Intervention effect of chewing sugar-free gum on xerostomia in hemodialysis patients: A meta-analysis

目的:采用Meta分析的方法,评价咀嚼无糖口香糖对血液透析患者口腔干燥症干预的效果。方法:检索中国知网、万方、维普、中国生物医学、Pubmed、Embase、Cochance、Web of science、Ovid及CINAHL数据库中有关咀嚼无糖口香糖对血液透析患者口腔干燥症干预效果的随机对照试验或半随机临床试验。将符合纳入、排除标准的研究进行数据提取和质量评价后,使用Review Manager 5.3软件对结局指标进行Meta分析。结果:共纳入5项研究,包括237名患者。结果显示,咀嚼无糖口香糖能改善患者的口干症状[MD=-2.12,95%CI(-2.53,-1.71),P<0.001];但对患者透析间的口渴症状[MD=-1.57,95%CI(-3.41,0.27),P=0.09]和体重增加[MD=-0.38,95%CI(-1.02,0.27),P=0.25]没有影响。结论:咀嚼无糖口香糖对血液透析患者的口干症状有所改善,但对患者透析间口渴症状和体重增加无影响。但由于本研究纳入的文献数量较少,且文献质量不高,因此仍需开展大样本、多中心的高质量随机对照试验,以进一步探讨咀嚼无糖口香糖对血液透析患者口腔干燥症的干预效果。

Enhancement of the Antigenotoxic and Antioxidant Actions of Eugenol from Spice Clove and the Stabilizer Gum Arabic on Colorectal Carcinogenesis

Spices are defined as any aromatic condiment of plant origin used to alter the flavor and aroma of foods. Besides flavor and aroma, many spices have antioxidant activity, mainly related to the presence in cloves of phenolic compounds, such as flavonoids, terpenoids and eugenol. In turn, the most common uses of gum arabic are in the form of powder for addition to soft drink syrups, cuisine and baked goods, specifically to stabilize the texture of products, increase the viscosity of liquids and promote the leavening of baked products (e.g., cakes). Both eugenol, extracted from cloves, and gum arabic, extracted from the hardened sap of two species of the Acacia tree, are dietary constituents routinely consumed virtually throughout the world. Both of them are also widely used medicinally to inhibit oxidative stress and genotoxicity. The prevention arm of the study included groups: Ia, IIa, IIIa, Iva, V, VI, VII, VIII. Once a week for 20 weeks, the controls received saline s.c. while the experimental groups received DMH at 20 mg/kg s.c. During the same period and for an additional 9 weeks, the animals received either water, 10% GA, EUG, or 10% GA + EUG by gavage. The treatment arm of the study included groups Ib, IIb, IIIb e IVb, IX, X, XI, XII). Once a week for 20 weeks, the controls received saline s.c. while the experimental groups received DMH at 20 mg/kg s.c. During the subsequent 9 weeks, the animals received either water, 10% GA, EUG or 10% GA + EUG by gavage. The novelty of this study is the investigation of their use alone and together for the prevention and treatment of experimental colorectal carcinogenesis induced by dimethylhydrazine. Our results show that the combined use of 10% gum arabic and eugenol was effective, with antioxidant action in the colon, as well as reducing oxidative stress in all colon segments and preventing and treating genotoxicity in all colon segments. Furthermore, their joint administration reduced the number of aberrant crypts and the number of aberrant crypt foci (ACF) in the distal segment and entire colon, as well as the number of ACF with at least 5 crypts in the entire colon. Thus, our results also demonstrate the synergistic effects of 10% gum arabic together with eugenol (from cloves), with antioxidant, antigenotoxic and anticarcinogenic actions (prevention and treatment) at the doses and durations studied, in the colon of rats submitted to colorectal carcinogenesis induced by dimethylhydrazine.

