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1.
The present prospective study examines proportions of maternal erythrocyte fatty acids across gestation and their association with cord erythrocyte fatty acids in normotensive control (NC) and preeclamptic pregnancies. We hypothesize that maternal fatty acid status in early pregnancy influences fetal fatty acid stores in preeclampsia. 137 NC women and 58 women with preeclampsia were included in this study. Maternal blood was collected at 3 time points during pregnancy (16–20th weeks, 26–30th weeks and at delivery). Cord blood was collected at delivery. Fatty acids were analyzed using gas chromatography. The proportions of maternal erythrocyte α‐linolenic acid, docosahexaenoic acid, nervonic acid, and monounsaturated fatty acids (MUFA) (p < 0.05 for all) were lower while total n‐6 fatty acids were higher (p < 0.05) at 16–20th weeks of gestation in preeclampsia as compared with NC. Cord 18:3n‐3, 22:6n‐3, 24:1n‐9, MUFA, and total n‐3 fatty acids (p < 0.05 for all) were also lower in preeclampsia as compared with NC. A positive association was observed between maternal erythrocyte 22:6n‐3 and 24:1n‐9 at 16–20th weeks with the same fatty acids in cord erythrocytes (p < 0.05 for both) in preeclampsia. Our study for the first time indicates alteration in maternal erythrocyte fatty acids at 16th weeks of gestation which is further reflected in cord erythrocytes at delivery in preeclampsia.  相似文献   

2.
Kinematic viscosity (µ) is an important physical property of fatty acid methyl esters (FAME) and biodiesel. In this work, the Martin's rule of free energy additivity is extended to cover the kinematic viscosity of saturated and unsaturated FAME commonly found in nature. The proposed model can also be extended to estimate kinematic viscosity of biodiesel. The kinematic viscosity of a FAME or a biodiesel can be easily estimated from its carbon number (z), number of double bonds (nd) at different temperatures (T) without a prior knowledge of the viscosity of individual FAME. Both zave and nd(ave) can be derived from its fatty acid composition. Thus, kinematic viscosity of biodiesel at temperatures between 20 and 100 °C and at atmospheric pressure can be estimated. The average absolute deviation (AAD) estimated at 20–100 °C for saturated, unsaturated FAME, biodiesels and biodiesel blends are 4.15, 3.25, 6.95 and 2.79 %, respectively. The biodiesels collected in this study (191 data points) have the zave and nd(ave) between 14.10 and 17.96 and 0.21–1.54, respectively. The standard deviation was 0.249. The proposed model would be good for estimation of viscosity of biodiesel containing normal fatty acids, generally found in biodiesel feed stocks.  相似文献   

3.
High catalytic activity was achieved in the deoxygenation of stearic acid in dodecane in a temperature range of 270–300 °C under 17 bar helium over palladium on nanocomposite carbon Sibunit. Besides n-heptadecane, which was obtained previously in this reaction with palladium on activated carbon, n-pentadecane was also formed in significant amounts.  相似文献   

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藻类花生四烯酸的提取工艺   总被引:1,自引:0,他引:1  
花生四烯酸作为一种重要的保健、营养品,越来越受到人们的重视。从鱼油、真菌丝、微藻中都可以提取花生四烯酸,但这些工艺都有着明显的缺点。设计了一种从藻类提取花生四烯酸的新工艺过程。  相似文献   

6.
以三乙醇胺、长链脂肪酸为原料,先经酯化、柱色谱提纯得到脂肪酸三乙醇胺单酯(FTME),再经磺化反应合成了4种脂肪酸三乙醇胺单酯琥珀酸酯磺酸盐(FTMS)两性表面活性剂,以月桂酸、棕榈酸、硬脂酸、油酸为脂肪酸合成的FTMS分别命名为FTMS-1、FTMS-2、FTMS-3、FTMS-4,通过FTIR与1HNMR表征了其结构,分别用碱性亚甲基蓝法和酸性溴酚蓝法验证了产物的离子性,并考察了FTMS结构中的烷基链长度及其不饱和度对表面张力、Krafft点、样品液粒径及粒径分布、乳化能力的影响。实验结果表明:产物显示出两性离子的特征;在系列FTMS中,随着脂肪链碳数增加,其Krafft点升高,平均粒径逐渐增大,但脂肪链中的不饱和双键有助于Krafft点的降低和粒径的减小。FTMS-1和FTMS-4具有优异的表面活性,其中FTMS-1的临界胶束质量浓度(CMC)为52.97mg/L,表面张力γCMC为36.1mN/m,其乳化能力(分离时间为148.8s)与AEO-9(分离时间为139.0s)相当且优于十二烷基磺酸钠(分离时间为113.8s)。  相似文献   

