壳聚糖固定化月桂酸及其吸附LDL性能研究

以月桂酸为原料,将其固定到活化壳聚糖上,制备一种低密度脂蛋白胆固醇(LDL-C)选择性吸附剂。考察了吸附时间、吸附剂用量对血浆LDL-C吸附效果的影响。体外间歇吸附结果表明,LDL-C的吸附率达到58.5%,对血浆总胆固醇(TC)吸附率达到35.1%,而对高密度脂蛋白胆固醇(HDL-C)的吸附率为11.4%,具有良好的选择吸附低密度脂蛋白胆固醇性能。     

大孔吸附树脂磺化改性及其性能研究

采用适宜孔径参数的大孔吸附树脂经90%浓硫酸在一定条件下磺化改性作为血脂吸附剂,并评价吸附剂对低密度脂蛋白、胆固醇等血脂物质的吸附效果。通过测定吸附剂对血细胞的作用、溶血率、凝血酶原时间和体外血栓试验以评价吸附剂的血液相容性。结果显示血脂吸附剂对低密度脂蛋白、胆固醇有一定的吸附作用,但对高密度脂蛋白吸附较少。血脂吸附剂对血细胞粘附较少,溶血率为1.31%符合要求。凝血酶原时间和体外血栓试验结果显示血脂吸附剂与上市的血液灌流吸附剂无显著差异,还有血脂吸附剂的微粒脱落数满足标准要求表现出一定的物理强度。因此表明适宜孔径参数的大孔吸附树脂经浓硫酸磺化改性作为血脂吸附剂具有一定的可行性。     

改性龙眼壳对废水中六价铬离子的吸附研究

采用硫酸溶液对龙眼壳进行改性制备吸附剂,研究吸附剂粒径、废水浓度、吸附时间和温度等因素对吸附率的影响。结果表明,改性吸附剂吸附Cr(Vl)的最佳pH为2.0、离子浓度为30 mg/L、吸附时间为100 min时,吸附率可达到99%左右。改性吸附剂对Cr(Vl)的吸附符合准二级动力学方程,经过5级静态吸附后,吸附率仍可以达到83.39%。用HCl溶液(1+5)对吸附后的改性龙眼壳可解吸再生,改性龙眼壳可作为含铬废水的处理材料。     

磺化太西煤吸附剂的制备及吸附性能研究

以浓硫酸为磺化剂对无烟太西煤进行改性,通过水热反应得到磺化太西煤吸附剂。由FTIR、SEM、XRD测试结果确认该磺化太西煤具有丰富的官能团和多孔结构。采用静态吸附法测定该磺化煤作为吸附剂对Zn~(2+)、Fe~(3+)及苯酚的吸附率,研究了吸附时间、温度、pH值、模拟废水初始浓度对吸附率的影响,并探讨了吸附机理。结果表明,在酸性条件下,磺化太西煤不仅具有传统吸附剂的孔道吸附与离子交换作用,而且其官能团特有的金属络合作用、氢键作用促使该吸附剂对废水中Zn~(2+)、Fe~(3+)和苯酚的吸附率均达到95%以上。     

聚吡咯/凹凸棒对罗丹明B染料废水脱色性能研究

以三氯化铁(Fe Cl3)为氧化剂,十二烷基磺酸钠为掺杂剂,采用原位聚合法制备聚吡咯(PPy)/凹凸棒(ATP)纳米复合材料。以罗丹明B(Rh B)水溶液为模拟染料废水,研究了该复合材料的吸附性能。结果表明:该吸附剂具有很高的吸附速率,当pH值=6、吸附剂用量为5g/L、吸附时间t=10min时染料的脱色率达到94.7%。     

