Relationship between platelet phospholipid FA and mean platelet volume in healthy men

Increased mean platelet volume (MPV) has been suggested as an independent risk factor for acute myocardial infarction and the increased reactivity of large platelets. The aim of this study was to investigate the correlation between platelet phospholipid (PL) PUFA composition and MPV in 139 free-living healthy men ages 20–55 yr (vegans, n=18; ovolacto vegetarians, n=43; modrerate meat-eaters, n=60; and high meateaters, n=18). Each subject completed a semiquantitative Food Frequency Questionnaire and gave a blood sample. Platelet PL FA composition and MPV were determined by standard methods. MPV was significantly greater in the vegans than in the ovolacto vegetarian, moderate, or high meat-eater groups (P<0.01). Both vegan and ovolacto vegetarian groups had significantly higher platelet PL 18∶2n−6 and 22∶4n−6, and lower 20∶5n−3 and 22∶6n−3 compared with the moderate and high meat-eater groups. The vegans demonstrated a significant reduction in 20∶4n−6 and 22∶5n−3 compared with the ovolacto vegetarian, high meat-eater, and moderate meat-eater groups. Bivariate analysis results showed that MPV was significanly positively correlated with platelet PL 18∶2n−6 (P=0.048) and negatively correlated with 20∶3n−6 (P=0.02), 20∶5n−3 (P=0.005), and 22∶5n−3 (P<0.0001), respectively. In a multiple linear regression analysis, after controlling for potential confounding factors such as dietary group, age exercise, body mass index, and dietary polyunsaturated and saturated fat, cholesterol, carbohydrate, and fiber intake, the MPV was still strongly negatively correlated with platelet PL 20∶3n−6 (P=0.003) and 22∶5n−3 (P=0.001). The present data suggest that 20∶5n−3 and 20∶3n−6 may play a role in the structural function of the platelet membrane.     

滤布材质及微观结构与透水性能的关系

机织滤布的透水性能会直接影响过滤设备的生产效率。为理清滤布材质、微观结构与过水通量之间的相互关系,定制一批控制变量的滤布用于实验。对不同材质的滤布进行了FTIR,动、静态接触角和表面能测定,从机理分析了材质影响过水通量的关键性指标。对滤布微观结构进行了SEM表征,并分析了编织方式、厚度、孔径对过水通量的影响,建立了滤布微观结构与过水通量的半经验模型。结果表明:材质亲水性大小顺序为聚丙烯>聚碳酸酯>聚酰胺,对应的过水通量分别为6.34、5.75、5.46 m/min,亲水性强的材质具有更大的过水通量;微观结构中,过水通量大小顺序为缎纹滤布>斜纹滤布>平纹滤布,孔径、厚度分别与过水通量呈正、负相关关系,拟合的微观结构与过水通量的半经验模型可以为机织滤布的选型提供理论参考。     

Relationship between mouse liver Δ9 desaturase activity and plasma lipids

This study was undertaken to investigate the total plasma fatty acid composition and the relationship between plasma triacylglycerol (TG) levels and liver Δ9 desaturase activity in mice fed n−3 and/or n−6 fatty acid or hydrogenated coconut oil (HCO) (maximum 25 mg/g) supplemented diets. Generally, plasma TG levels and Δ9 desaturase activity were inversely correlated with the ratio of the sum of long chain n−3 fatty acids to 18∶2n−6 and to the ratio of the sum of long chain n−3 fatty acids to 18∶n−3, but they were positively correlated with the ratio of products and substrates (18∶1/18∶0) of the enzyme in plasma total lipids. The n−3 fatty acid (mainly 20∶5n−3) enriched diet, when compared to the HCO diet at 21 d, caused a significant reduction in plasma TG levels but not in Δ9 desaturase activity. However, a marked reduction in plasma TG content (50–60%) and Δ9 desaturase activity (55–70%) was observed when both 20∶5n−3 and 18∶3n−6 were supplemented in the diet. The plasma TG levels and Δ9 desaturase activity rose again when the animals were fed the HCO diet or chow. The results suggest that low dose supplementation of a mixture of n−3 (mainly 20∶5n−3) and n−6 (18∶3n−6) fatty acids modified both plasma TG content and liver Δ9 desaturase activity, in parallel.     

