Copolyimide molecular brushes with poly(methacrylic acid) side chains as additive to polyphthalamide membrane: Organization,physical, and transport properties

Macromolecules of complex architecture find application as modifiers of commercial polymeric membrane materials. In this work, copolyimide molecular brushes (coPI) composed of polyimide backbone and poly(methacrylic acid) side chains were used to modify poly(m-phenylene iso-phthalamide) (PPA). Structure, physical, mechanical, and transport properties of dense nonporous PPA/coPI membranes containing up to 10 wt% coPI were studied. The effect of included coPI on the membrane structure was estimated using atomic force microscopy and mechanical tests. The coPI modifier contributes to the additional formation of free volume elements evenly distributed throughout the membrane. Transport properties of PPA/coPI membranes were investigated via sorption tests and pervaporation separation of methanol (MeOH) and methyl tert-butyl ether (MTBE) mixtures. The inclusion of coPI modifier in the PPA membrane leads to an increase in the total flux of the membrane. The highest separation factor was found for the PPA/coPI membrane containing 10 wt% coPI; transport properties of the best membrane were compared with the literature data on separation of the azeotropic MeOH–MTBE mixture.     

π-π Interactions,Architecture, and Bandwidths in “Molecular Metals”. A Synthetic and Electronic Structure Study of Monomeric and Cofacially Joined Dimeric Germanium Phthalocyanines

Small molecule spectroscopy on M(Pc)(OR)₂ and ROM(Pc)OM(Pc)OR molecular fragments (M = Si, Ge; Pc = phthalocyaninato) of the conductive polymer [M(Pc^p+)O]_n provides a unique probe of the band structure-forming π-π interactions. We describe here the synthesis and characterization of the M = Ge monomer and dimer where R = (t-Bu)Me₂Si-. The lowest energy He I photoelectron spectroscopic feature of the dimer is a doublet with a splitting of 0.19(3) eV. This splitting can be associated with the cofacial HOMO-HOMO Pc-Pc interaction and translates into a tight-binding bandwidth in the polymer of 0.38(6) eV. This result is in good agreement with an experimental bandwidth of 0.48(5) eV obtained from a Drude analysis of the {[Ge(Pc)0]I_1.1}_n reflectance spectrum and a bandwidth of 0.50 eV derived from theoretical calculations.     

Characterisation of acorn oils extracted by hexane and by supercritical carbon dioxide

Acorn fruit oils from two species of oak, Quercus rotundifolia L. (holm‐oak) and Quercus suber L. (cork‐oak), were extracted by n‐hexane. The acorn fruit of Quercus rotundifolia L. was also extracted by supercritical CO₂ at 18 MPa and 313 K, a superficial velocity of 2.5 × 10^?4 ms^?1, and a particle size diameter of 2.7 × 10^?4 m. The oils were characterised in terms of fatty acids, triglycerides, sterols, tocopherols, and phospholipids. The main fatty acid in both fruit species was oleic acid (about 65%), followed by linoleic acid (about 16.5–17%) and palmitic acid (about 12.1–13.4%). The main triglyceride found in acorn oils was the OOO (oleic, oleic, oleic) triglyceride (33–38%), followed by the POO (palmitic, oleic, oleic) triglyceride (12.6–18.2%). In terms of sterols, the main component in acorn oils of both species was β‐sitosterol (83.5–89%), followed by stigmasterol (about 3%). However, in Quercus suber L., acorn oil was found to consist to 10.2% of campesterol. The amount of cholesterol was low (0.27% for the Quercus rotundifolia L. oil extracted by supercritical fluid extraction, and 0.18% for the oil extracted by n‐hexane). The Quercus suber L. acorn oil presented 0.1% of cholesterol. The total amount of tocopherols in Quercus rotundifolia L. acorn oils was almost the same when the oil was extracted by n‐hexane (973 mg/kg oil) or by supercritical CO₂ (1006 mg/kg oil). The Quercus suber L. acorn oil presented a high value of total tocopherols (1486 mg/kg oil). The supercritical CO₂ did not extract the phospholipids. The amount of phospholipids was very similar for both species of oak acorn oils extracted by n‐hexane. Oxidative stability was also studied, by using the peroxide value and the Rancimat method, revealing that all the oils were significantly protected against oxidation. The influence of storage, under several conditions, on the oxidative stability was also studied. The Quercus rotundifolia L. oil extracted by n‐hexane was better protected against oxidation after a few days of storage at 60 °C.     