Effect of Gum Arabic from Acacia senegal var. kerensis as an Improver on the Rheological Properties of Wheat Flour Dough

Dough improvers are substances with functional characteristics used in baking industry to enhance dough properties. Currently, the baking industry is faced with increasing demand for natural ingredients owing to increasing consumer awareness, thus contributing to the rising demand for natural hydrocolloids. Gum Arabic from Acacia senegal var. kerensis is a natural gum exhibiting excellent water binding and emulsification capacity. However, very little is reported on how it affects the rheological properties of wheat dough. The aim of this study was therefore, to determine the rheological properties of wheat dough with partial additions of gum Arabic as an improver. Six treatments were analyzed comprising of: flour-gum blends prepared by adding gum Arabic to wheat flour at different levels (1%, 2% and 3%), plain wheat flour (negative control), commercial bread flour and commercial chapati flour (positive controls). The rheological properties were determined using Brabender Farinograph, Brabender Extensograph and Brabender Viscograph. Results showed that addition of gum Arabic significantly (p chapati. These findings support the need to utilize gum Arabic from Acacia senegal var. kerensis as a dough improver.

Effect of defatted flaxseed gum powder addition on the quality of sesame paste

The study explored the influence of defatted flaxseed gum powder(DFGP) on the stability and quality of sesame paste by measuring and analyzing its composition, color, texture, particle size, centrifugal oil separation rate,rheological properties, and microstructure. The results showed that the moisture and polysaccharide content of sesame paste was increased as the DFGP increased. Additionally, the hardness, gumminess, and chewiness of the sesame paste was improved, while the presence of particles with small particle size(1–100 μm) was decreased.The rate of oil precipitation was reduced by 28.99% when the amount of DFGP was 6%. The sesame paste samples exhibited pseudoplastic behavior, demonstrating shear thinning. As the shear rate increased, the apparent viscosity of sesame paste gradually decreased. Both the storage modulus(G’) and the loss modulus(G’’) increased as the shear frequency increased. The microstructure observation revealed that protein and oil were evenly distributed in the sesame paste system, and the addition of DFGP enhanced the bonding between oil and protein.This study can provide valuable references for high-quality sesame paste products in the food industry.

基于GUM的麻醉机计量特性的测量不确定度评定

目的:采用GUM法对麻醉机计量特性的测量不确定度进行评定。方法:根据GUM法流程及JJF(鄂)61-2020《麻醉机校准规范》中测量标准,分别对麻醉机的潮气量和输出麻醉气体浓度进行不确定度评定。结果:在容量控制(VCV)模式,设置麻醉机潮气量为400mL,则相对示值误差的扩展不确定度为U_(rel)=3.48%(k=2);设置麻醉机输出麻醉气体浓度为1.5%,则示值误差的扩展不确定度为U_(rel)=0.164%(k=2)。结论:基于GUM法测量不确定度评定,可完成麻醉机计量特性的不确定评定。

基于GUM法和控制图法评定绿茶中三唑磷残留量测定的不确定度

采用气相色谱-串联质谱法(GC-MS/MS)测定绿茶中三唑磷的残留量并进行不确定度评定。依据ISO/IEC Guide 98-3:2008(GUM法)和GB/T 27411-2012《检测实验室中常用不确定度评定方法与表示》(控制图法)对检测结果进行不确定度的分析与量化。结果表明,GUM法和控制图法的评定结果分别为(0.112±0.012)mg/kg,k=2和(0.108±0.018)mg/kg,k=2。GUM法的不确定度主要来源是质量浓度和仪器稳定性,其各自占总不确定度的38.9%和24.7%。控制图法只对检测结果进行统计分析,简单易操作,考察的是检测结果的长期趋势,可在日常检测工作中的内部质量控制应用中得到实施,而GUM法适用于复检样品或客户对不确定度有要求时的评定,计算复杂,但可在短时间内获得不确定度评定结果。

基于GUM法的压缩机性能测试不确定度分析

因在压缩机性能测试过程中直接测量得到的各项参数及其不确定度均会对最终结果产生不同程度的影响,为了找到影响结果的主要因素并合理改善这种情况,本文依据GB/T 5773-2016对某涡旋式压缩机进行了性能测试,并基于GUM法对测量结果进行了不确定度分析和敏感度分析。结果表明:压缩机的制冷量测试结果为108.26 kW,合成标准不确定度为0.58 kW,扩展不确定度的相对值为1.07%;对测量结果不确定度产生最大影响的因素是温度仪器的精度,精度提高1倍,可使测量结果的不确定度降低21.15%。

