、前列腺健康指数(PHI)和前列腺影像及报告数据系统(PI-RADS)评分对前列腺癌的诊断效能。方法选取2022年7月—2024年2月吉林大学第一医院经病理检查确诊的前列腺疾病患者277例,按病理诊断分为良性疾病组(143例)、前列腺癌组(134例),按t-PSA水平分为t-PSA<20 ng·mL^(-1)组(147例,其中良性疾病100例、前列腺癌47例)、t-PSA≥20 ng·mL^(-1)组(130例,其中良性疾病43例、前列腺癌87例)。检测所有患者血清t-PSA、f-PSA和前列腺特异性抗原同源异构体2(p2PSA),计算f-PSA/t-PSA%,并进行PIRADS评分。采用Logistic回归分析评估前列腺癌发生的影响因素。采用受试者工作特征(ROC)曲线评价各项指标诊断前列腺癌的效能。结果前列腺癌组t-PSA和PHI显著高于良性疾病组(P<0.001),f-PSA/t-PSA%显著低于良性疾病组(P<0.001);PI-RADS评分≥4分所占比例高于良性疾病组(P<0.001)。t-PSA、f-PSA/t-PSA%、PHI和PI-RADS评分诊断前列腺癌的曲线下面积(AUC)分别为0.752、0.633、0.913、0.881。PHI和PI-RADS评分是前列腺癌发生的独立危险因素[比值比(OR)值分别为1.035、2.520,95%可信区间(CI)分别为1.021~1.049、1.672~3.800,P<0.001]。在t-PSA<20 ng·mL^(-1)组中,与良性疾病患者比较,前列腺癌患者PHI和PI-RADS评分≥4分所占比例均显著升高(P<0.001),f-PSA/t-PSA%降低(P<0.05),t-PSA水平差异无统计学意义(P>0.05)。在t-PSA≥20 ng·mL^(-1)组中,与良性疾病患者比较,前列腺癌患者t-PSA水平、PHI和PI-RADS评分≥4分所占比例均显著升高(P<0.001),f-PSA/t-PSA%差异无统计学意义(P>0.05)。t-PSA、f-PSA/t-PSA%、PHI和PI-RADS评分单项检测诊断t-PSA<20 ng·mL^(-1)前列腺癌的AUC分别为0.561、0.611、0.836、0.834;4项指标联合检测的AUC最高,为0.900;单项检测诊断t-PSA≥20 ng·mL^(-1)前列腺癌的AUC分别为0.822、0.520、0.963、0.875,联合检测中t-PSA+f-PSA/t-PSA%+PHI和t-PSA+f-PSA/t-PSA%+PHI+PI-RADS评分的AUC分别为0.970、0.972。结论对于t-PSA<20 ng·mL^(-1)的患者,t-PSA、f-PSA/t-PSA%、PHI和PIRADS评分联合检测可提高前列腺癌的检出率。对于t-PSA≥20 ng·mL^(-1)的患者,PHI是诊断前列腺癌较好的指标,t-PSA、f-PSA/t-PSA%和PHI联合检测可提升诊断效能。

数据流动与服务贸易出口--基于数据要素视角的理论与实证分析

数据能否自由流动对数据作为投入要素的价值释放、数字经济发展效益及服务贸易发展具有重要影响。本文首先将数据要素引入生产函数构建理论模型,以“数据流动限制”来衡量数据流动程度,通过理论推导发现,数据自由流动会通过提高生产率、降低合规成本、降低搜寻成本等三条渠道促进服务贸易出口。其次,测算2000—2014年39个国家21个服务行业的数据流动限制指数,并将其作为影响服务贸易出口的核心解释变量进行实证研究。结果表明,数据流动限制对服务贸易出口产生显著的负向影响,反之即表明数据自由流动会促进服务贸易出口。机制检验表明,提高生产率、降低合规成本、降低搜寻成本是数据自由流动促进服务贸易出口的重要渠道。异质性分析显示,在不同数据监管模式、不同发展水平的国家及不同类型服务业中,数据自由流动对服务贸易出口产生不同程度的异质性影响。