Energy dissipation rate and pressure fluctuations in a three phase fluidized bed with a large column diameter

The effects of liquid (0.02-0.10 m/s) and gas (0.0-0.10 m/s) velocities and particle size (1.0, 2.3, 3.0 mm) on the pressure fluctuations and energy dissipation rate in three phase fluidized beds were determined in a large column (0.376 m-I.D.× 2.1 m high). The standard deviation of pressure fluctuations and energy dissipation rate increase with gas and liquid velocities but, decrease in the radial direction of three phase fluidized beds. The energy dissipation rate was well correlated with dimensionless groups as: E_d=16.788Fr ₁ ^0.183 Fr _g ^0.139 (1-ψ)^0.442+1.265Fr _g ^0.143 Re^0.181.     

Influence of sorghum wax,glycerin, and sorbitol on physical properties of soy protein isolate films

Sorghum wax, sorbitol, glycerin, and soy protein isolate (SPI) composite films were prepared. Effects of sorghum wax, sorbitol, and glycerin concentrations on various films were evaluated using response surface methodology. All independent variables significantly (P<0.05) affected film water vapor permeability (WVP), tensile strength (TS), elongation at break (E), total color difference, and total soluble matter (TSM). Increasing the sorghum wax concentration decreased WVP and E. As sorbitol content increased in the composite films, WVP and TS increased. Sorbitol had a critical point of 2–5 g/5 g SPI for low values of TSM. The addition of sorbitol contributed more to the properties of the film than did glycerin.     

Poly(p‐phenylene benzoxazole) fiber chemically modified by the incorporation of sulfonate groups

Two kinds of modified poly(p‐phenylene benzoxazole) (PBO), the copolymer of TPA (SPBO) and p‐SPBO, containing ionic groups in the macromolecular chains were obtained by copolymerization from 1,3‐diamino‐4,6‐dihydroxybenzene dihydrochloride (DAR) and terephthalic acid (TPA), with the addition of selected amounts (1.5–5.0% molar ratio over DAR) of 5‐sulfoisophthalic acid monosodium salt or sulfoterephthalic acid monopotassium salt in place of the TPA, respectively, in poly(phosphoric acid) (PPA). The resultant PBO/PPA, SPBO/PPA, and p‐SPBO/PPA lyotropic liquid‐crystalline solutions were spun into fibers by a dry‐jet wet‐spinning technique. Chemically modified PBO fibers with sulfonate salt pendants in the polymer chains were obtained for the first time. The surface wetting behavior and interfacial shear strength between the fiber and epoxy resin were investigated. The interference of sulfonate salt pendants on the crystalline morphology was measured. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Farmer's view on soil organic matter depletion and its management in Bangladesh

