Prognostic Value of Red Blood Cell Distribution Width on Bleeding Events in Nonvalvular Atrial Fibrillation Patients Taking Dabigatran (110 mg b.i.d.) after Catheter Ablation.

OBJECTIVES: Recent research has indicated that red blood cell distribution width (RDW) is associated with the prognosis of cardiovascular diseases such as chronic heart failure and coronary heart disease. We aimed to study the predictive value of RDW for bleeding events in patients with nonvalvular atrial fibrillation (NVAF) during the administration of 110 mg of dabigatran twice a day after catheter ablation. METHODS: One hundred and seventy-two NVAF patients who were hospitalized and received catheter ablation in Jiangsu Provincial People's Hospital from January 2014 to January 2015 were enrolled (110 mg of dabigatran was administered orally to outpatients preoperatively twice a day for 3 weeks). The enrolled patients were divided into the high RDW (>12.8%) group (n = 85) and the low RDW (≤12.8%) group (n = 87) according to the median RDW. The activated partial thromboplastin time (APTT) at dabigatran trough concentration was also detected. Patients were followed up for 3 months to observe the occurrence of bleeding events, and the predictive value of RDW as well as APTT for bleeding events was assessed from receiver-operating characteristic (ROC) analyses. RESULTS: In all patients, preoperatively, no bleeding events were observed and the APTT did not exceed twice the normal upper limit. Thirteen cases of bleeding events, all minor bleeding, occurred after a 3-month follow-up: 3 of gingival bleeding, 3 of urinary tract bleeding, 3 conjunctival hemorrhages and 4 subcutaneous hemorrhages. The incidence of bleeding events in the low RDW group was lower than in the high RDW group (3.4 vs. 11.8%, p = 0.039). The areas under the ROC curve for RDW and APTT to predict the occurrence of bleeding events were 0.737 (cutoff point 13.25%; p < 0.05) and 0.558 (p > 0.05), respectively. CONCLUSION: RDW was associated with the occurrence of bleeding events in NVAF patients on dabigatran (110 mg twice a day) after ablation, while also being an independent predictor of bleeding events. RDW had superior predictive value for bleeding events over APTT when APTT did not exceed twice the normal upper limit.

Collision-attachment simulation of membrane fouling by oppositely and similarly charged colloids.

The fouling propensity of oppositely charged colloids (OCC) and similarly charged colloids (SCC) on reverse osmosis (RO) and nanofiltration (NF) membranes are systematically investigated using a developed collision-attachment approach. The probability of successful colloidal attachment (i.e., attachment efficiency) is modelled by Boltzmann energy distribution, which captures the critical roles of colloid-colloid/membrane interaction and permeate drag. Our simulations highlight the important effects of ionic strength Is, colloidal size dp and initial flux J0 on combined fouling. In a moderate condition (e.g., Is =10 mM, dp=50 nm and J0= 100 L/m2h), OCC mixtures shows more severe fouling compared to the respective single foulant owing to electrostatic neutralization. In contrast, the flux loss of SCC species falls between those of the two single foulants but more closely resembles that of the single low-charged colloids due to its weak electrostatic repulsion. Increased ionic strength Is leads to less severe fouling for OCC but more severe fouling for SCC, as a result of the suppressed electrostatic attraction/repulsion. At a high Is (e.g., 3-5 M), all the single and mixed systems show the identical pseudo-stable flux Js. Small colloidal size leads to the drag-controlled condition, where severe fouling occurs for both single and mixed foulants. On the contrary, better flux stability appears at greater dp for both individual and mixed species, thanks to the increasingly dominated role of energy barrier and thus lowered attachment efficiency. Furthermore, higher J0 above limiting flux exerts greater permeate drag, leading to elevated attachment efficiency, and thus more flux losses for both OCC and SCC. Our modelling gains deep insights into the role of energy barrier, permeate drag, and attachment efficiency in governing combined fouling, which provides crucial guidelines for fouling reduction in practical engineering.

Relating critical and limiting fluxes to metastable and long-term stable fluxes in colloidal membrane filtration through collision-attachment theory.

