Contemporary survival and anticoagulation of patients with atrial fibrillation: A community based cohort study in China

BackgroundsThe understanding of death in patients with atrial fibrillation (AF) in China is limited. This study aimed to assess the contemporary survival of AF patients in China and to explore risk factors for deaths.MethodsThis was a prospective community-based cohort study including 559 AF patients, who were followed-up from July 2015 to December 2020.ResultsDuring 66-month follow-up, there were 200 deaths (56.5% cardiovascular, 40.0% non-cardiovascular, and 3.5% unknown causes) among 559 AF patients with the median age of 76 years. The top three causes of death were heart failure (33.0%), ischemic stroke (17.0%) and cancer (16.5%). Multivariate Cox regression analysis indicated baseline variables positively associated with all-cause death were age (HR: 1.10, 95% CI: 1.08–1.13), AF subtype (HR: 1.37, 95% CI: 1.08–1.73), prior myocardial infarction (HR: 3.40, 95% CI: 1.48–7.78), previous tumor (HR: 2.61, 95% CI: 1.37–4.98), hypoglycemic therapy at baseline (HR: 1.81, 95% CI: 1.13–2.91), but body weight (HR: 0.98, 95% CI: 0.97–1.00) and use of calcium channel blocker (CCB) (HR: 0.62, 95% CI: 0.41–0.95) played a protective role to all-cause death. Of patients who were alive at the end of follow-up, 24.0% were on oral anticoagulants (OAC) alone, 4.5% on dual antithrombotic therapy, 33.1% on antiplatelet agents alone and 38.4% weren't on any antithrombotic medication.ConclusionIschemic stroke still remains one of the leading causes of death and OAC is seriously underused in AF patients in China. Independent risk factors for death are age, AF subtype, previous tumor, prior myocardial infarction, hypoglycemic therapy, low body weight and no CCB use.Clinical Trial Registrationhttp://www.chictr.org.cn/ (ChiCTR-ICR-15007036)

Probing nanomechanics of cation -interractions in aqueous solution

2

The impact of cellulose nanocrystals on the aggregation and initial adhesion of Pseudomonas fluorescens bacteria

Deposition on silica surfaces of two Pseudomonas fluorescens strains (CHA0 and CHA19-WS) having different extracellular polymeric substance (EPS) producing capacities was studied in the absence and presence of cellulose nanocrystals (CNCs). Batch (batch soaking) and continuous flow (quartz crystal microbalance with dissipation) methods were used to evaluate the impact of CNCs on bacterial initial adhesion. This study demonstrated that bacterial initial adhesion to solid surfaces can be significantly hindered by CNCs using both methods. In the presence of CNCs, it was observed that bacteria with more EPS aggregated more significantly compared to bacteria with less EPS, and that bacterial deposition under this condition decreased to a greater extent. The classic DLVO theory failed to predict bacterial adhesion behavior in this study. A detailed discussion is provided regarding potential antibacterial adhesion mechanisms of CNCs.</p

Molecular interactions of mussel protective coating protein, mcfp-1, from Mytilus californianus

Protective coating of the byssus of mussels (Mytilus sp.) has been suggested as a new paradigm of medical coating due to its high extensibility and hardness co-existence without their mutual detriment. The only known biomacromolecule in the extensible and tough coating on the byssus is mussel foot protein-1 (mfp-1), which is made up with positively charged residues (similar to 20 mol%) and lack of negatively charged residues. Here, adhesion and molecular interaction mechanisms of Mytilus californianus foot protein-1 (mcfp-1) from California blue mussel were investigated using a surface forces apparatus (SFA) in buffer solutions of different ionic concentrations (0.2-0.7 M) and pHs (3.0-5.5). Strong and reversible cohesion between opposed positively charged mcfp-1 films was measured in 0.1 M sodium acetate buffer with 0.1 M KNO3. Cohesion of mcfp-1 was gradually reduced with increasing the ionic strength, but was not changed with pH variations. Oxidation of 3,4-dihydroxyphenylalanine (DOPA) residues of mcfp-1, a key residue for adhesive and coating proteins of mussel, didn&apos;t change the cohesion strength of mcfp-1 films, but the addition of chemicals with aromatic groups (i.e., aspirin and 4-methylcatechol) increased the cohesion. These results suggest that the cohesion of mcfp-1 films is mainly mediated by cation-it interactions between the positively charged residues and benzene rings of DOPA and other aromatic amino acids (similar to 20 mol% of total amino acids of mcfp-1), and pi-pi interactions between the phenyl groups in mcfp-1. The adhesion mechanism obtained for the mcfp-1 proteins provides important insight into the design and development of functional biomaterials and coatings mimicking the extensible and robust mussel cuticle coating. (C) 2011 Elsevier Ltd. All rights reserved.X1146Nsciescopu

The impact of cellulose nanocrystals on the aggregation and initial adhesion of Pseudomonas fluorescens bacteria