Bangladesh is an agricultural country. About 80% of the total population live in rural areas. The contribution of agriculture to the gross domestic product is 30%. Rice is the major food crop while jute, sugarcane and tea are the main cash crops. Other important crops are wheat, tobacco, pulses, vegetables and fruits. Overall productivity in Bangladesh is stagnating or declining. The implication of yield stagnation or declining productivity is severe, since these trends have occurred despite rapid growth in the use of chemical fertilisers. Depletion of soil organic matter is the main cause of low productivity, which is considered one of the most serious threats to the sustainability of agriculture in Bangladesh. In Bangladesh, most soils have less than 17 g/kg and some soils have less than 10 g/kg organic matter. Farmers realise that there is a problem with soil fertility related to organic matter depletion. Farmers say that organic matter increases yield, reduces the production cost, improves crop growth and the economy, increases water-holding capacity and improves the soil structure. They recognise soil with higher organic matter content by darker brownish to black in colour. Some farmers are using fast-growing trees such as Flemingia macrophyla, Ipilipil (Leucaen leucophala), Glyricidia sepium, Boga Medula (Tephrosia candida), Dhol Kolmi (Ipomoea fistulosa), etc., as living fences, which can be used as fuel, fertiliser and fodder. To increase the soil organic matter, farmers use green manure crops, compost, quick compost, cow dung, azolla, etc. However, fuel for cooking purposes is limited and cow dung and crop residues are largely used as fuel. Crop residues are also used as fodder for livestock. Farmers expressed the wish to learn more about organic fertilizer management. However, sufficient food should be produced to keep pace with population growth. To alleviate the hunger and poverty is to increase the intensity of agricultural production and maintain favorable ecological conditions. Therefore, more organic matter should be used in the farmers' fields to sustain the soil fertility in an intensive farming system. This revised version was published online in June 2006 with corrections to the Cover Date.     

Variation in tannin activity of acorns of seven species of central florida oaks

Acorns of seven sympatric species of oaks (Quercus spp.) occurring in central Florida were compared for protein-precipitating ability (PPA). Husks and cotyledons of green and ripe acoms were analyzed. Few significant differences were found between green and ripe acorns of the same species. Cotyledons were significantly higher than husks in PPA in most of the species compared. All species exhibited high intraspecific variability in PPA. Significant differences between species were found in green and ripe cotyledons and in green husks. With the exception ofQ. minima, PPA of ripe cotyledons was higher in the subgenusErythrobalanus (red oaks) than the subgenusQuercus (white oaks).     

Thermal,static, and dynamic mechanical properties of bark cloth (ficus brachypoda) laminar epoxy composites

Bark cloth is a natural nonwoven fibrous fabric produced in Uganda from three species of trees: Ficus natalensis , Ficus brachypoda, and Antiaris toxicaria . The recently developed bark cloth composites has created a new class of textile composites which can find applications in interior automotive panels. Four bark cloth plies were utilized, the resin was infused using Vacuum Assisted Resin Transfer Molding (VARTM). Scanning Electron Microscopy was used to study the fabric's fiber morphology, surface functional groups were characterized using Fourier Transform Infrared. Overall, the static and the Dynamical mechanical analysis showed that the developed composites had a tensile strength ranging from 22 to 29 MPa whereas the flexural strength ranging from 45 to 100 MPa. The glass transition temperature of the composites was ranging from 53°C to 63°C. POLYM. COMPOS., 38:199–204, 2017. © 2015 Society of Plastics Engineers     

Mild steel green inhibition by Ficus carica leaves extract under practical field conditions

Various electrochemical techniques were employed to study the effectiveness of aqueous Ficus carica (Fig. tree) leaves extract as green corrosion inhibitor for mild steel under field conditions containing 3.5% sodium chloride solution saturated with carbon dioxide. Optimum inhibition efficiency of 90% was obtained using 50 mg/L of inhibitor in the temperature range of 25–40 °C. The mode of action of Ficus carica leave extract as revealed by Polarization studies was shown to act as a mixed inhibitor. The adsorption isotherm of the adsorption of Ficus carica leaves extract on the steel surface was found to follow Langmuir adsorption isotherm. In order to assess the individual contribution of the different constituents of the extract theoretically, the adsorption of the four major organic constituents of Ficus carica leave extract on mild steel were modelled using density functional theory and quench molecular dynamic simulations. Among the four major Ficus carica leaves extract constituent investigated, Caffeoylmalic acid was found to make the most contribution to the overall inhibition action of Ficus carica leaves extract.     