含钛高炉渣制备复合吸附剂及其铬吸附性能

Cr(Ⅵ)是一种有害污染物,既污染水环境,也会对人体造成伤害。本文以工业固废含钛高炉渣为原料,通过酸浸得到浸出渣基体,经壳聚糖改性,制备一种新型GLZ-jcz/CS复合吸附剂,用来去除废水中的Cr(Ⅵ)。研究了吸附温度、废水pH、吸附剂量、Cr(Ⅵ)初始浓度、吸附时间对Cr(Ⅵ)吸附性能的影响。以Cr(Ⅵ)吸附率为评价指标,确定最优实验条件,并研究了GLZ-jcz/CS复合吸附剂的再生性能。采用扫描电子显微镜、傅里叶红外变换光谱仪、X射线光电子能谱仪、BET比表面积测试仪对GLZ-jcz/CS复合吸附剂进行表征,结合吸附动力学模型和吸附等温线模型分析,确定吸附机理。实验结果表明：当吸附温度为70℃、废水pH=4、吸附剂用量为0.13g、Cr(Ⅵ)初始浓度为50mg/L、吸附时间为2h时,吸附率达到99.8%,吸附容量可以达到67mg/g,GLZ-jcz/CS复合吸附剂经过6次洗脱,吸附率仍可达到96%以上,吸附模型符合拟二级动力学模型和Langmuir吸附等温模型。     

酵母菌对电镀废水中Cr(Ⅵ)的去除研究

研究了pH、时间、温度、干扰离子等对酵母菌吸附电镀废水中Cr(Ⅵ)的影响,并对其等温吸附过程及动力学和热力学参数进行了分析和探讨。结果表明,以灭活酵母菌作为生物吸附剂时,溶液中干扰离子的存在会降低吸附剂的吸附效率,一定范围内温度越高吸附效果越好,吸附时间为960 min时吸附达到平衡,吸附效果最佳的溶液pH值为2,吸附剂的吸附过程遵循准二级动力学模型。对电镀废水进行Cr(Ⅵ)吸附试验,发现Cr(Ⅵ)的吸附率可以达到71.71%~76.86%。     

磺化太西煤吸附剂的制备及吸附性能研究

以浓硫酸为磺化剂对无烟太西煤进行改性,通过水热反应得到磺化太西煤吸附剂。由FTIR、SEM、XRD测试结果确认该磺化太西煤具有丰富的官能团和多孔结构。采用静态吸附法测定该磺化煤作为吸附剂对Zn⁽²⁺⁾、Fe(2+)、Fe⁽³⁺⁾及苯酚的吸附率,研究了吸附时间、温度、pH值、模拟废水初始浓度对吸附率的影响,并探讨了吸附机理。结果表明,在酸性条件下,磺化太西煤不仅具有传统吸附剂的孔道吸附与离子交换作用,而且其官能团特有的金属络合作用、氢键作用促使该吸附剂对废水中Zn(3+)及苯酚的吸附率,研究了吸附时间、温度、pH值、模拟废水初始浓度对吸附率的影响,并探讨了吸附机理。结果表明,在酸性条件下,磺化太西煤不仅具有传统吸附剂的孔道吸附与离子交换作用,而且其官能团特有的金属络合作用、氢键作用促使该吸附剂对废水中Zn⁽²⁺⁾、Fe(2+)、Fe⁽³⁺⁾和苯酚的吸附率均达到95%以上。     

生物吸附剂对实验室废水中Cr(Ⅵ)的吸附条件研究

以生物吸附剂花生壳和甘蔗渣作为吸附剂,讨论了原料粒径大小、吸附时间、温度、初始溶液p H值、加入量、振荡速率对吸附效率的影响。结果表明最佳吸附条件为:甘蔗渣吸附剂过80目筛,投加量为0. 8 g,吸附溶液初始p H为2. 0,35℃时以200 rpm的速率振荡300 min,对实验室废水中Cr(Ⅵ)的吸附率可达95. 10%;花生壳吸附剂过120目筛,投加量1. 0 g,35℃时以150 rpm的速率振荡180 min,对实验室废水中Cr(Ⅵ)的吸附去除率达到97. 52%。     