镜疝修补术与开放式无张力疝修补术治疗腹股沟疝疗效对比研究

目的对比研究镜疝修补术治疗腹股沟疝的临床疗效。方法方便选取2019年6月—2023年10月启东市第二人民医院收治的123例腹股沟疝患者,采用密闭信封法分为对照组(n=61)、研究组(n=62)。对照组行开放式无张力疝修补术,研究组行镜疝修补术。比较两组围术期指标及并发症发生率。结果研究组手术时间长于对照组,其他指标优于对照组,差异有统计学意义(P均<0.05)。研究组并发症发生率(3.23%)低于对照组(14.75%),差异有统计学意义(χ^(2)=4.768,P<0.05)。结论镜疝修补术治疗腹股沟疝的效果优于传统术式,该手术方式具有微创性,对患者机体损伤较轻,同时,该种术式能够降低并发症风险,具有较高的安全性,有利于患者术后机体康复,从而改善患者预后。

江苏省部分地区成年人脂肪质量分布特征分析

目的:探究江苏省部分地区不同性别成年人脂肪质量随年龄增长的变化情况以及不同年龄段人群体质量指数(body fat index,BMI)和脂肪质量之间的关系。方法:收集2019年9月至2021年2月江苏省南京市、淮安市以及无锡市的体检人群数据,对符合纳入标准人群进行体格检查和体成分检测,并分析其脂肪质量随年龄变化情况。结果:共收集2115名志愿者的基本信息,排除信息不全者46名,共纳入2069名进行研究分析。30岁以上成年人去脂体质量(fat free mass,FFM)随着年龄的增长呈现下降的趋势;30岁以上成年人的体脂肪量(body fat mass,BFM)、体脂百分比(percentage of body fat,PBF)、腰臀比(waist-hip ratio,WHR)和体脂指数(fat mass index,FMI)随着年龄的增长均呈现上升趋势,BFM、PBF和去脂体质量百分比(percentage of fat free mass,PFFM)在40岁出现显著上升,FFM和去脂体质量指数(fat free mass index,FFMI)在60岁开始出现显著下降。男性FMI在40岁出现显著上升,女性FMI从60岁出现显著上升。全年龄段成年人FFM随着BMI和腰围水平的升高呈上升趋势。结论:随着年龄的增长男性和女性的BFM、PBF和WHR均呈现上升趋势。各年龄段成年男性FFM显著高于女性,女性BFM、FMI、PBF和内脏脂肪面积显著高于男性。全年龄段成年人FFM随着BMI和WHR升高呈上升趋势。

排酸方式和时间对高档育肥安格斯牛肉品质的影响

为探究高档牛肉的排酸技术,本研究选取12条高档育肥安格斯牛背最长肌肉为原料,通过干式和湿式排酸,选择3、5和7 d三个时间点,并对牛肉基本理化指标、游离氨基酸和挥发性风味物质综合分析。结果显示,干式排酸3和5 d牛肉pH显著低于湿式排酸,干式排酸7 d牛肉pH显著高于湿式排酸(P<0.05);干式排酸3 d牛肉剪切力显著低于湿式排酸(P<0.05)。干式和湿式排酸7 d牛肉中丝氨酸、缬氨酸、蛋氨酸、异亮氨酸、酪氨酸、亮氨酸、苯丙氨酸、精氨酸、赖氨酸、甜味氨基酸、苦味氨基酸及总游离氨基酸的含量均显著提高(P<0.05);干式排酸7 d牛肉中天冬氨酸、谷氨酸、丙氨酸和鲜味氨基酸的含量显著高于湿式排酸(P<0.05)。干式排酸和湿式排酸最主要的挥发性风味贡献物质均为壬醛、正辛醛和1-辛烯-3-醇;湿式排酸特有的挥发性风味物质为庚醛,干式排酸7 d牛肉中正辛醛、苯乙醛、十一醛、肉豆蔻醛和柠檬烯相对含量显著高于湿式排酸(P<0.05)。综上所述,排酸7 d有利于提升高档育肥安格斯牛肉风味的丰富度,干式排酸较湿式排酸对高档牛肉风味改善作用更佳。

控制无麸质食品血糖生成指数的策略

近年来,随着乳糜泻和慢性代谢性疾病患者数量的增加,对低血糖生成指数(GI)无麸质食品的需求也不断上升。文章综述了原料如谷物(大米、小米、燕麦)、伪谷物(荞麦、藜麦、苋菜籽)、豆类等、外源改良剂如蛋白质、脂质、膳食纤维、抗性淀粉、多酚等和加工方式对无麸质食品GI的影响;在此基础上,指出了开发低GI无麸质食品所面临的挑战,并展望了该领域的发展前景,旨在为生产营养均衡和口感良好的低GI无麸质食品提供参考,并满足乳糜泻患者多方面消费需求。