Circulating Lp(a):LDL Complexes Contain LDL Molecules Proportionate to Lp(a) Size and Bind to Galectin-1: A Possible Route for LDL Entry into Cells

The molecular mechanism of vascular pathology mediated by circulating lipoprotein(a) [Lp(a)] remains unknown. We examined the role of two distinguishing features of Lp(a) viz non‐covalent complex formation with a low density lipoprotein (LDL) and heavy glycosylation as determinants of binding of this lipoprotein and its LDL complex to cell‐surface receptors. LDL isolated from the Lp(a):LDL complex, free LDL and oxidized LDL were equally efficient in forming a reconstituted complex with pure Lp(a). Complexed LDL in healthy individuals was equal in oxidation status to free LDL. The number of LDL molecules associated with each Lp(a) molecule (LDL index) in plasma samples increased steadily with Lp(a) size (correlation coefficient r = 0.834). Complex reconstituted from purified plasma Lp(a) and LDL maintained the same LDL index as plasma in accordance with Lp(a) size. Consequently, the percentage of complex‐free Lp(a) in the plasma decreased sharply with Lp(a) size (r = ?0.887). Although O‐glycosylation measured in terms of lectin binding increased with Lp(a) size, the LDL index increased significantly faster than O‐glycosylation among Lp(a) phenotypes of different plasma samples. Complexes with varying stoichiometry existed in the same plasma. Extra LDL complex molecules were not recognized by LDL receptors on human macrophages or rat cardiac fibroblasts indicating attachment to Lp(a) involved LDL receptor‐binding sites. However, unlike free LDL complex LDL could attach through Lp(a) to immobilized form of galectin‐1, a lectin ubiquitous on mammalian cells. Results suggest that phenotype‐dependence of the physiological and pathological functions of Lp(a) may operate through differential LDL‐carrier activity.     

Novel fully conjugated 2H‐ and metal‐phthalocyanine network polymers: Synthesis,characterization, and dielectric spectra analysis

2,7‐di‐tert‐butylpyrene was oxidized to 2,7‐di‐tert‐butylpyrene‐4,5,9,10‐tetraone. The latter through condensation reactions with vicinal diamine such as 4,5‐diaminophthalonitrile produced heterocyclic monomer, 2,7‐di‐tert‐butyl pyrene[4,5][9,10]bisquinoxaline‐6,7‐dinitrile, which was cyclo‐tetramerized to the corresponding tetra[2,3‐(1,4‐diaza‐6,6‐di‐tert‐butylphenanthreno)[4,5]phthalocyanine]‐based network polymer (2H‐Pc), and tetra [2,3‐(1,4‐diaza‐6,6‐di‐tert‐butylphenanthreno)[4,5]phthalo‐cyaninato metal II‐based network polymers (M‐Pc, M= Co, Ni, Zn, or Cu). Elemental analytical results, IR and NMR spectral data of the new prepared molecules are consistent with their assigned formulations. Molecular masses and metal contents of the synthesized polymers proved to be of high molecular masses which confirm the efficiency of tetramerization polymerization and complexation reactions. The dielectric constant (ε′) and dielectric loss tangent (tan δ) were studied as a function of temperature and frequency. The detailed analysis of the results showed that the dielectric dispersion consists of both dipolar and interfacial polarization. Measurements of ac conductivity as a function of frequency at different temperatures revealed that the nonoverlapping small polaron tunneling is the most suitable mechanism for ac conduction behavior. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Soy protein combined with copper and boron compounds for providing effective wood preservation