TiO_2-Fe_3O_4-ATP吸附剂对P(Ⅴ)的吸附和脱附

通过凹凸棒黏土负载TiO_2-Fe_3O_4制备了TiO_2-Fe_3O_4-ATP吸附剂,进行了P(Ⅴ)的静态吸附和脱附实验,对其动力学和热力学参数进行了研究。通过SEM对凹凸棒黏土负载纳米TiO_2-Fe_3O_4前后结构进行了表征,考察了物料配比及吸附时间、pH值、温度、投加量和初始浓度对P(Ⅴ)吸附率的影响。结果表明,3/4负载TiO_2-Fe_3O_4-ATP吸附剂对P(Ⅴ)有良好的吸附作用,当吸附剂质量为0.6 g,P(Ⅴ)离子初始浓度0.6 mg/L时,pH为8左右,温度20℃,吸附剂对P(Ⅴ)的吸附率为92.9%。吸附过程为准二级动力学,吸附类型与Freundlich吸附模型一致。TiO_2-Fe_3O_4-ATP吸附剂在循环使用4次后,吸附率仍能达到77%以上。     

Low-Density Lipoprotein Cholesterol/High-Density Lipoprotein Cholesterol Ratio and Carotid Intima-Media Thickness: A Cohort Study in China

Low-density lipoprotein cholesterol to high-density lipoprotein cholesterol (LDL-C/HDL-C) ratio may carry additional information and has been suggested as a better predictor for atherosclerosis progression and cardiovascular disease (CVD) than LDL-C and HDL-C alone. Therefore, we aim to explore the association between LDL-C/HDL-C ratio and high carotid intima-media thickness (CIMT) risk in a large Cohort in Beijing, China. This cohort study included 13,612 adults without high CIMT at first entry and who attended the baseline examination and at least one follow-up annual examination between 2009 and 2016. We used multivariable Cox regression to estimate hazard ratios (HR) with their 95% confidence intervals (CI) for the association between LDL-C/HDL-C ratio and risk of high CIMT. During 37,912 person-years of follow-up, 1996 (1268 men and 728 women) developed high CIMT. Compared with the first quartile of LDL-C/HDL-C ratio, the risk of high CIMT was significantly increased for the fourth quartile of LDL-C/HDL-C ratio (HR = 1.51, 95% CI: 1.29–1.78). We observed a significant association between LDL-C/HDL-C ratio and high CIMT risk comparing LDL-C/HDL-C ratio >2.78 with LDL-C/HDL-C ratio ≤2.78 and significant dose–response relationship between LDL-C/HDL-C ratio and risk of high CIMT. The restricted cubic spline showed a significant nonlinear association between LDL-C/HDL-C ratio and the risk of high CIMT (p_{non-linearity} = 0.009). We identify a significant association between LDL-C/HDL-C ratio and the risk of high CIMT in the Chinese Cohort study. Future studies are needed to evaluate the effectiveness of reducing LDL-C/HDL-C ratio treatment on the development of high CIMT.     

Interaction between dietary proteins and lipids in the regulation of serum and liver lipids in the rabbit. Effect of fish protein

Purified diets varying in dietary protein, namely casein (CA), soy protein (SP), fish protein (FP), and lipid origin (corn oil (CN), coconut oil (CO)) were fed to rabbits to evaluate the effects of protein and fat source, as well as protein-lipid interactions, on serum total, lipoprotein and hepatic lipid levels. Dietary proteins and lipids exerted a separate effect on serum total cholesterol (C), very low-density lipoprotein cholesterol (VLDL-C), and low-density lipoprotein cholesterol to high density lipoprotein cholesterol (LDL-C/HDL-C) ratio. Hence, CA increased serum cholesterol compared to SP, while coconut oil enhanced serum and VLDL-C, and decreased LDL-C/HDL-C compared to corn oil. Dietary proteins interacted with dietary lipids to modulate HDL-C levels. Thus, FP maintained a high level of HDL-C regardless of lipid origin, compared to CA and SP whose HDL-C levels were decreased by corn oil, compared to coconut oil. A dietary protein-lipid interaction was also observed in the regulation of liver cholesterol levels. Coconut oil, compared to corn oil, decreased liver cholesterol in rabbits fed FP, whereas hepatic cholesterol concentration was unaltered by dietary lipid source in CA- and SP-fed rabbits. These results demonstrate that dietary proteins act synergistically with dietary lipids to regulate cholesterol metabolism in the rabbit. This work was presented in part at the 74th Annual FASEB meeting held in Washington, D.C., April 1–5, 1990.     