7.
We performed a cross-sectional study on 215 Japanese employees aged 20–68 years to investigate the association between NAFLD and serum phospholipid fatty acid composition. NAFLD was diagnosed by ultrasonography. The fatty acid composition between the control and NAFLD groups was compared, and the inverse probability of treatment weighting (IPTW) was performed to eliminate each confounding effect of sex, smoking status, BMI, insulin resistance, dietary cholesterol, and salt intake. A receiver operating characteristic (ROC) curve analysis was performed to evaluate the NAFLD prediction accuracy of fatty acids. Seventy-one subjects were diagnosed with NAFLD. Their serum phospholipid dihomo-γ-linolenic acid (DGLA) level was significantly higher after adjusting for each variable using IPTW. In the ROC analysis, the ratio of ARA to DGLA had an area under the curve (AUC) of 0.763. By combining the ratio of ARA to DGLA with the ratio of AST to ALT, AUC increased to 0.871. In conclusion, NAFLD subjects in a Japanese working population have higher serum phospholipid DGLA. Results of the IPTW and ROC analysis indicated that serum PL DGLA and the ratio of ARA to DGLA provide diagnosis information on the fatty liver that is different to AST and ALT and improve the accuracy of fatty liver prediction, owning potential value as serum biomarkers.  相似文献   

8.
Density is one of the most important physical properties of a chemical compound, affecting numerous applications. An application in the case of fatty acid esters (biodiesel) is that density is specified in some biodiesel standards. In the present work, the density of fatty acid methyl, ethyl, propyl, and butyl esters as well as triacylglycerols in the C8–C24 range was determined in the range of 15–40 °C with a densitometer utilizing the oscillating U-tube technique. Literature data on density are compiled and compared, showing that data for these compounds are incomplete with discrepancies existing in some cases. Besides known effects such as density decreasing with increasing chain length and increasing saturation, it is shown that trans fatty compounds exhibit lower density than cis fatty compounds. Density data for several saturated odd-numbered, C18, as well as C20 and C22 polyunsaturated fatty esters are reported for the first time. The density contribution of compounds with high melting points is predicted. An equation is given for the calculation of the density of mixtures.  相似文献   

9.
Growth hormone (GH) release is a process that is well regulated by several factors, including GH secretagogues. GH can mediate the regulation of the fatty acid level and composition. The aim of this study was to determine the effect of a synthetic GH secretagogue peptide (A233) on the growth and fatty acid composition in tilapia (Oreochromis niloticus). To address this objective, we administrated a diet supplemented with A233 to juvenile tilapia for 60 days. The group fed with a diet supplemented with 600 μg of A233 per kg of feed increased in weight (4.81 ± 0.09 g) and specific growth rate (2.49 ± 0.03%/day) compared to the control diet group (3.63 ± 0.08 g, 2.07 ± 0.04%/day; respectively) (p < 0.001). In the muscle, the total lipids for the control diet group were higher than that in the group fed with 600 μg of A233 per kg feed; however, no differences were detected in the liver. In both tissues, the patterns of fatty acid composition and content were generally similar, with some exceptions. Tilapia fed with 600 μg of A233 per kg of feed showed, in liver and muscle, a significantly higher composition and content of n‐3 polyunsaturated fatty acids (such as 20:5n‐3, 22:5n‐3, 22:6n‐3) and n‐3/n‐6 PUFA than animals fed with the control diet. To our knowledge, this is the first report on the the effects of natural or synthetic GH secretagogues (GHS) on fatty acid composition, implying an increase in the nutritional quality of the tilapia.  相似文献   