石油石化检测结果测量不确定度GUM评定法和典型实例

该文解析石油石化行业的实验室对数据型检测结果不确定度GUM评定法(一种常用的评定方法),并对常见问题进行梳理,帮助技术人员快速学习和掌握检测结果测量不确定度GUM评定法。

Xanthan Gum—Bio-Based Raw Material for Wood Adhesive

Due to their lower environmental impact, ease of accessibility, low cost, and biodegradability, bio-renewable sources have been used extensively in the last several decades to synthesize adhesives, substituting petrochemical-based adhesive. Vegetable oils (including palm, castor, jatropha, and soybean oils), lactic acid, potato starch, and other bio-renewable sources are all excellent sources for the synthesis of adhesives that are being taken into consideration for the synthesis of “eco-friendly” adhesives. Due to their widespread use, accessibility, affordability, and biodegradability, biobased raw materials like carbohydrates used to synthesize wood and wood composite adhesive have gradually replaced petrochemical-based adhesive. Recently, xanthan gum, a naturally occurring polymer, has drawn the interest of scientists as a potentially petroleum source replacement. It possesses specific rheological characteristics, excellent water solubility, and stability to heat, and can be used as a binder, thickener, suspending agent, and stabilizer. Xanthan gum increases the adhesive strength in addition to increasing the viscosity of water-soluble adhesives. This article discusses xanthan gum as a potential substitute for traditional raw materials derived from petroleum that is used as a raw material for adhesives.

Physical and emulsifying properties of pea protein:influence of combined physical modification by flaxseed gum and ultrasonic treatment

This study characterized and compared the physical and emulsifying properties of pea protein(PP)and its modified proteins(ultrasound treated-PP(PPU),flaxseed gum(FG)treated PP(PPFG)and ultrasound treated-PPFG(PPFGU)).The results showed FG triggered the formation of loosely attached complex with PP via physical modification under gentle magnetic stirring at pH 7.0,while ultrasound played an important role in reducing protein size,increasing surface hydrophobicity and molecular fluidity onto oil-water interface.So ultrasound further enhanced the interaction of PP with FG,and produced the PPFGU complex with smaller droplet size,higherζ-potential and lower turbidity.Further,combination of FG and ultrasound improved the physical properties of PP with higher viscosity,stiffer gels(defined as higher elastic modulus),stronger hydrophobic properties,better thermal stability,and fast protein absorption rate.Therefore,the PPFGU coarse emulsion performed highest emulsifying activity index(EAI)and emulsion stability index(ESI)that the stabilized nanoemulsion obtained smallest droplet size,higherζ-potential,and longest storage stability.The combination of FG and ultrasonic treatment will be an effective approach to improving the emulsifying property and thermal stability of PP,which can be considered as a potential plant-based emulsifier applied in the food industry.

Temperature/salt tolerance and oil recovery of xanthan gum solution enhanced by surface-modified nanosilicas

Amide-and alkyl-modified nanosilicas(AANPs)were synthesized and introduced into Xanthan gum(XG)solution,aiming to improve the temperature/salt tolerance and oil recovery.The rheological behaviors of XG/AANP hybrid dispersions were systematically studied at different concentrations,temperatures and inorganic salts.At high temperature(75C)and high salinity(10,000 mg,L1 NaCl),AANPs increase the apparent viscosity and dynamic modulus of the XG solution,and XG/AANP hybrid dispersion exhibits elastic-dominant properties.The most effective concentrations of XG and AANP interacting with each other are 1750 mg·L^(-1) and 0.74 wt%,respectively.The temperature tolerance of XG solution is not satisfactory,and high temperature further weakens the salt tolerance of XG.However,the AANPs significantly enhance the viscoelasticity the XG solution through hydrogen bonds and hydrophobic effect.Under reservoir conditions,XG/AANP hybrid recovers approximately 18.5%more OOIP(original oil in place)than AANP and 11.3%more OOIP than XG.The enhanced oil recovery mechanism of the XG/AANP hybrid is mainly increasing the sweep coefficient,the contribution from the reduction of oil-water interfacial tension is less.