Mechanisms mediating lipoprotein responses to diets with medium-chain triglyceride and lauric acid

Medium-chain triglycerides (MCT) are often used in specialized formula diets or designer fats because of their special properties. Yet their influence on lipid metabolis is not completely understood. In this two-period cross-over study, the effects of MCT (8∶0+10∶0) in contrast to a similar saturated fatty acid (12∶0) were compared. Eighteen healthy women ate a baseline diet [polyunsaturated (PUFA)/saturated fat=0.9] fer 1 wk. Then, they consumed test diets (PUFA/saturated fat=0.2) for 4 wk. Monounsaturated fat and cholesterol were constant in baseline and treatment diets. MCT and 12∶0, substituted for part of the PUFA, provided 14 energy (en)% of the test diets. In comparison to the PUFA baseline diet, a 16% increase in mean serum low density lipoprotein (LDL)-cholesterol (C) on the 12∶0 diet was accompanied by a 21% decrease in mean receptormediated degradation of LDL by freshly isolated mononuclear cells (MNC) in vitro. The MNC assay theoretically gives an indication of receptor-mediated degradation of LDL. In contrast, the MCT diet raised mean receptor-mediated degradation of LDL by 42%, a finding out of line with the mean 11% increase in serum LDL-C. Perhaps MCT, by increasing the rate of LDL-C production, overcame the rate of LDL-C clearance. The 12∶0 diet enhanced some factors involved in reverse cholesterol transport (e.g., high density lipoprotein fractions) while MCT had a different of less pronounced effect. The overall effects of MCT on cholesterol metabolism may or may not be desirable, whereas those of 12∶0 appear largely undesirable as previously reported.     

Lipidemic effects of an interesterified mixture of butter, medium-chain triacylglycerol and safflower oils

The objective of this study was to determine if the positional structure of dietary triacylglycerol affected lipidemic responses. Thirty healthy adults (16 men and 14 postmenopausal women) with low-density lipoprotein cholesterol (LDL-C) concentrations >3.37 mM (130 mg/dl) enrolled in a prospective, single-blind, cross-over outpatient clinical trial that consisted of two 5-wk dietary phases. After baseline screening, subjects were instructed to follow individualized meal plans (weight maintenance diets with 36% of total energy from fat, half of which was from a test oil) and randomized to receive either butter (B) or an interesterified mixture (IM) of butter, medium-chain triacylglycerol (MCI), and safflower oils. Blood drawn during weeks 5 and 10 of feeding was analyzed for total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), LDL-C, and triacylglycerols (TAG). Mean plasma levels of TC (B, 6.98±1.06 mM; IM, 7.09±1.20 mM), HDL-C (B,1.30±0.35 mM; IM, 1.29±0.34 mM), and LDL-C (B, 4.91±0.95 mM; IM, 492±1.10 mM) were not significantly different between the two dietary treatments. Mean TAG levels were higher for the interesterified B-MCT mixture (B, 1.75±0.72 mM; IM, 1.96±0.86 mM, P<0.05). We conclude that an IM of B, MCT and safflower oils as compared to native B has no appreciable effect on plasma cholesterol concentrations but is associated with a modest rise in plasma TAG.     

