老年女性红细胞比积正常参考值的回归分析

为制定中国老年女性红细胞比积正常参考值的统一标准提供科学依据,收集了中国12 395例健康老年女性红细胞比积正常参考值,研究了其与地理因素的关系.发现海拔高度是影响老年女性红细胞比积正常参考值最主要的因素.随着海拔高度的逐渐增大,老年女性红细胞比积正常参考值也在逐渐增大,相关性很显著(r=0.876).用多项式回归分析的方法推导出回归方程为Y=54.4 0.001 00X1-0.286X3-0.624X4 0.004 00X5 1.21×10-7X21 0.002 00X23 0.018 0X24-1.91×10-6X25±3.9,由此模型如果知道了中国某地的地理因素,就可以用回归方程估算这个地区的老年女性红细胞比积正常参考值.依据老年女性红细胞比积正常参考值与地理因素的依赖关系把中国分为青藏区,西南区,西北区,东南区,华北区,东北区等6个区.     

老年前期男性红细胞沉降率参考值的FLR分析

为制定老年前期男性红细胞沉降率正常参考值的统一标准提供科学依据.收集了中国281个单位用温氏法(Wintrobe)测定的23 517例健康老年前期男性红细胞沉降率正常参考值,运用相关分析和模糊线性回归分析的方法,研究了其与地理因素的关系.发现海拔高度是影响老年前期男性红细胞沉降率正常参考值最主要的因素,用模糊线性回归分析的方法推导出一个模糊回归方程:(?)=(-0.001 891 53,0)x_1 (0.001 867 936,0.001 219 046)x_2 (0.117 074 7,0)x_3 (0.147 477 6,0)x_4 (-0.000 176 361,0)x_5.依据老年前期男性红细胞沉降率正常参考值与地理因素的依赖关系把中国分为青藏区、西南区、西北区、东南区、华北区和东北区.     

6×(26+20+1×36SW)+FC-72钢丝绳生产

6× ( 2 6 + 2 0 + 1× 36SW ) +FC - 72是一种新颖的点线复合结构钢丝绳 ,与 6× 6 1结构钢丝绳相比 ,股中钢丝根数从 6 1增加到 82 ,金属密度系数增加了 2 %～ 3% ,主承载钢丝直径从 2 .6mm减小到 2 .4mm ;该产品的成功开发 ,丰富了我国钢丝绳设计理念 ,摸索出在西鲁、西鲁 -瓦林吞式线接触钢丝绳基础上再多次包捻钢丝 ,生产钢丝绳主股的新方法     

酿酒红曲米特征与产品酸度的相关性分析

以25份福建省酿酒红曲米为对象,采用多元统计方法,分析红曲pH值、干燥失重、容重、淀粉、蛋白质、总氨基酸、液化力、糖化力、发酵力、产酒力等特性指标与酿造产品总酸的相关性,并建立回归模型。结果表明:糖化力、液化力和发酵力的变异系数最大;红曲pH值、发酵力与产品酸度的相关性及偏相关性均达显著或极显著水平;产品酸度(y)与红曲pH(x1)、容重(x2)、淀粉(x3)、蛋白质(x4)、液化力(x5)、发酵力(x6)及产酒力(x7)的回归方程为:y=-206.6614+40.55114x1+8. 9631x6+1. 16790x7+0. 1086x1x5-0. 9471x1x6-0. 2151x1x7-0. 0002x2x3+0. 0002x2x5+0.0244x3x5-0.0768x3x6+0.0264x4x5-0.1749x4x6+0.0233x5x6-0.0101x5x7(R=0.9894,P=0.0001),其中,红曲pH值、发酵力、产酒力是重要的影响因子,进一步建立的单因子回归方程均达显著及极显著水平。     

早期断奶仔猪日粮蛋氨酸和苏氨酸水平的研究

试验采用早期断奶仔猪 (2 6± 1日龄 ,6 .6 8± 0 .0 4kg体重 ) 72头 ,按 2× 3因素水平设计 ,即 2个蛋氨酸水平(0 .2 9% ,0 .39% )和 3个苏氨酸水平 (0 .6 0 % ,0 .6 8%和 0 .76 % )分为 6种日粮处理。基础日粮为玉米 -小麦 -豆粕-花生粕型日粮 ,试验期为 2 2d ,测定仔猪断奶后 0～ 10d ,11～ 2 2d及全期生长性能。结果表明 ,早期断奶仔猪断奶后营养应进一步分阶段供给 ,断奶早期 (2 6～ 36日龄 ,6 .6 8～ 8.1kg体重 )日粮中适宜的蛋氨酸与苏氨酸水平应为0 .39% (Met+Cys 0 .71% )及 0 .6 8% ,断奶后期 (37～ 48日龄 ,8.31～ 14.0kg体重 )为 0 .2 9% (Met +Cys 0 .6 1% )及0 .6 8%。     