Relationship between fluorine emission during firing of ceramic products and the firing temperature and composition of raw material

The fluorine content of clays from Lower Saxony and Bavaria was determined before and after firing. Although the mineral composition of the samples varied greatly, there was no evidence that any of the clay minerals contained significant amounts of fluorine. The amount of fluorine emitted within different temperature ranges during firing tests was determined for selected samples. Rates of temperature increase and heating times were also taken in consideration.A clear relationship between fluorine emission during firing and the Ca-content of the raw materials was demonstrated. Clays with low Ca-content started emitting fluorine at about 600°C; clays with a high Ca-content did not begin to release fluorine until 800°C. The addition of 10% CaCO₃ to a clay with a low Ca-content delayed the emission of fluorine until the higher temperature was reached.Because of the very low fluorine concentration in the raw materials, X-ray analysis could not be used to determine the compound in which calcium binds fluorine in the firing products. Tests with synthetic mixtures (NaF-CaCO₃ and NaF-CaCO₃-SiO₂) led to the conclusion that CaF₂ and various calciumfluorosilicates were involved.     

Species variation in the atherogenic profile of monkeys: Relationship between dietary fats,lipoproteins, and platelet aggregation

Because lipoproteins and platelet aggregation have been implicated in atherogenesis, relative differences in the response of these variables to dietary fat saturation were compared in three species of monkeys differing in their susceptibility to atherosclerosis (cebus, rhesus, and squirrel monkeys). Both long-term (8–12 years) and short-term (8 weeks) responses to diets containing 31% fat calories were examined in the same monkeys. As expected, long-term feeding of coconut oil by comparison to corn oil produced significantly higher plasma concentrations of total cholesterol, LDL cholesterol, apoB, and triglycerides, as well as higher ratios of LDL/HDL cholesterol and apo B/apo A-I. These responses were characteristic of all species with cebus being most responsive and rhesus the least. The shortterm plasma cholesterol response to animal fats (butter, lard, beef tallow) was significantly less than that to coconut oil. When fish oil was substituted for two-thirds of either corn oil or coconut oil, exceptional decreases occurred in plasma cholesterol and triglycerides, as well as in HDL cholesterol and apo A-I concentrations despite the fact that the fish oil diets contained more saturated fat and less polyenes than the corn oil diet. Platelet aggregation tended to increase with saturated fat consumption and greatly decreased with fish oil intake in all monkeys, although cebus monkeys were ten-fold more resistant to platelet aggregation than the other two species. The molecular species of platelet phosphatidylcholine (PC) varied with both the dietary fat fed and species of monkey. An inverse correlation (r=−0.60; p<0.001) was found between changes in one such PC molecular species (18∶0−20∶4) induced by diet and the platelet aggregation threshold. These results demonstrate that the lipemic and platelet responses to dietary saturated fat depend upon both the type of fat (i.e., the specific combination of dietary fatty acids, including the chain length of saturated fatty acids and the degree of polyunsaturation) and the species of monkey (genetic component) in which the response is elicited.     

Relationship between lipids in plasma and skin secretions of neonatal calf with particular reference to linoleic acid

A study has been made on the lipid composition of the skin secretions and plasma of the neonatal calf. A significant proportion of the skin surface lipids was comprised of triglycerides. Saturated fatty acids comprised the major proportion of the fatty acids of the skin surface triglycerides at birth. Immediately after birth, the pooportion of the saturated fatty acids decreased, and there was a concomittant increase in the proportion of 18∶1. Some 3–4 weeks after birth, the proportion of 18∶2 Δcis-9, cis-12 in the skin surface triglycerides increased to ca. 14%, and there was a decrease in the proportion of 18∶1. The 18∶2 was shown to be confined almost entirely to the 2 position of the triglycerides. During the first 5 weeks after birth, the concentrations of the cholesteryl esters and phospholipids in the plasma increased markedly and were accompanied by a rapid increase in the proportion of 18∶2 within these 2 fractions. The results are discussed in relation to the known role of 18∶2 in the metabolism of biological systems.     

溶解度与多晶型浅谈

许多热力学和动力学因素都对晶体的晶型控制有影响,文章中主要介绍溶解度与晶体多晶型之间的内在联系.首先,介绍了晶体学的一些基本理论,其次,介绍溶解度曲线在判定多晶型稳定性中的应用;溶解度曲线对多晶型成核速率的影响,最后,介绍溶解度曲线在溶剂介导晶型转化机制中的贡献.     

Relationship between perfumes and colors

Les sens sont des espèces d'instruments dont il faut apprendre à se servir (Voltaire—Traité de Mètaphysique). When a stimulus is perceived by the perceptive system coupled with another sense, one is in the presence of a case of synesthesis. But pseudocases of synesthesis may exist, where it is only psychologic or affective relations which provoke or facilitate such exchanges. These have been studied by the author according to relations between vision of colors and olfactive or gustative senses.     

