POWER VARIATION OF SUBFRACTIONAL BROWNIAN MOTION AND APPLICATION

In this paper, we consider the power variation of subfractional Brownian mo- tion. As an application, we introduce a class of estimators for the index of a subfractional Brownian motion and show that they are strongly consistent.

Impact of Smoking Status on Lipoprotein Subfractions： Data from an Untreated Chinese Cohort

Objective Cigarette smoking is one of the established risk factors of atherosclerotic cardiovascular disease, however, its impact on lipids is not completely understood, especially in the Chinese population. Therefore, this study evaluated the impact of smoking status （non, former, and current smoking） on the distribution of lipoprotein subfractions in untreated patients with angina-like chest pain. Methods A total of 877 patients were consecutively enrolled and divided into nonsmoking （n = 528）, former smoking （n = 103）, and current smoking （n = 256） groups. Both low- and high-density lipoprotein cholesterol （LDL-C and HDL-C） subfractions were measured using the Quantimetrix Lipoprint System. The distributions of lipoprotein subfractions were evaluated among the groups. Results Compared with nonsmoking subjects, the current smoking group had significantly lower large/medium HDL-C （both P 〈 0.001） concentration and large HDL subfraction percentage but higher small HDL-C and medium LDL-C concentrations as well as medium LDL subfraction percentage. Importantly, former smoking subjects showed elevated levels of large HDL-C concentration, large HDL particle percentage, and mean LDL particle size and attenuation in small HDL/LDL percentages and small LDL-C concentration, but these levels did not reach the optimal status compared with those of the non-smoking group （data not shown）. Conclusion Smoking has an adverse impact on the lipoprotein subfractions, presented as lower large HDL particles besides higher small HDL and medium LDL particles, whereas smoking cessation could reverse these change to a certain degree.

Effects of Pitavastatin on Lipoprotein Subfractions and Oxidized Low-density Lipoprotein in Patients with Atherosclerosis

It has been demonstrated that pitavastatin can significantly reduce low-density lipoprotein(LDL)cholesterol(LDL-C),but its impact on lipoprotein subfractions and oxidized low-density lipoprotein(oxLDL)has not been determined.The aim of the present study was to investigate the potential effects of pitavastatin on subfractions of LDL and high-density lipoprotein(HDL)as well as oxLDL in untreated patients with coronary atherosclerosis(AS).Thirty-six subjects were enrolled in this study.O f them,18 patients with AS were administered pitavastatin 2 mg/day for 8 weeks and 18 healthy subjects without therapy served as controls.The plasma lipid profile,lipoprotein subfractions and circulating oxLDL were determined at baseline and 8 weeks respectively.The results showed that pitavastatin treatment indeed not only decreased LDL-C,total cholesterol(TC),triglycerides(TG)and apolipoprotein B(ApoB)levels,and increased HDL cholesterol(HDL-C),but also reduced the cholesterol concentration of all of the LDL subfractions and the percentage of intermediate and small LDL subfractions.Meanwhile,pitavastatin could decrease plasma oxLDL levels.Furthermore,a more close correlation was found between oxLDL and LDL-C as well as LDL subfractions after pitavastatin treatment.We concluded that a moderate dose of pitavastatin therapy not only decreases LDL-C and oxLDL concentrations but also improves LDL subfractions in patients with AS.

Influence of poloxamer 407 on fractional and subfractional composition of serum lipoproteins of mice

Using a novel small-angle X-ray scattering (SAXS) method for determination of fractional and subfractional composition of lipoproteins (LPs), a significant elevation of total cholesterol-lipop- roteins (C-LP) and, especially, total triglyceride- lipoproteins (TG-LP), was shown in this work. Among the LP fractions, poloxamer 407 was shown to significantly increase proatherogenic total C-LDL, TG-LDL and, especially, their precursors C-VLDL and TG-VLDL, while only exhibiting a moderate increase in the antiatherogenic C-HDL and TG-HDL fractions. With regard to the VLDL subfractions, significant elevations were observed in both subfractions studied;namely, C-VLDL1-2 and C-VLDL3-5. Similar chang- es were noted in the TG-VLDL1-2 and TG- VLDL3-5 subfractions. The C-IDL and TG-IDL subfractions were increased significantly (?20- to 30- fold), while the C-LDL1-3 subfraction was moderately (?3- to 5-fold) increased at 48 hrs and at day 4. In the moderately elevated (?2- to 4-fold) anti-atherogenic HDL fraction, the C-HDL2 subfraction was increased more significantly (?4- fold) compared to the C-HDL3 subfraction;how- ever, both C-HDL subfractions returned to base- line by day 4. The elevation in the TG-HDL2 subfraction was observed only at 24 hrs. Mouse models of hyperlipidemia and atherosclerosis are useful to evaluate the role of “individual” LPs, as well as their fractions and subfractions, in hyperlipidemia and the genesis of atherosclerosis.