Chromated copper arsenate (CCA), an arsenicbased wood preservative, is toxic to human health and the environment. Although CCA is stable in seasoned wood, there are potential dangers during CCA manufacture, lumber treatment, and waste disposal. This research was conducted to study the effectiveness of soy products to replace toxic chromium and arsenic compounds in wood preservative formulations. Three soy product (Arpro 2100, HM 90, and Supro 760) were used as fixative agents in preservative solutions containing anhydrous CuSO₄ and Na₂B₄O₇·10H₂O. The decay resistance of treated wood blocks was measured by a soil-block culture method. Despite the large molecular sizes of copper-protein and copper-boron-protein complexes, southern pine sapwood was treatable with these preservative formulations. Wood samples treated with >6 kg°m⁻³ CuSO₄ and 7.5 kg·m⁻³ soy product, and subsequently leached for 3 d and exposed to the decay fungus Gloeophyllum trabeum (Fr.) Mur., sustained only 0.5% weight loss over 12 wk. Wood samples needed 40 kg·m⁻³ CuSO₄ and 50 kg·m⁻³ soy protein to resist the copper-tolerant decay fungus Postia placenta (Fr.) M. Lars. & Lomb. These results suggest that soy-based wood preservatives can prevent wood products from fungal attack and can replace CCA.     

Synthesis, electro-spectroelectrochemical characterization and electrocatalytic behavior towards dioxygen reduction of a new water-soluble cobalt phthalocyanine containing naphthoxy-4-sulfonic acid sodium salt

A new water-soluble cobalt phthalocyanine, 2(3), 9(10), 16(17), 23(24)-tetrakis(4-(1-naphthoxy-4-sulfonic acid sodium salt)) phthalocyaninato cobalt(II) NhtCoPc, where Nht indicates naphthoxy-4-sulfonic acid sodium salt, was synthesized and its electro-spectroelectrochemical and electrocatalytic behavior towards oxygen reduction reaction were investigated in details. The complexation reaction was monitored with the UV-vis spectral changes of NhtH₂Pc in methanol solution. The reaction was completed when the main Q-band was observed in maximum intensity. The electrochemical studies showed that the cobalt complex exhibited two reversible one-electron reductions with the corresponding anodic wave and an irreversible oxidation reaction in DMSO solution. These reduction processes were assigned to Co(2+)Pc(2−)/Co(+)Pc(2−) and Co(+)Pc(2−)/Co(+)Pc(3−) couples, respectively. The well-defined UV-vis spectra of the mono-anionic species [NhtCo(+)Pc(2−)]⁻, di-anionic species [NhtCo(+)Pc(3−)]²⁻, and mono-cationic species [NhtCo(3+)Pc(2−)]⁺, were obtained by the applied potentials (E_app = −0.60, −1.40, and 0.70 V, respectively) in a thin-layer cell. NhtCoPc was incorporated into the conductive polyaniline (PAni) films as a dopant-anion during electropolimerization in acid medium, and thus formed the Pt/PAni-NhtCoPc electrode. This modified electrode was characterized by scanning electron microscopy (SEM), as well. The addition of NhtCoPc to the polymerization solution changes markedly the morphology of the films obtained and increases the redox-activity towards oxygen reduction of the PAni film formed compared to those of Pt/PAni and bare platinum electrodes in the same experimental conditions.     

Hydrophobicity, solubility, and emulsifying properties of soy protein peptides prepared by papain modification and ultrafiltration

Peptide size control is important for obtaining desirable functional properties so that these peptides can be better utilized. Proteolytic enzymatic modification of soy protein isolates (SPI), followed by ultrafiltration, is an effective way to fractionate these proteins into peptides with controlled molecular size. SPI was predenatured by mild alkali at pH 10 and heated at 50°C for 1 h prior to partial hydrolysis by papain at pH 7.0 and 38°C for 10, 30, and 60 min (PMSPI10, PMSPI30, and PMSPI60). The hydrolysate PMSPI60 was further fractionated by ultrafiltration with a stirred cell and disc membranes (100-, 50-, and 20-kDa molecular weight cut-off) into one retentate (R100) and three permeates (P100, P50, and P20). Molecular weight distribution, surface hydrophobicity (S ₀), protein solubility (PS), emulsifying activity index (EAI), and emulsion stability index (ESI) of the control SPI (without added papain), hydrolysates, and ultrafiltrates were investigated. Significant increases (P<0.001) in S ₀, PS, EAI, and ESI were observed in the hydrolysates. Peptides in the permeates had higher PS and EAI but lower S ₀ than the peptides in the retentate and hydrolysate. Soy protein peptides that were prepared from SPI by papain modification and ultrafiltration had lower molecular weight, higher solubility, and higher emulsifying properties. They could find use in products that require these properties, especially in the cosmetic and health food industries.     