人参皂苷Rg1诱导人红白血病K562细胞株衰老与p16-Rb信号通路的相关性

目的探讨人参皂苷Rg1(以下简称Rg1)诱导人红白血病K562细胞株衰老与p16-Rb信号通路的相关性。方法以不同浓度的Rg1(0、5、10、20、40和80μmol/L)作用于K562细胞不同时间(24、48、72 h),MTT法筛选Rg1抑制K562细胞增殖的最佳作用浓度及作用时间,以该浓度干预K562细胞不同时间,流式细胞术检测细胞的细胞周期;以最佳浓度Rg1干预K562细胞最佳时间,集落培养法检测细胞集落形成能力;衰老相关-β-半乳糖苷酶(SA-β-Gal)染色检测阳性细胞百分率;透射电镜观察细胞的超微结构;Southern blot检测细胞的端粒长度;Western blot检测细胞中P16和RB蛋白的表达。结果 Rg1在体外可明显抑制K562细胞增殖,其最佳作用浓度及作用时间分别为20μmol/L和48 h;经20μmol/L Rg1诱导48 h的K562细胞与常规培养对照组相比,细胞出现G2/M期阻滞(P<0.05),集落形成能力明显减弱(P<0.05),SA-β-Gal染色阳性率增加(P<0.01),细胞体积增大,且溶酶体,线粒体体积增大,数目增多,端粒缩短加速(P<0.05),P16和RB蛋白表达上调(P<0.05)。结论 Rg1能诱导人红白血病K562细胞株衰老,可能与Rg1激活了p16-Rb信号通路有关。     

Relationship between the material properties and fatigue crack‐growth characteristics of natural rubber filled with different carbon blacks

An investigation of the influence of different types of carbon black on fatigue crack‐growth behavior was undertaken. Fatigue tests were carried out on edge‐notched specimens under cyclic tension loading. A power‐law dependency between the crack‐growth rate and tearing energy was obtained. Natural rubber (NR) filled with N330 (the mean diameter is 30 nm) carbon black possessed the lowest values of exponent b and constant B (the two crack growth parameters determined from cyclic crack growth testing), which denoted the strongest resistance to crack growth at a given tearing energy. Strain‐induced crystallization was investigated by the modified Mooney–Rivlin equation and showed the earliest appearance and strongest ability of the crystallization of the NR/N330 composite at the largest amount of bound rubber. The study on the viscoelastic properties by dynamic mechanical analysis confirmed that the NR/N330 composite had the largest viscoelastic contribution, which was attributed to the viscoelastic dissipation in the viscoelastic region in front of the crack tip. All of these results confirm the best crack‐propagation resistance of NR filled with N330. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Relationship between sintering methods and physical properties of the low positive thermal expansion material Al2W3O12

Ceramic materials from the A₂M₃O₁₂ family with near-zero thermal expansion are good candidates for applications requiring high thermal shock resistance. Considering their inherently low thermal conductivity, the bulk forms of A₂M₃O₁₂ have to present Young's moduli and mechanical strength close to 100 GPa and 100 MPa, respectively, in order to compete with the state-of-the-art materials used to avoid thermal shock. The relationship between sintering, microstructure, and physical properties within the A₂M₃O₁₂ family is generally unknown while the preparation of bulks with high mechanical resistance remains a great challenge. Bulk samples of dense Al₂W₃O₁₂ (96%TD) have been obtained by pressureless three-stage sintering (TSS) and spark plasma sintering (SPS). The Young's moduli and hardness of samples prepared by SPS were 50% higher than that measured for TSS samples and more than 100% in comparison to the Al₂W₃O₁₂ bulk (91%TD). UV-Vis spectroscopy confirmed that A₂M₃O₁₂ phases are wide band-gap semiconductors (3.11 eV). When prepared by SPS, black Al₂W₃O₁₂ absorbed light within the visible spectrum due to the introduction of donor sites within the band-gap. No enhancement of the mechanism causing negative thermal expansion was observed for black Al₂W₃O₁₂. The mechanical properties achieved were significantly improved over those previously reported in literature for Al₂W₃O₁₂.     

放电等离子烧结合成单相MgAlON材料

以氮化铝、富铝镁铝尖晶石和氧化铝为原料 ,用放电等离子烧结 (SPS)技术合成了单相MgAlON,研究了其显微结构 ,并与用传统的无压烧结 (PLS)技术制备的单相MgAlON材料在显微结构和断裂行为上做了比较。结果表明 :用SPS法在 170 0℃保温 1min的条件下合成出的单相MgAlON材料 ,显微结构比用PLS法合成的更加均匀致密 ,且晶粒细小 ;前者的断裂模式主要是穿晶断裂 ,后者的断裂模式则主要是沿晶断裂。     

有机化学与药学的关系

对中药、西药的关系及有机化学在中药、西药发展中的应用等各方面进行了综述,阐述了有机化学在西药合成、西药代谢和中药的分离提纯、中药成分结构鉴定中都有重要的应用,并推动了中西药学的发展,使中西药学的体系更加完善。随着科学技术的迅速发展,各学科之间互相交融,有机化学在中西药物研发中发挥越来越重要的作用,对药学行业的发展与进步起着巨大的推动作用。     