Statin Treatment Improves Plasma Lipid Levels but not HDL Subclass Distribution in Patients Undergoing Percutaneous Coronary Intervention

Despite the established efficacy of statin therapy, the risk of cardiovascular events remains high in many patients. We examined high-density lipoprotein (HDL) subclass distribution profiles among statin-treated coronary heart disease (CHD) patients undergoing percutaneous coronary intervention (PCI). Plasma HDL subclasses were measured in 85 patients with established CHD and quantified by two-dimensional gel electrophoresis and immunoblotting. In CHD patients with statin treatment, the mean value of total cholesterol (TC) reached the desirable level and the triacylglycerol level (TAG) was borderline high. Moreover, low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), apolipoproteinA-I, and apolipoproteinB-100 levels in these patients resembled those in normolipidemic healthy subjects. The HDL subclass did not show a normal distribution and was characterized by the lower large-sized HDL_2b contents and higher contents of small-sized preβ₁-HDL in CHD patients, compared to those in normolipidemic control subjects. Multiple stepwise regression analysis revealed that the severity of coronary stenosis, determined by the Gensini Score, was significantly and independently predicted by HDL_2b and HDL_3b. Statin therapy was effective in modifying plasma lipids levels, but not adequate as a monotherapy to normalize the HDL subclass distribution phenotype of patients with CHD undergoing PCI. The HDL subclass distribution may aid in risk stratification, especially in patients with CHD and therapeutic LDL-C and HDL-C levels.     

Effects of dressing containing plant sterol on serum cholesterol concentration and the safety evaluation in borderline or mildly hypercholesterolemic Japanese subjects

In a placebo-controlled double-blind study, we examined the effects of dressing containing plant sterol (PS) on blood lipids and the safety in Japanese borderline or mildly hypercholesterolemic subjects. Fifty-nine subjects [total cholesterol (TC) concentration > or = 200 mg/dL] were randomly divided into two groups and were given daily 15 g of dressing containing 800 mg of PS [PS(+)-group] or without PS [PS(-)-group] for 12 weeks. Every 4 weeks, fasting blood was examined and subjective symptoms were analyzed. Serum TC, low-density lipoprotein cholesterol (LDL-C) and apolipoprotein B (ApoB) concentrations did not change in the PS(-)-group, while TC and ApoB significantly decreased in the PS(+)-group at 8 and 12 weeks and LDL-C at 4, 8 and 12 weeks. Moreover, serum TC, LDL-C and ApoB concentrations were significantly lower than those of PS(-)-group at 8 and 12 weeks. Other laboratory tests were all in normal ranges and no adverse events were observed. The results indicated that PS-containing dressing decreased serum TC, LDL-C and ApoB concentrations in borderline or mildly hypercholesterolemic subjects. It is therefore proved that the dressing containing PS is helpful in maintaining blood cholesterol level normal and hence, the health of Japanese.     

Low fat-monounsaturated rich diets containing high-oleic peanuts improve serum lipoprotein profiles

Postmenopausal hypercholesterolemic women are at risk for cardiovascular disease and are encouraged to follow low-fat (LF) (≤30% energy) diets. However, these diets may have undesirable effects on high density lipoprotein cholesterol (HDL-C), apolipoprotein A-I (apo A-I) and triglycerides, whereas diets high in monounsaturated fats do not. Twenty postmenopausal hypercholesterolemic women previously consuming high-fat diets (34% energy) were placed on a low fat-monounsaturated rich diet (LFMR: 26%, 14% energy, respectively) for 6 mon. Sixteen women already eating LF diets (24% energy) were also followed to monitor variations in serum lipids due to seasonal variations. Twenty-five women successfully completed the study (LFMR=12, LF=13). Serum cholesterol decreased 10% (264 to 238 mg/dL, P≤0.01) and low density lipoprotein cholesterol (LDL-C) decreased 12% (182 to 161 mg/dL, P≤0.01) in the LFMR group, but did not change in the LF group. The reduction in serum cholesterol in the LFMR group was greater than estimated by predictive formulas. Serum triglycerides and apo A-I did not change in the LFMR group. A modest decrease in HDL-C, HDL₃-C, and apolipoprotein B (apo B) occurred in both groups, but only the LFMR group showed a trend toward beneficial changes in LDL-C/HDL-C and apo A-I/apo B ratios. Overall, the LFMR diet was well tolerated and resulted in an improved serum lipid and apolipoprotein profile. A portion of this material was presented earlier at the annual meeting of the American Oil Chemists’ Society and in abstract from (O’Byrne, D.J., Shireman, R.B., and Knauft, D., 1993. The effects of a low-fat/high-oleic acid diet on lipoproteins in postmenopausal hypercholesterolemic women. INFORM 4(4), 553, #SS7).     