Comparison of the effects of 3 kinds of oils rich in omega-3 polyunsaturated fatty acids on glycolipid metabolism and lipoprotein subfractions

Dietary omega-3 polyunsaturated fatty acids(ω-3 PUFAs)can be classifi ed into animal-and plant-derivedω-3 PUFAs.Patients with type 2 diabetes(T2DM)are frequently accompanied by dyslipidemia,which is closely related to the high-density lipoprotein(HDL-C)subfractions change.This study aimed to determine the effects of different sourcesω-3 PUFAs on glucolipid metabolism and lipoprotein subfractions in T2DM with dyslipidemia.Ninety T2DM patients with dyslipidemia were randomly assigned to take 3 g/day fi sh oil(FO,containing eicosapentaenoic acid(EPA)and docosahexaenoic acid(DHA)),3 g/day perilla oil(PO,containingα-linolenic acid(ALA)),or 3 g/day blend oil(BO,containing EPA,DHA and ALA)for 3 months.90 patients completed the intervention.There was a significant reduction of glycated hemoglobin(HbA1c)in all the groups.The triglycerides(TG)in the FO group were signifi cantly different with a group×time interaction(P=0.043),which was higher compared with the other two groups.The serum small HDL-C subfractions in the PO group was higher and the serum large HDL-C subfractions in the PO group was lower than those in the BO and FO groups.Plant-derivedω-3 PUFAs are more effective at controlling blood glucose than animal-derivedω-3 PUFAs.However,animal-derivedω-3 PUFAs have a signifi cant lowering effect on TG compared with plant-derivedω-3 PUFAs.Particularly,large HDL-C subfractions after animal-derivedω-3 PUFAs intake were higher than plant-derivedω-3 PUFAs intake;while small HDL-C subfractions were lower.Both the animal-and plant-derivedω-3 PUFAs have practical value in improving glucose and lipids metabolism in T2DM patients with dyslipidemia.

A note on approximation to subfractional brownian motion

Abstract:Subfractional Brownian motion can be decomposed in distribution as a sum of independent fractional Brownian motion and a centered Gaussian process with absolutely continuouspaths.This paper proves an approximations of subfractional Brownian motion using the decomposition.

Concentration-induced structural diversity and catalytic activity of BF3/n-BuOH complexes for n-decene polymerization

The BF3/n-BuOH complexes were investigated as active species in catalyzing n-decene polymerization reaction.The structures of BF3/n-BuOH complexes were characterized not only by modern spectrum but also by calculation at theoretical level. The results confirmed that BF3/n-BuOH complexes changed from BF3·(n-BuOH)2 complexes to BF3·n-BuOH complexes with the mass fraction of BF3 increasing. These two complexes have different catalytic activity, but BF3·n-BuOH was superior. The highest n-decene conversion could reach 99% and the most excellent selectivity of n-decene trimer and tetramer could reach up to 80% yield by a series of controlled conditions. This work can help to understand the catalytic active species of n-decene polymerization and provide support for industrialization of poly-alpha-olefins(PAOs).

百里香萃取物的体外抗自由基活性研究

对百里香的丙酮提取物的乙酸乙酯和正丁醇萃取物成分的体外抗氧化活性进行了研究,两者的总抗氧化力、羟自由基、Fe3+还原力和由AAPH和CuSO4诱导的大豆卵磷脂的过氧化抑制进行了比较。结果表明,乙酸乙酯和正丁醇萃取物成分均有较强的抗氧化能力,主要为低分子量的黄酮类化合物,且抗氧化能力呈浓度效应;乙酸乙酯萃取物的抗氧化能力明显强于正丁醇萃取物。百里香可作为一种新型的天然抗氧化剂资源。

