Biofouling is a major disruptive process affecting the fuel efficiency and durability of maritime vessel coatings. Previous research has shown that amphiphilic coatings consisting of a siloxane backbone functionalized with hydrophilic moieties are effective marine antifouling and fouling-release materials. Poly(ethylene glycol) (PEG) has been the primary hydrophilic component used in such systems.
View Article and Find Full Text PDFAmphiphilic polymer coatings combining hydrophilic elements, in particular zwitterionic groups, and hydrophobic elements comprise a promising strategy to decrease biofouling. However, the influence of the content of the hydrophobic component in zwitterionic coatings on the interfacial molecular reorganization dynamics and the anti-fouling performance is not well understood. Therefore, coatings of amphiphilic copolymers of sulfobetaine methacrylate 3-[N-2'-(methacryloyloxy)ethyl-N,N-dimethyl]-ammonio propane-1-sulfonate (SPE) are prepared which contain increasing amounts of hydrophobic n-butyl methacrylate (BMA).
View Article and Find Full Text PDFThe buildup of organic matter and organisms on surfaces exposed to marine environments, known as biofouling, is a disruptive and costly process affecting maritime operations. Previous research has identified some of the surface characteristics particularly suited to the creation of antifouling and fouling-release surfaces, but there remains room for improvement against both macrofouling and microfouling organisms. Characterization of their adhesives has shown that many rely on oxidative chemistries.
View Article and Find Full Text PDFPolysaccharide multilayers consisting of hyaluronic acid and chitosan were prepared by layer-by-layer assembly. To be used in seawater, the multilayers were crosslinked to a different degree using thermal or chemical methods. ATR-FTIR revealed different amide densities as a result of the crosslinking conditions.
View Article and Find Full Text PDFWhile zwitterionic interfaces are known for their excellent low-fouling properties, the underlying molecular principles are still under debate. In particular, the role of the zwitterion orientation at the interface has been discussed recently. For elucidation of the effect of this parameter, self-assembled monolayers (SAMs) on gold were prepared from stoichiometric mixtures of oppositely charged alkyl thiols bearing either a quaternary ammonium or a carboxylate moiety.
View Article and Find Full Text PDFDendritic polyglycerols (PGs) were synthesized and postmodified by grafting of poly(ethylene glycol) (PEG) and polypropylene glycol (PPG) diglycidyl ether groups, and their antifouling and fouling-release properties were tested. Coating characterization by spectroscopic ellipsometry, contact angle goniometry, attenuated total internal reflection-Fourier transform infrared spectroscopy (ATR-FTIR), and atomic force microscopy showed brushlike morphologies with a high degree of microscale roughness and the ability to absorb large amounts of water within seconds. PGs with three different thicknesses were tested in laboratory assays against settlement of larvae of the barnacle and against the settlement and removal of zoospores of the alga .
View Article and Find Full Text PDFPolyelectrolyte multilayers (PEMs) consisting of hyaluronic acid (HA) and chitosan (Ch) are extensively studied for biomedical applications and suppress bacterial and protein attachment. Here, we prepared and tested HA/Ch PEMs as marine fouling-release coatings. PEMs were constructed by layer-by-layer assembly using spin coating.
View Article and Find Full Text PDFBackground: Biological adhesion (bioadhesion), enables organisms to attach to surfaces as well as to a range of other targets. Bioadhesion evolved numerous times independently and is ubiquitous throughout the kingdoms of life. To date, investigations have focussed on various taxa of animals, plants and bacteria, but the fundamental processes underlying bioadhesion and the degree of conservation in different biological systems remain poorly understood.
View Article and Find Full Text PDFBACKGROUND: Total cholesterol was among the earliest identified risk factors for coronary heart disease (CHD). We sought to identify genetic variants in six genes associated with lipid metabolism and estimate their respective contribution to risk for CHD. METHODS: For 6 lipid-associated genes (LCAT, CETP, LIPC, LPL, SCARB1, and ApoF) we scanned exons, 5' and 3' untranslated regions, and donor and acceptor splice sites for variants using Hi-Res Melting® curve analysis (HRMCA) with confirmation by cycle sequencing.
View Article and Find Full Text PDFObjective: The aim of this study is to discover common variants in 6 lipid metabolic genes and construct and validate a genetic risk score (GRS) based on the joint effects of genetic variants in multiple genes from lipid and other pathobiologic pathways.
Background: Explaining the genetic basis of coronary artery disease (CAD) is incomplete. Discovery and aggregation of genetic variants from multiple pathways may advance this objective.
Objectives: The objective of this study was to identify associations of the cholesteryl ester transfer protein (CETP) gene with coronary artery disease (CAD) with tagging (t) single nucleotide polymorphisms (SNPs) chosen to optimally account for intra-genic variation.
Background: The CETP gene plays a critical role in lipoprotein metabolism, but the common and well-studied TaqIB variant is inconsistently predictive of CAD.
Methods: From a deoxyribonucleic acid bank of 10,020 individuals, nondiabetic nonsmoking patients (n = 4,811) with angiographically defined, clinically significant CAD (> or =70% stenosis) or normal coronaries were genotyped for 11 CETP tSNPs.
J Thromb Thrombolysis
December 2006
Background: Warfarin has a narrow therapeutic range and wide inter-individual dosing requirements that may be related to functional variants of genes affecting warfarin metabolism (i.e., CYP2C9) and activity (i.
View Article and Find Full Text PDFBackground: Whereas C-reactive protein (CRP) is a nonspecific marker of coronary artery disease (CAD) and cardiovascular (CV) events, Lp-PLA2 may be a nonvariable inflammatory biomarker. We evaluated the independent association of lipoprotein-associated phospholipase A2 (Lp-PLA2) to angiographic CAD and CV events adjusting for standard factors, lipids, and CRP.
Methods: Lipoprotein-associated phospholipase A2 (PLAC test, diaDexus, Inc, San Francisco, CA) and CRP were measured from samples donated by consecutive consenting patients (N = 1493) enrolled in the registry of the Intermountain Heart Collaborative Study.
Ann Hum Genet
July 2006
Full characterization of intragenic variation may improve candidate gene associations. This study selected tagging (t) single nucleotide polymorphisms (SNPs) to comprehensively represent genetic variability in the cholesteryl ester transfer protein (CETP) gene. Nineteen SNPs were identified in 50 unrelated individuals in the SNP discovery phase, and 13 intronic SNPs were added from the literature.
View Article and Find Full Text PDFA medium-sensitivity assay for C-reactive protein (CRP) was compared with a high-sensitivity, enhanced immunoturbidimetric assay in 803 angiographically studied patients. Different absolute CRP values were found by the assays, but there was a high correlation by quartile rank and similar predictive values for death and myocardial infarction. This suggests that the conclusions of previous studies performed using the medium-sensitivity assay are still valid but that cross-study comparisons should use percentile rank.
View Article and Find Full Text PDF