A Cross-sectional Study on the Relationship Between Homocysteine and Lipid Profiles Among Chinese Population from Hunan

Previous studies have explored the relationship between homocystein (Hcy) and lipid profiles. However, the results from these studies have been inconsistent. The current study investigated the correlation between Hcy and lipid profiles in Chinese community-based population. The participants were composed of 4012 Chinese people aged 30–92 years old, who were recruited from rural and urban communities in the Hunan Province. Non-parametric test and logistic regression were used to examine the distribution of Hcy and lipid profiles (triglyceride [TG], total cholesterol [TC], low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C]) and the relationship between them. The median age of subjects was 54.50 years old, and 40.98% were male. Median Hcy was 13.20 μmol/L, and 35.39% had hyperhomocysteinemia (HHcy). Median TG was 1.51 mmol/L, TC was 4.77 mmol/L, LDL-C was 2.62 mmol/L, and HDL-C was 1.27 mmol/L. In multivariable logistic regression analysis, HHcy was associated with high levels of TG (OR_male = 2.240, p < 0.001; OR_female = 2.539, p < 0.001), TC (OR_male = 2.237, p < 0.001; OR_female = 2.202, p < 0.001), and LDL-C (OR_male = 1.413, p = 0.010; OR_female = 1.617, p < 0.001) in the different sexes population and low level of HDL-C in females (OR = 1.326, p = 0.023) after adjusting for confounders. HHcy was independently associated with an increasing risk of low HDL-C among females. The regression analysis showed that HHcy was also associated with hypertriglyceridemia, hypercholesterolemia, and high level of LDL-C in males and females from Chinese community-based population, which provides a basis for the treatment and prevention of abnormal lipid metabolism.     

Plasma folate levels are associated with the lipoprotein profile: a retrospective database analysis

Background

Several studies demonstrated an association of homocysteine plasma levels and the plasma lipoprotein profile. This cross-sectional pilot study aimed at analyzing whether blood levels of the two important cofactors of homocysteine metabolism, folate and vitamin B12, coincide with the lipoprotein profile.

Methods

In a retrospective single center approach, we analyzed the laboratory database (2003-2006) of the University Hospital Bonn, Germany, including 1743 individuals, in whom vitamin B12, folate and at least one lipoprotein parameter had been determined by linear multilogistic regression.

Results

Higher folate serum levels were associated with lower serum levels of low density lipoprotein cholesterol (LDL-C; Beta = -0.164; p < 0.001), higher levels of high density lipoprotein cholesterol (HDL-C; Beta = 0.094; p = 0.021 for trend) and a lower LDL-C-C/HDL-C-ratio (Beta = -0.210; p < 0.001). Using ANOVA, we additionally compared the individuals of the highest with those of the lowest quartile of folate. Individuals of the highest folate quartile had higher levels of HDL-C (1.42 ± 0.44 mmol/l vs. 1.26 ± 0.47 mmol/l; p = 0.005), lower levels of LDL-C (3.21 ± 1.04 mmol/l vs. 3.67 ± 1.10 mmol/l; p = 0.001) and a lower LDL-C/HDL-C- ratio (2.47 ± 1.18 vs. 3.77 ± 5.29; p = 0.002). Vitamin B12 was not associated with the lipoprotein profile.

Conclusion

In our study sample, high folate levels were associated with a favorable lipoprotein profile. A reconfirmation of these results in a different study population with a well defined status of health, diet and medication is warranted.