垂盆草不同提取部位保肝降酶试验

目的 :确定垂盆草的活性部位 ,为保肝降酶活性组分的筛选提供线索和依据。方法 :用 80 % Et OH对原药材进行回流提取 ,然后 ,依次用 Pet、Et OA c、n-Bu OH对垂盆草药材的醇浸膏进行萃取 ,分别制得 Pet部分、Et OAc部分、n-Bu OH部分和 H2 O部分 ,通过保肝降酶试验 ( D-氨基半乳糖致小鼠急性肝损伤 ) ,考察其活性部位。结果 :实验表明 ,H2 O部分及 n-Bu OH部分高剂量组降酶作用有极显著意义 ( P<0 .0 1) ,Et OA c部分高剂量组对降 AL T有显著意义 ( P<0 .0 5 )。结论 :垂盆草中具有保肝降酶作用的活性成分主要存在于 H2 O部分和 n-Bu OH部分。

热重法考察渣油及其亚组分的焦化性能

以热重法考察锦州石化渣油及其亚组分的焦化性能,并揭示了渣油各亚组分间的焦化物理化学作用。结果表明,四组分焦化生焦率从大到小的顺序为沥青质、胶质、芳香分、饱和分;渣油的生焦率介于芳香分和胶质之间。焦化过程中表观热裂化反应活性顺序为饱和分>芳香分>胶质>沥青质,而实际热裂化剧烈程度的顺序相反。饱和分可促进其它亚组分生焦,而芳香分可抑制胶质、沥青质生焦;渣油按四组分组成物理加权后的生焦率大于该渣油的生焦率。还探讨了渣油及其亚组分在焦化过程中的动力学特征。

低密度脂蛋白亚组分氧化易感性的检测及临床应用

建立低密度脂蛋白（ＬＤＬ）氧化产物共轭双烯（ＣＤ）检测法，对反应条件进行选择，并初步应用于临床。根据ＬＤＬ氧化产生的ＣＤ量随时间变化绘制氧化曲线，观察延滞时间，ＣＤ最大生成率及总ＣＤ值。资料表明：冠心病患者Ｂ型ＬＤＬ亚组分较Ａ型延滞时间明显缩短；总氧化值亦显著升高。认为冠心病患者Ｂ型ＬＤＬ较Ａ型易于氧化，且氧化程度增高，促进动脉粥样硬化的发生。低密度脂蛋白氧化易感性的检测对了解ＬＤＬ的氧化过程和防治心脑血管疾病有参考价值。

荷丹片对高脂血症患者血脂谱、PCSK9水平及高密度脂蛋白颗粒的影响

目的观察荷丹片对高脂血症患者血脂谱、前蛋白转化酶枯草溶菌素9(PCSK9)以及高密度脂蛋白(HDL)亚型的影响。方法 37例高脂血症患者随机入选荷丹组(荷丹片4.38 g/d,n=18)和安慰剂组(n=19),治疗8周后,分别检测血脂谱、PCSK9以及HDL亚型的变化。结果荷丹片治疗8周可轻度降低低密度脂蛋白胆固醇(LDLC)水平,但对总胆固醇(TC)、甘油三酯(TG)以及高密度脂蛋白胆固醇(HDLC)水平及血浆PCSK9水平无影响。但是,经荷丹片治疗后HDLC大颗粒亚型的浓度及大颗粒亚型的比例增加,HDLC小颗粒亚型的浓度及比例减少,但HDLC的血浆水平无变化。结论荷丹治疗8周可以改善LDLC水平以及HDLC的亚型浓度及比例。

LDL氧化易感性与体内氧化LDL水平相关性分析

目的 :探讨体内氧化低密度脂蛋白 (Ox LDL)水平与LDL亚组分氧化易感性之间的关系。 方法 :采用序列超速离心分离 2 2例冠心病 (CHD)患者及 2 0例对照组血浆LDL ,体外Cu2 + 介导的LDL氧化分析其氧化易感性的变化 ;ELISA法检测体内Ox LDL水平。 结果 :CHD患者LDL氧化的延滞时间及总氧化值显著升高 ,氧化速率无变化 ;致密LDL氧化的延滞时间及总氧化值亦不同于轻的LDL。CHD患者Ox LDL水平显著升高 (5 39.1± 15 5 .6vs(318.0± 15 9.6 ) μg/L(P <0 .0 1)。Ox LDL水平同致密LDL氧化的延滞时间呈负相关 (r =- 0 .4 8,P <0 .0 5 ) ,同轻的LDL氧化的延滞时间不相关。Ox LDL水平同致密LDL的蛋白质浓度有相关趋势 (r=- 0 .4 2 ,P =0 .0 5 3)。 结论 :高浓度的小而密的B型LDL ,因易于氧化导致体内Ox LDL水平升高 ,促进了动脉粥样硬化 (As)的发生。