GUM法与Top-down精密度法评定白酒中铅的不确定度比较

目的:比较GUM法与Top-down精密度法评定白酒中铅的不确定度。方法:按照《食品安全国家标准食品中铅的测定》(GB 5009.12—2017)第一法石墨炉原子吸收光谱法,对质控样和能力验证样进行测定。结果:GUM法评定得到白酒质控样中铅含量的测定值在0.613~0.656 mg·kg^(-1);Top-down精密度法评定得到白酒质控样中铅含量的测定值在0.596~0.673 mg·kg^(-1);均处于白酒质控样特性值范围0.568~0.694 mg·kg^(-1)内。结论:GUM法与Top-down精密度法均能有效评定白酒中铅的不确定度。当遇到过程较为烦琐的检测,Top-down精密度法评定不确定度较为简单快速、便于操作。

Mechanical properties of dredged soil reinforced by xanthan gum and fibers

Biopolymers have become popular in geotechnical engineering as they provide a carbon-neutral alternative for soil solidification.Xanthan gum(XG)and jute fiber(JF)were selected to solidify the Yellow River dredged soil.The mechanical behavior of solidified dredged soil(SDS)was investigated using a series of uniaxial compression and splitting tension tests at different XG and JF contents and fiber lengths.The results indicate that on the 28th day,the unconfined compressive strength(UCS)values of SDS samples reached 2.83 MPa and splitting tensile strength(STS)of 0.763 MPa at an XG content of 1.5%.When the JF content was greater than 0.9%,the STS of the SDS samples decreased.This is because that the large fiber content weakened the cementation ability of XG.The addition of JF can significantly increase the strain at peak strength of SDS samples.There is a linear relationship between the UCS and STS of the dredged soils solidified by XG and JF.Microanalysis shows that the strength of SDS samples was improved mainly via the cementation of XG itself and the network structure formed by JF with soil particles.The dredged soil reinforced by XG and JF shows better mechanical performance and has great potential for application.

基于GUM方法的聚丙烯酰胺钾盐钾含量不确定度研究

作为实验室认可质量控制中的关键环节,测量不确定度是检测过程中各因素对检测结果造成不确定性的定量表征,亦是实验室对检测结果进行合格性评判的依据。阐述了GUM法评定不确定度的一般流程,并以钻井液用聚丙烯酰胺钾盐钾含量的测定为例,采用GUM法对钾含量的不确定度进行了定量表征、定性分析。结果显示,钾含量不确定度为0.5%,其中滴定度引入的不确定度分量为钾含量不确定度的主要来源,降低测量滴定度所涉及称量、移液、滴定等步骤产生的随机效应对测量结果的影响是提升钾含量检测数据质量、实现实验室内部质量控制和质量改进的关键。

基于蒙特卡洛法与GUM评定测量不确定度的对比分析

测量不确定度的准确评定是测量结果有效可靠的重要依据,是仪器仪表质量保证的重要指标。常用的测量不确定度评定法(GUM)利用线性化模型对不确定度进行传播,当误差模型为非线性或较为复杂时,容易造成评定结果不准确。本文以核电厂常用的压力表为例,采用蒙特卡洛测量不确定度评定法(MCM)对其测量误差进行不确定度评定,重点研究了MCM的评定方法与步骤,利用MATLAB模拟大量样本对概率密度进行传播,从而得到不确定度结果,最后运用MCM对GUM的评定结果进行验证。结果表明,MCM对压力表测量误差的不确定度评定更为精确可靠,值得应用和推广。

基于CT技术的黄原胶加固土干湿循环条件下力学性能和微观结构劣化机制研究

干湿循环对岩土体的工程特性具有重要影响。采用CT扫描技术和力学测试,对加入不同含量黄原胶(0%,0.5%,1.5%)加固的黏土在经历不同次数(0,1,4,8,12次)干湿循环作用下的力学性能和微观结构劣化机制进行了研究,得到结论:(1)黄原胶能够有效提高土体的抗压强度和耐干湿循环效果。随着黄原胶含量的增加,干湿循环作用后的强度损失逐渐减小,当循环次数从0次增加到4次时,对于加入黄原胶含量分别为0%,0.5%,1.5%的试样,抗压强度分别损失了42.75%,17.2%,14.04%。(2)加固土的抗压强度与干湿循环次数之间保持指数下降的关系,当循环次数达到4次后,随着循环次数的进一步增加,抗压强度和弹性模量均在较小的变化范围内波动。(3)随着干湿循环次数的增加,黄原胶加固土的孔隙率表现出先增加后减小的趋势,连通孔隙不断扩展,而孤立孔隙表现出先增加后减小的趋势。(4)随着试样的干燥,黄原胶在土颗粒间形成网状基质,提高土体的强度和耐干湿循环能力。