Lipoprotein (a) metabolism estimated by nonsteady-state kinetics

Lipoprotein (a) [Lp(a)] is a low-density lipoprotein (LDL) particle with an additional apolipoprotein named apo(a). The concentration of Lp(a) in plasma is determined to a large extent by the size of the apo(a) isoform. Because elevated Lp(a) concentrations in plasma are associated with risk for premature coronary heart disease it is important to determine whether variations in production or catabolism mediate differences in Lp(a) concentration. We determined metabolic parameters of Lp(a) in 17 patients with heterozygous familial hypercholesterolemia or severe mixed hyperlipidemia by fitting a monoexponential function to the rebound of Lp(a) plasma concentration following LDL-apheresis. In 8 of those 17 patients this was done twice following two different aphereses. Although this approach allows one to estimate metabolic parameters without the use of a tracer, it requires several major assumptions such as that apheresis itself does not change production or catabolism of Lp(a) and that Lp(a) metabolism can be described by a single compartment. One apheresis decreased Lp(a) concentration by 59.1±8.3%. The fractional catabolic rate (FCR) was 0.16±0.12 d⁻¹ and production rate 6.27±5.26 mg·kg⁻¹·d⁻¹. However, observed (concentration before first apheresis) and predicted steady-state concentrations differed considerably (more than 20%) in 9 of 17 patients, indicating that not all assumptions were fulfille in all patients. Production rate but not FCR was correlated with Lp(a) plasma concentration (r ²=0.43. P=0.004) and molecular weight of apo(a) (r ²=0.48, P=0.011), which confirms radiotracer experiments showing that variations in Lp(a) plasma concentrations are due to differences in production not catabolism. When parameters were estimated tiwce in a subgroup of eight patients, satisfactory reproducibility was observed in six patients. Although parameters determined on two occasions correlated well, only FCR was concordant (intraclass correiation coefficient). Thus, despite the limitations arising from the assumptions implicit to this method, metabolic parameters of Lp(a) can be estimated from the rebound of plasma concentration following apheresis. Parts of this study were presented at the meeting of the International Atherosclerosis Society, Paris, October 5–9, 1997.     

Interaction of self‐nucleation and the addition of a nucleating agent on the crystallization behavior of isotactic polypropylene

The relationship between heterogeneous or homogeneous nucleation and self‐nucleation of polypropylene (PP) and PP nucleated by an organic phosphate salt (PPA) was studied by DSC. For pure PP, it homogeneously nucleated during cooling after melting at the selected temperature (T_s) of 170–200°C for 3 min, but at the T_s of 160–168°C self‐nucleation occurred; PPA only nucleated heterogeneously at the T_s of 168–200°C, and there existed self nucleation at the T_s of 160–168°C. The double melting peaks of PP and PPA at the T_s of 162°C were observed. Once the self‐nucleation occurred, the change of the crystallization temperature and heat of fusion of PP is more significant than that of PPA with the change of the T_s, depending upon the crystallization conditions. Results were explained by homogeneous nucleation, heterogeneous nucleation, self‐nucleation, and annealing crystallization. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 78–84, 2001     

Fluctuating water table effect on phosphorus release and availability from a Florida Spodosol