10.
Pure tetraesters of erythritol with C10, C12, C14, C16, C18 saturated, and C18:1 unsaturated (oleoyl) fatty acyl chains have been prepared for the first time and characterized using the acylating systems fatty acid/N,N′‐dicyclohexylcarbodiimide/4‐dimethylaminopyridine (DMAP), fatty acid anhydride/DMAP, fatty acyl chloride/pyridine, and fatty acyl chloride/boron trifluoride etherate. For the first three systems the yields were in the range of 80–90% while the fatty acyl chloride/pyridine system has the advantage of lower cost. The fatty acyl chloride/boron trifluoride etherate system gave lower (ca 70%) yields of the tetraesters. The tetraesters of erythritol may have applications analogues to those of triglycerides. In addition, new applications can be envisaged for these compounds, as a result of their differences in physical, chemical, and biochemical properties compared to triglycerides. Practical applications: The tetraesters of erythritol with saturated fatty acyl chains may have applications analogous to those of saturated triglycerides. However, tetraesters with unsaturated fatty acid chains may have greater prospects of having industrial uses after doing chemistry on the carbon–carbon double bonds.  相似文献   

11.
Murphy CC  Murphy EJ  Golovko MY 《Lipids》2008,43(5):391-400
Because X-linked adrenoleukodystrophy is treated using erucic acid (22:1n-9), we assessed its metabolism in rat liver and heart following infusion of [14-14C]22:1n-9 (170 Ci/kg) under steady-state-like conditions. In liver, 2.3-fold more tracer was taken up as compared to heart, accounted entirely by increased incorporation into the organic fraction (4.2-fold). The amount of tracer entering the aqueous fraction, which represents β-oxidation, was not different between groups; however a significantly elevated proportion of tracer was in the heart aqueous fraction. In both tissues, 76% of the radioactivity found in the organic fraction was esterified in neutral lipids, while only about 10% was found esterified into phospholipids. In liver, 56% of lipid radioactivity was found in cholesteryl esters, whereas in heart 64% was found in triacylglycerols. Because 22:1n-9 can be chain shortened, we assessed tracer metabolism using phenacyl fatty acid derivatives esterified from saponified esterified neutral lipid (triacylglycerol/cholesteryl ester) and phospholipid fractions. In heart esterified neutral lipids, 75% of tracer was recovered as 22:1n-9 and only 10% as oleic acid (18:1n-9), while in liver only 25% of the tracer was recovered as 22:1n-9, while 50% was found as stearic acid (18:0) and 10% as 18:1n-9. In liver and heart phospholipids, the tracer was distributed amongst the n-9 fatty acid family. Thus, 22:1n-9 under went tissue selective metabolism, with conversion to 18:0 the dominant pathway in the liver presumably for export in the neutral lipids, while in heart it was found primarily as 22:1n-9 in neutral lipids and used for β-oxidation.  相似文献   

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Transfer of fatty acids from mother to fetus during pregnancy is a requirement for optimal fetal growth. We report a longitudinal study of full maternal erythrocyte fatty acid profile assessed at each trimester of pregnancy [mean 12.5 (range 8–14), 26.1 (24–28) and 35.5 (33–38) weeks’ gestation] and in the post partum period [18.1 (12–26) weeks]. The study recruited healthy women (n = 47) from routine antenatal clinics at the Princess Royal Maternity Unit, Glasgow, Scotland. There were increases in 16:1n7 (22%, p = 0.0005), 24:1n9 (13%, p = 0.0032), 22:5n6 (25%, p = 0.0003), 18:3n3 (41%, p = 0.0007) and 22:6n3 (20%, p = 0.0005) concentrations during pregnancy. The greatest increases took place between gestations at sampling of 12.5 and 26.1 weeks. The change in 16:1n7 concentration between gestations at sampling of 12.5 and 35.3 weeks was negatively associated with maternal booking body mass index (r = −0.40, p = 0.006). The change in 22:6n3 concentration was correlated with the change in 24:1n9 (r = 0.70, p < 0.001). In samples taken four months post partum, 14:0 concentration was lower (29%, p = 0.0002) and 24:0 concentration (15%, p = 0.0009) and n6/n3 ratio (11%, p = 0.0019) were higher than at a gestation at sampling of 12.5 weeks. In conclusion, several fatty acids are specifically mobilised during pregnancy. The correlation between maternal 22:6n3 and 24:1n9 suggests that mobilisation of these fatty acids may be coordinated. The inverse relationship between 16:1n7 and maternal central obesity warrants further investigation.  相似文献   