不同浓度对三赞胶溶液流变学特性的影响研究

制备质量浓度为0.1%~1.0%的三赞胶溶液,研究不同浓度对三赞胶溶液流变学特性的影响。通过稳态流动扫描、剪切应力扫描、温度扫描研究剪切速率、剪切应力及温度对黏度的影响,应变扫描、频率扫描、温度扫描研究应变、扫描频率及温度对弹性模量及粘性模量的影响,同时进一步考察了与结构特性相关的各因素如模量相交点、松驰时间、屈服应力等。结果表明:三赞胶溶液的流变学特性明显具有浓度依赖性,旋转测试与振荡测试所表现出来的流变学特性分别与浓度之间存在较高的相关性。溶液浓度改变时影响溶液流动时的应变及模量、溶液由粘性为主变为弹性为主时的频率与模量及松驰时间、由凝胶转换为溶胶时的温度与模量。

古籍文献老化因素分析检测及物理化学修补技术

针对中国古籍文献老化程度的分析研究,是对其进行科学评估和有效保护的一项重要基础工作。研究从2个方面探讨分析了古籍文献的老化因素,即纸张老化和字迹书写材料老化;并重点结合内因与外因分析影响古纸老化的原因,采用现代手段对古籍文献老化程度检测。并根据文物研究领域的发展现状和前沿动态,围绕纸张老化和字迹书写材料老化,介绍了光谱分析法和光学显微镜法2大类技术手段,用以测定古籍文献中纸张和墨迹的老化程度。解决和减缓古籍文献老化进程,重点梳理了纸质文物保护的无酸胶补修复及脱酸技术实现。

新型高效无氟泡沫灭火剂的制备及其性能表征

提出了一种由黄原胶、纳米二氧化硅颗粒和复配表面活性剂组成的新型环保型泡沫灭火剂,用于迅速扑灭易燃液体火灾。利用荧光分光光度计、液滴形状分析仪、润滑油抗泡沫特性测试仪以及双目透射偏光显微镜等试验研究了泡沫灭火剂的表面性能、聚集特性和发泡行为。结果表明,黄原胶以及二氧化硅纳米颗粒的加入使得10 min之内的泡沫稳定性保持在85%以上。通过泡沫性能测试,配比出最优异的泡沫性能,初始泡沫体积为905 mL,25%排水时间为300 s,10 min之内的排水量为105 mL,显著提升了泡沫的起泡性能和泡沫稳定性。随后使用该配方进行小型灭火试验,灭火时间为18 s,抗烧时间为650 s。

大豆分离蛋白与黄原胶复合对胡麻油乳液及其模板油凝胶物理性质的影响

为了研究大豆分离蛋白与黄原胶复合制备胡麻油基油凝胶的潜力,采用乳液模板法,在大豆分离蛋白(质量分数5%)与黄原胶(质量分数0.5%)体积比为1∶1、2∶1、3∶1、5∶1、10∶1的条件下制备了胡麻油基油凝胶,考察黄原胶添加比例对乳液稳定性、凝胶强度、油损失率和二级结构的影响。结果表明:随着黄原胶添加比例的增加,乳液的物理稳定性和黏弹性增大,乳液粒径明显减小,最小为(2.99+0.29)μm,乳化稳定性比对照组增加了1.5倍,表现出类似固体的性质。当大豆分离蛋白与黄原胶的体积比为1∶1时,油凝胶的油损失率比纯大豆分离蛋白油凝胶减少了26.87%。当大豆分离蛋白与黄原胶的体积比为3∶1时,凝胶强度G′>11000Pa,明显大于未添加黄原胶的油凝胶(1900Pa)。通过对油凝胶二级结构进行分析,发现聚合物链内的氢键是聚合物油凝胶形成的重要驱动力。本研究为食品用聚合物制备油凝胶提供了参考,并为其替代固体脂肪的潜在应用提供了理论基础。