胜利渣油族组分热转化动力学

采用动态热分析方法在线性升温速率为6.20K/min及惰性报气流率为100 cm^3/min的条件下考察了胜利渣油四个族组分的热转化行为.结果表明,其热转化活性变化顺序为:饱和分>芳香分>胶质>沥青质.四组分中饱和分可生成少量焦炭,芳香分的生焦率高于前者,胶质及沥青质是焦炭的主要来源.在723K时,两者的生焦率分别为29.0％及44.1％.在热转化过程的两个温度区间内,可利用两个独立的一级动力学模型对实验数据进行拟合.借助线性回归分析,确定了四组分在两个温区内的动力学参数.

含聚污水中乳化活性亚组分的分析及污水稳定性研究

用石油醚和三氯甲烷依次萃取含聚污水中的油分,然后用石油醚沉淀及甲醇/异丙醇抽提,将两个组分分成六个亚组分。表征了六个亚组分的结构组成,研究了亚组分的乳化性能,考察了水相组成对高酸值亚组分SF31所形成乳状液稳定性的影响。研究结果表明,固体亚组分SF41和SF42的H/C低,相对分子质量高,杂原子含量高,金属钙、铁含量高(SF42相对分子质量高达4 533,杂原子含量25.3%,钙、铁含量分别达到2 357 mg/kg、455.8 mg/kg),液体亚组分SF1和SF31酸值高(SF31酸值高达23.9 mg KOH/g),这些亚组分都有很强的乳化能力,在一定浓度范围内,乳化活性弱的亚组分SF2对乳化活性强的亚组分的乳化有一定的抑制作用,酸值高的亚组分是导致含聚污水油含量高的主要因素。当水相HPAM含量超过200 mg/L时,乳状液很稳定;盐含量超过1 800 mg/L以后,含HPAM的乳状液稳定性增强,盐含量超过7 000 mg/L后,Zeta电位变成正值。

甲胎蛋白异质体对原发性肝细胞癌的诊断价值

通过扁豆凝集素亲和双向免疫电泳,对47例原发性肝细胞癌(PHC),40例良性肝病,6例转移性肝癌血清AFP异质体进行研究,发现PHC患者血清扁豆凝集素结合型AFP为43.298±22.4%,明显高于良性肝病患者(10.35±17.053%)及转移性肝癌患者(4.167±6.646%)。以该值大于25%为诊断肝癌标准,则阳性率为82.98%特异性为90%。在14例AFP为阴性的PHC患者中,有10例该值大于25%,其阳性率为71.43%。对PHC患者行肝动脉栓塞术后其扁豆凝集素结合型AFP降低,故可用其做为观察疗效的指标。

新诊断2型糖尿病患者血脂谱和低密度脂蛋白亚组分特征及与慢性并发症关系

目的 探讨新诊断 2型糖尿病患者血脂谱和低密度脂蛋白 (LDL)亚组分的特征及与慢性并发症的关系。方法 采用横断面研究 ,调查 175例新诊断的 2型糖尿病患者 (糖尿病组 )和 39名无高血压、糖尿病和血脂异常的正常人 (正常对照组 )。分别测定两组的身高、体重、血压、腰围、腰臀比、血糖、血脂 ,并采用 2 %～ 16 %聚丙烯酰胺梯度凝胶电泳 (PAGE)法检测LDL颗粒直径。对糖尿病组患者进行眼底、尿微量白蛋白、尿肌酐和颈动脉、股动脉、髂总动脉内 中膜厚度 (IMT)检查。结果 糖尿病组总胆固醇 (TC)和三酰甘油 (TG)水平均明显高于正常对照组 [TC :(4 .5 9± 0 .80 )mmol/L∶(4 .32± 0 .5 4 )mmol/L ;TG :(1.91± 1.15 )mmol/L∶(0 .89± 0 .2 9)mmol/L ,P值均 <0 .0 5 ];LDL颗粒直径明显小于正常对照组 [(2 6 .5 9± 1.18)nm∶(2 7.4 3± 1.2 4 )nm ,P <0 .0 5 ]。相关和多元逐步回归分析显示 ,TG与LDL颗粒直径成负相关 ,且是LDL颗粒直径的主要影响因素。糖尿病组中 ,伴有大血管病变者的LDL颗粒直径明显小于不伴有大血管病变者。Logistic回归模型分析显示 ,LDL颗粒直径变小是糖尿病患者发生大血管病变的主要危险因素之一。结论 新诊断的 2型糖尿病患者普遍存在血脂紊乱 ,TG升高是LDL颗粒直径变小的主要影?