15.
聚乙二醇型硼酸酯表面活性剂的合成与性能研究   总被引:1,自引:0,他引:1  
刘波  杜春林  洪哲 《辽宁化工》2011,40(1):22-24
以硼酸、甘油为原料,在N2保护下合成硼酸双甘油酯,然后在强酸性离子交换树脂催化下与聚乙二醇反应生成聚乙二醇硼酸双甘油酯,再分别与月桂酸、肉豆蔻酸、硬脂酸合成出3种聚乙二醇型硼酸酯表面活性剂。研究了聚乙二醇硼酸双甘油酯单月桂酸酯的合成工艺,得到了优化的工艺条件,测定产物的水解稳定性及其水溶液的表面张力。结果表明:硼酸双甘油酯聚乙二醇酯与月桂酸的摩尔比为1:1.0,反应温度240℃,反应时间6h,催化剂用量2.0%,月桂酸转化率为97.8%。该工艺具有酸转化率高,后处理工艺简单的优点,产物具有良好表面活性,其水解稳定性较传统的硼酸酯表面活性剂得到改善。  相似文献   

16.
Intrauterine growth restriction (IUGR) with rapid catch‐up growth leads to adult obesity and insulin resistance. We have previously shown that IUGR male rats demonstrated increased de novo fatty acid synthesis in the subcutaneous (SC) fat, but not the visceral fat, during the nursing period prior to the onset of obesity. Young IUGR females do not exhibit the same increase. We further hypothesized that in male IUGR offspring, de novo synthesis is a programmed intrinsic effect that persists to adulthood and does not suppress in response to a high fat diet. We measured fatty acid de novo synthesis in IUGR adult males (6 months) using deuterium‐enriched drinking water as a stable isotope tracer, then further studied the response after consumption of an isocaloric high fat diet. Baseline de novo synthesis in adult females was also studied at age 9 months. Males demonstrated increased baseline de novo synthesis in both SC fat and visceral fat. Correspondingly, SC and visceral fat protein expression of lipogenic enzymes acetyl‐coA carboxylase‐α (ACCα) and fatty acid synthase were upregulated. After the isocaloric high fat diet, de novo synthesis was suppressed such that no differences remained between the two groups, although, IUGR SC fat demonstrated persistently increased lipogenic protein expression. In contrast, de novo synthesis among adult females is not impacted in IUGR. In conclusion, enhancement of male IUGR SC fat de novo synthesis appears to be an early consequence of metabolic programming, whereas enhancement in visceral fat appears to be a later consequence.  相似文献   

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磷矿浮选中矿浆温度对增效作用的影响   总被引:7,自引:3,他引:4  
对磷灰石、石英混合矿和王集磷矿进行了浮选试验.结果表明:增效剂(Tween80、SDBS)在低温条件下对脂肪酸类捕收剂有增效作用,而高温时,会降低捕收剂的捕收性能。对其机理进行了探讨,为磷矿低温条件下有效浮选提出了一条新途径。  相似文献   

20.
脂肪酸甲酯制备表面活性剂的最新进展   总被引:3,自引:0,他引:3  
常致成 《化工科技》2000,8(1):60-64
综述了脂肪酸甲酯作为表面活性剂原料的重要性。介绍国内外脂肪酸甲酯系表面活性剂开发的最新进展;甲酯皂化制皂的新方法,MES生产新工艺,是乙氧基化制醚酯型n-SAA及甲酯催化氨化制备脂肪胺开发进展。  相似文献   

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