Deposition on silica surfaces of two Pseudomonas fluorescens strains (CHA0 and CHA19-WS) having different extracellular polymeric substance (EPS) producing capacities was studied in the absence and presence of cellulose nanocrystals (CNCs). Batch (batch soaking) and continuous flow (quartz crystal microbalance with dissipation) methods were used to evaluate the impact of CNCs on bacterial initial adhesion. This study demonstrated that bacterial initial adhesion to solid surfaces can be significantly hindered by CNCs using both methods. In the presence of CNCs, it was observed that bacteria with more EPS aggregated more significantly compared to bacteria with less EPS, and that bacterial deposition under this condition decreased to a greater extent. The classic DLVO theory failed to predict bacterial adhesion behavior in this study. A detailed discussion is provided regarding potential antibacterial adhesion mechanisms of CNCs.Peer reviewed: YesNRC publication: Ye

The effects of biofilm on the transport of stabilized zerovalent iron nanoparticles in saturated porous media

The transport of stabilized zerovalent iron nanoparticles (nZVI) has recently been the topic of extensive research due to its proven potential as an in situ remediation tool. However, these studies have ignored the effects of biofilms-complex aggregations of bacterial cells and excreted extracellular polymeric substances present in nearly all aquatic systems-on the transport of these particles. This study examines the effects of Pseudomonas aeruginosa (PAO1) biofilm, at a cell concentration similar to that reported for saturated aquifers, on the transport of commercially available, poly (acrylic acid) stabilized nZVI (pnZVI) in 14cm long columns packed with saturated glass beads at salt concentrations of 1 and 25mM NaCl. Compared to retention on uncoated columns, in the presence of biofilm the retention of pnZVI increased at higher ionic strength, while ionic strength played no role in retention of these nanoparticles in the absence of biofilm. The Tufenkji-Elimelech correlation equation predicts lower retention of pnZVI on biofilm coated columns compared to uncoated columns due to a lower Hamaker constant, and DLVO energy considerations predict the most favorable attachment to uncoated porous media at higher ionic strength. A steric (polymer-mediated) model that considers the combined influence of steric effects of polymers and DLVO interactions is shown to adequately describe particle retention in columns.</p

Molecular interactions of mussel protective coating protein, mcfp-1, from Mytilus californianus

Protective coating of the byssus of mussels (Mytilus sp.) has been suggested as a new paradigm of medical coating due to its high extensibility and hardness co-existence without their mutual detriment. The only known biomacromolecule in the extensible and tough coating on the byssus is mussel foot protein-1 (mfp-1), which is made up with positively charged residues (~20 mol%) and lack of negatively charged residues. Here, adhesion and molecular interaction mechanisms of Mytilus californianus foot protein-1 (mcfp-1) from California blue mussel were investigated using a surface forces apparatus (SFA) in buffer solutions of different ionic concentrations (0.2-0.7 M) and pHs (3.0-5.5). Strong and reversible cohesion between opposed positively charged mcfp-1 films was measured in 0.1 M sodium acetate buffer with 0.1 M KNO 3. Cohesion of mcfp-1 was gradually reduced with increasing the ionic strength, but was not changed with pH variations. Oxidation of 3,4-dihydroxyphenylalanine (DOPA) residues of mcfp-1, a key residue for adhesive and coating proteins of mussel, didn't change the cohesion strength of mcfp-1 films, but the addition of chemicals with aromatic groups (i.e., aspirin and 4-methylcatechol) increased the cohesion. These results suggest that the cohesion of mcfp-1 films is mainly mediated by cation-π interactions between the positively charged residues and benzene rings of DOPA and other aromatic amino acids (~20 mol% of total amino acids of mcfp-1), and π-π interactions between the phenyl groups in mcfp-1. The adhesion mechanism obtained for the mcfp-1 proteins provides important insight into the design and development of functional biomaterials and coatings mimicking the extensible and robust mussel cuticle coating.</p

Understanding the molecular interactions of lipopolysaccharides during E. coli initial adhesion with a surface forces apparatus

Lipopolysaccharides (LPS) occupy 75% of the surface of Gram-negative bacteria. This work investigates the role of LPS during bacterial adhesion to solid substrates. Two model lipopolysaccharides, LPS1 and LPS2, were examined. LPS1 from E. coli JM109 has a full LPS chain consisting of lipid A, core polysaccharides, and O-antigen; LPS2 from K12 has a truncated chain without the O-antigen portion. Interactions between an LPS layer prealigned on polystyrene (PS) and three different substrates (mica, PS-coated mica, and 3-aminopropyltriethoxysilane (APTES)-functionalized mica) in 0.1 M NaCl were measured using a surface forces apparatus (SFA). The PS-supported LPS showed strong adhesion to APTES, weak adhesion to mica, and strong repulsion to PS substrate. Electrostatic interaction and steric effects contribute significantly to the interactions between the LPS and different substrates. The presence of long O-antigen chains in LPS1 reduces bacterial adhesion to various substrates because of the presence of an energetic barrier during the adsorption process, which is caused by the affinity of hydrophilic neutral O-antigen chains to water and the steric entropic barrier of LPS chains on the cell membrane surface.</p