焦炭反应性与煤岩亚组分的关系研究

为研究原料煤性质对焦炭反应性的影响,从煤岩亚组成的角度分析了均质镜质体、基质镜质体、丝质体及粗粒体与焦炭反应性的关系,研究了其对焦炭反应性产生的综合影响。结果表明,均质镜质体、基质镜质体、丝质体及粗粒体含量分别为37%~46%、19%~30%、11%~13%、3%~6%时,焦炭反应性最小;均质镜质体和基质镜质体有利于形成反应性较低的焦炭结构;粗粒体和丝质体炼焦过程中未发生软化熔融,不利于形成反应性较低的焦炭结构;在相同变质程度下,基质镜质体对形成反应性较低焦炭结构所起的作用大于均质镜质体,粗粒体对形成反应性较低焦炭结构所产生的不利影响大于丝质体。     

是效益最大化,还是市场最大化——关于市场与效益关系的思索

在社会主义市场经济中，企业要通过市场才能获得效益，只有将经济效益和市场有机地结合起来，通过追求市场最大化，才能达到效益最大化。提高质量，既有利于效益，又有利于市场，但过高的质量对效益不利。价格与效益成正比，与市场成反比。建品牌、创名牌、开展质量认证活动和薄利多销，是提高效益与扩大市场的有效途径。     

Relationship between Fractal Geometry and Fractography

Fractal geometry has been used to describe irregular fracture surfaces in a quantitative way. The fractal dimensional increment has been related to the fracture toughness of the material through the elastic modulus and a characteristic structure parameter, a ₀. The study of fractography has shown the relationship between the flaw/mirror size ratio and the fracture toughness. An experimental observation has shown that the fracture toughness is related to the elastic modulus through another structure parameter, b ₀. Combining all of these relationships leads to the conclusion that the fractal dimensional increment, D ^*, is directly related to the flaw/mirror size ratio. Experimental measurements of the fractal dimension and the flaw/mirror size ratio on glasses, a glass-ceramic, polycrystalline ceramics, and a single crystal all agree with the prediction. The implication of this finding is that there is a linear scaling law in operation at fracture between the energy of crack initiation and of microbranching and is reflected in the features on the fracture surface.     

Mo与材料组织的关系

测定了一种不合Mo和一种加Mo管道用钢的动态连续冷却转变曲线,通过光学显微镜、扫描电镜和透射电镜观察两钢不同条件下的显微组织的形貌特征.结果表明,随着冷速的增加,两钢的组织由多边形铁素体、准多边形铁素体转变为针状铁素体,同时晶粒得到细化;试验钢组织在低冷速时变化较明显,当冷速大于5℃/s时组织类型变化不明显,此时主要是组织均匀性及M-A岛发生变化,随冷速增加M-A岛更细小、弥散;Mo使CCT曲线中针状铁素体转变曲线右移,促进针状铁素体组织形成.     

Relationship between adhesion and friction forces

The Surface Forces Apparatus technique was used to measure the normal (perpendicular) and lateral forces between variously prepared surfaces under both dry and lubricated conditions. 'Normal' forces include the force vs distance functions, F(D), for surfaces separated by thin liquid films as well as the adhesion forces and energies, γ, for two surfaces in adhesional contact. 'Lateral' forces include the static and kinetic friction forces F of the surfaces as they slide past each other at a given separation, D. The results show that very thin liquid films confined between two solid surfaces can sustain both normal and shear forces or stresses. The results further indicate that the normal force, F(D) or γ, may be directly related to the static friction force, F_s, and simple equations are proposed that relate these forces (by 'static' friction force is meant the lateral force that must be applied to initiate motion, but not necessarily to maintain this motion). In contrast, the kinetic friction force, F_k, which is the force that must be continually applied to maintain motion at a given velocity, was found to be related, not to the equilibrium or reversible interaction but to the dissipative or irreversible part of the adhesion or interaction energy during a loading-unloading cycle. There is a high degree of correlation in the way that normal forces and friction forces are affected by changes in applied load or pressure, sliding velocity, loading-unloading rates and temperature. These systematic correlations can be conveniently represented by non-equilibrium 'adhesion' and 'friction' phase diagrams.     

耐火材料与洁净钢的关系

从化学热力学分析讨论了耐火氧化物及复合氧化物与钢液中平衡氧含量的关系 ,钢液中氧含量与氧势的关系 ,耐火氧化物与钢中硫含量 ,耐火氧化物及结合剂与钢中磷含量 ,耐火材料中残余水分及有机结合剂与钢中氢含量的关系 ,以及炼超低碳钢时的碳污染等问题。