Spodosols in Florida exhibit a unique hydrology including a fluctuating water table that can often reach the surface horizon during the summer months. This paper evaluated the effects of fluctuating water table on P fluxes and availability in a typical Florida Spodosol. The study was conducted on an established bahiagrass (Paspalum notatum Flügge) pasture grown on a Smyrna sand (sandy, siliceous, hyperthermic Aeric Alaquods). Phosphorus fluxes were measured using suction cup lysimeters installed at depths of 15, 30, 60, 90, and 150 cm. The 15- and 30-cm deep lysimeters were located above the spodic (Bh) horizon, whereas the remaining lysimeters (60-, 90- and 150-cm) were below the Bh horizon. A pressure transducer was installed at the center of the experimental site to monitor changes in water table depth. Two anion exchange membranes (2 × 6 cm) were buried in each plot at a 15-cm depth to estimate in situ P availability. During the 2-year study, leachate P concentrations in the lysimeters above the Bh horizon increased as water tables rose in the months of August and September. Conversely, P concentration measured in the lysimeters below the Bh horizon remained relatively constant (0.02 mg L⁻¹). Soil P availability also increased (from 3.2 μg cm⁻² in June to 9.2 μg cm⁻² in August) in response to rising water table. Results showed that the fluctuating water table conditions experienced during the summer months in Florida cause upward flux of P from the Bh horizon, which increased soil P availability and susceptibility to off-site transport.     

Influence of poly(phosphoric acid) on the properties and structure of ethylene–vinyl acetate‐modified bitumen

Ethylene–vinyl acetate (EVA) modified (EM) bitumen was modified further by the addition of poly(phosphoric acid) (PPA). Owing to the gelation and acidification effect of PPA, the high‐temperature properties and compatibility of EM bitumen were improved greatly. Part dissolution of EVA after acidification was confirmed by the viscous behavior of EVA/PPA‐modified (EPM) bitumen in rheological tests to some extent. Morphology observation illustrated the decomposition of EVA in bitumen after PPA modification and ageing. Fourier transform infrared analysis proved that the hydrolysis reaction took place between the vinyl acetate segment of EVA molecule and the extra hydrogen protons of PPA. Thermal analysis displayed the thermodynamic behaviors of EM and EPM bitumens before and after ageing and confirmed the part dissolution of EVA further after PPA acidification. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46553.     

<Emphasis Type="SmallCaps">l</Emphasis>-Carnitine/Simvastatin Reduces Lipoprotein (a) Levels Compared with Simvastatin Monotherapy: A Randomized Double-Blind Placebo-Controlled Study

Lipoprotein (a) [Lp(a)] is an independent risk factor for cardiovascular disease. There are currently limited therapeutic options to lower Lp(a) levels. l ‐Carnitine has been reported to reduce Lp(a) levels. The aim of this study was to compare the effect of l ‐carnitine/simvastatin co‐administration with that of simvastatin monotherapy on Lp(a) levels in subjects with mixed hyperlipidemia and elevated Lp(a) concentration. Subjects with levels of low‐density lipoprotein cholesterol (LDL‐C) >160 mg/dL, triacylglycerol (TAG) >150 mg/dL and Lp(a) >20 mg/dL were included in this study. Subjects were randomly allocated to receive l ‐carnitine 2 g/day plus simvastatin 20 mg/day (N = 29) or placebo plus simvastatin 20 mg/day (N = 29) for a total of 12 weeks. Lp(a) was significantly reduced in the l ‐carnitine/simvastatin group [?19.4%, from 52 (20–171) to 42 (15–102) mg/dL; p = 0.01], but not in the placebo/simvastatin group [?6.7%, from 56 (26–108) to 52 (27–93) mg/dL, p = NS versus baseline and p = 0.016 for the comparison between groups]. Similar significant reductions in total cholesterol, LDL‐C, apolipoprotein (apo) B and TAG were observed in both groups. Co‐administration of l ‐carnitine with simvastatin was associated with a significant, albeit modest, reduction in Lp(a) compared with simvastatin monotherapy in subjects with mixed hyperlipidemia and elevated baseline Lp(a) levels.