2型糖尿病HDL2b的变化特点及对预测冠心病风险的意义

目的探讨2型糖尿病(type 2 diabetes mellitus,T2DM)患者血清高密度脂蛋白(high-density lipoprotein,HDL)亚组分HDL2b的变化特点及对预测冠状动脉粥样硬化性心脏病(coronary heart disease,CHD)风险的意义。方法采用病例对照研究的方法观察41例T2DM患者及41例空腹血糖正常(normal fasting glucose,NFG)对照者,病例均来自于北京市顺义区南法信镇35～74岁自然人群,2组研究对象的年龄、性别、体质量指数(body mass index,BMI)、腰围、臀围、血压均匹配,采用微流芯片(microfluidic chip)技术测定空腹血清HDL、HDL2b、HDL2b/HDL比率,并对10年CHD发生风险(10-year CHD risk)进行评估。结果 T2DM组患者空腹血糖(fasting plasma glucose,FPG)、稳态模型胰岛素敏感指数(homeostasis model for insulin resistance,HOMA-IS)、胰岛素抵抗指数(homeostasis model assessment-insulin resistant index,HOMA-IR)、三酰甘油(triglycerides,TG)、血清总胆固醇(total cholesterol,TC)、10年CHD发生风险均显著高于对照组(P<0.05),HDL、HDL2b、HDL2b/HDL比率显著低于对照组(P<0.01),HDL2b与FBG、空腹胰岛素(fasting insulin,FINS)、TG、TC、HOMA-IR、10年CHD发生风险呈负相关,HDL2b与FBG及10年CHD发生风险相关性优于HDL。结论 T2DM患者HDL2b显著降低,10年CHD发生风险显著上升,与HDL相比,HDL2b预测CHD发生风险更加敏感。

原油活性组分及相互作用对乳状液稳定性影响的研究进展

原油生产过程中,活性组分易使原油形成大量乳状液,主要包括沥青质、胶质、石油酸和蜡等。基于这些活性组分的组成与存在状态,阐述了各活性组分对乳状液稳定性的影响机制,重点剖析了各活性组分与沥青质间的相互作用及其对乳状液稳定性的影响。指出沥青质是构成界面膜的主要成分,适量的胶质能对沥青质起到协同乳化的作用。不同相对分子质量的石油酸与沥青质相互作用的结果也不同,蜡组分在结晶或与沥青质相互作用时能增强界面膜的强度。最后提出了目前存在的问题,并展望了发展趋势。

中风急性期血清血脂脂蛋白亚组分与辨证关系

观察５５例急性期中风患者血清血脂及其亚组分胆固醇的变化，结果缺血性甘油三脂（ＴＧ）、胆固醇（ＴＣ）、低密度脂蛋白胆固醇（ＬＤＬ－ｃ）、极密度脂蛋白胆固醇（ＶＬＤＬ－ｃ）明显高于出血性中风（Ｐ＜０．０５～０．００１）；高密度脂蛋白胆固醇（ＨＤＬ－ｃ）则出血性高于缺血性中风；但ＨＤＬ２－ｃ降低则是两者的共同特点。ＨＤＬ－ｃ、ＨＤＬ２－ｃ、ＨＤＬ２－ｃ／ＨＤＬ３－ｃ呈风火上扰＞痰瘀痹阻＞气虚血瘀；ＬＤＬ－ｃ、ＴＣ／ＨＤＬ－ｃ、ＴＣ－ＨＤＬ．ｃ／ＨＤＬ．ｃ、ＬＤＬ－ｃ／ＨＤＬ－ｃ则呈气虚血瘀＞痰瘀痹阻＞风火上扰。提示中风患者的防治，在调升ＨＤＬ－ｃ过程中，提高ＨＤＬ２－ｃ的临床意义更大；中风虚证患者动脉粥样硬化程度较实证者重，补虚化瘀是防治中风的重要法则，调治血脂代谢异常是化瘀通络的重要途径。