6×17S+FC-6.3mm镀锌电梯钢丝绳的研制

1　技术要求与特点6× 17S +FC - 6 .3mm镀锌电梯钢丝绳的技术要求和特点如下。(1)结构新颖。该电梯钢丝绳股数为 6股、西鲁式 ,股的结构为 1+8+8。(2 )绳径为非标。电梯绳的绳径为 6 .3mm。(3)表面镀锌。锌层质量按航空钢丝绳YB/T5 197— 93标准B级 (与客户协商确定 )。(4 )强度高。钢丝绳抗拉强度σb≥ 196 0MPa ,破断拉力≥ 2 6 .7kN。(5 )钢丝绳直径允许偏差。公称直径的 0～ +6 %。(6 )钢丝绳不圆度≤公称直径的 5 %。2　制绳用钢丝的生产2 .1　钢丝直径的确定(1)股径计算。 6× 17S +FC - 6 .3mm电梯钢丝绳直径D =6 .3mm ,根据…     

牛奶中青霉素含量的快速检测

在1 ml待检牛奶中加入3滴Benedict试剂,煮沸5 min.根据试样中颜色变化,判断牛奶中青霉素含量.青霉素含量为(80～100)×10-6显红色,(50～70)×10-6显红黄色,(30～40)×10-6显橘黄色,(10～20)×10-6显浅橘黄色,(5～9)×10-6显正黄色,(0～4)×10-6显黄色.     

食品中Nisin抗菌效果影响因素的研究

研究了木瓜蛋白酶的添加量、Nisin的添加量及 p H对 Nisin抗菌效果的影响。得出了处理后细菌数和各因素间的二次回归方程 :y=30 .44- 1 8.74x1+ 1 6.52 x- 4.36x3- 1 8.2 x1x2 + 1 8.1 0 x      

基于指纹图谱相似度的米糠油掺伪检测方法研究

为快速准确对掺伪米糠油进行定量检测,将棕榈油、棉籽油、菜籽油、大豆油掺入纯米糠油,气相色谱法测定C10∶0、C14∶0、C16∶0、C16∶1、C18∶0、C18∶0、C18∶1、C18∶1、C18∶2、C18∶3、C20∶0、C20∶1、C22∶0、C22∶1的含量,利用向量夹角余弦法计算纯米糠油与掺伪米糠油的相似度,建立了掺伪量与相似度的线性模型.米糠油掺混棕榈油,计算模型为y =5.802 3x3-17.469x2-0.269 2x +99.99(R2 =0.999 6).米糠油掺混菜籽油,计算模型为y=-23.62x3-8.380 6x2-6.138 3x+ 100.12(R2=0.999 4).米糠油掺混棉籽油,计算模型为y=-240.52x5+ 677.8x4-697.92x3+ 312.09x2-66.998x+ 99.97(R2=0.999 3).米糠油掺混大豆油,计算模型为y=12.33x3-26.047x2-2.6855x+100.05(R2=0.999 1).     

啤酒中草酸含量的测定

建立了三氯化钛光度法测定啤酒中草酸含量的方法,测定条件为pH1．5-1．7,检测光波长为400nm;测量范围0．3×10-3-4×10-3mol/L,检出下限0．3×10-3mol／L。结果表明,测定平均回收率为99．6％;而且具有一定的重现性。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Detection of adulteration of locust bean gum with guar gum by capillary electrophoresis and polarized light microscopy

Capillary electrophoresis (CE) and polarized light microscopy (PLM) were utilized in the detection of the adulteration of locust bean gum with guar gum. For CE analyses, standards of locust bean and guar gums were extracted with 30% CH₃CN, removing the residual proteins from the gum matrix. A 8.75 mM NaH₂PO₄-20.6 mM Na₂B₄O₇ buffer, pH 9, was used to separate these proteins and to identify marker proteins that were present in the guar gum. These markers did not co-migrate with components in the extracts of mechanically processed locust bean gum, and are used as indicators of adulteration. Using PLM with toluidine blue and iodine staining techniques, unadulterated locust bean gum samples were distinguished from mixed samples through the differential staining of components in locust bean versus guar and tara gums. These experiments in the use of CE and PLM provide orthogonal and complementary methods for the verification of 'true' positives and the elimination of 'false' positives.