In membrane technology for water/wastewater treatment, the concepts of critical flux (JC) and limiting flux (JL) suggest the existence of a threshold flux below which no fouling occurs. However, their important roles on stable flux duration have not been sufficiently understood. This work adopts a collision-attachment approach to clarify the relationship of JC, JL to metastable (i.e., short-term stable) and long-term stable fluxes based on their dependence on initial flux (J0), foulant-clean-membrane energy barrier (Ef-m), and foulant-fouled-membrane energy barrier (Ef-f). When J0 is below JL, water flux remains stable over a long time even for the case of J0 over JC, thanks to the strongly repulsive Ef-f. At J0 > JL and J0 > JC, the water flux is unstable at the beginning of filtration, and the flux ultimately decreases to JL as the long-term stable flux. Under the condition of JL < J0 ≤ JC, an initial metastable flux appears owing to the high Ef-m, with longer metastable period observed at lower J0 and for more hydrophilic/charged membrane or colloids. Nevertheless, rapid flux decline occurs subsequently due to the energy barrier shifting to weak Ef-f, and the water flux eventually degenerates to JL in long-term fouling duration. Our results provide significant guidelines for fouling control strategies with respect to membrane design, feedwater pretreatment, and operational optimization.

Insights into the roles of membrane pore size and feed foulant concentration in ultrafiltration membrane fouling based on collision-attachment theory.

Membrane property and feed characteristics play critical roles in membrane fouling. This paper aims to clarify the roles of membrane pore size (φ) and feed foulant concentration (Cb ) in ultrafiltration fouling induced by polysaccharides. The fouling behaviors were expounded by collision-attachment theory, where the rate of membrane fouling is mainly determined by collision frequency (JCb ) and attachment efficiency (γ). At the initial fouling stage, rapid flux decline was observed at large φ or high Cb due to the great JCb and/or γ. At the later fouling stage, there existed a nearly identical maximum stable flux attributing to the same JCb and γ, which was independent of φ and Cb . Moreover, the smaller φ can lead to less foulants passed through the membrane and thus more foulants attaching on the membrane, while the higher Cb can give rise to more foulants on both the membrane surface and in the permeate. The results presented in current study provide fundamental basis in understanding membrane fouling. PRACTITIONER POINTS: Collision-attachment theory was employed to expound the UF fouling behavior. Rapid flux decline occurred at large membrane pore size or high feed foulant concentration in the initial fouling stage. Membranes with different pore size or feed foulant concentration had an identical flux at the latter fouling stage. Lowering membrane pore size or increasing feed foulant concentration can lead to more foulants attaching on the membrane surface.

Two cadmium(II) coordination polymers as multi-functional luminescent sensors for the detection of Cr(VI) anions, dichloronitroaniline pesticide, and nitrofuran antibiotic in aqueous media.

Two ternary cadmium(II) coordination polymers, with the formulas being {[Cd(tptc)0.5(bpz)(H2O)]·0.5H2O}n (CP 1), and [Cd(tptc)0.5(bpy)]n (CP 2), were designed through mixed ligands strategy. Benefiting from the excellent chemical stability and luminescent property, two Cd(II) CPs possessing efficient multi-functional fluorescent responses toward Cr(VI) anions, 2,6-dichloro-4-nitroaniline pesticide, and nitrofuran antibiotic in aqueous media with high sensitivity, selectivity, and excellent recyclable behaviors with the detection limits (LODs) are 235 ppb for CrO42- anion, 343 ppb for Cr2O72- anion, 112 ppb for DCN pesticide, 62 ppb for NFT antibiotic for CP 1, and 173 ppb for CrO42- anion, 270 ppb for Cr2O72- anion, 638 ppb for DCN pesticide, 184 ppb for NFT antibiotic for CP 2, respectively. Besides, the mechanisms of luminescence quenching were revealed from the viewpoint of internal filter effect (IFE) and photoinduced electron transfer (PET).

Performance and autopsy of nanofiltration membranes at an oil-field wastewater desalination plant.

In this study, the long-term operational performance of an on-site NF facility at a full-scale oil-field wastewater desalination plant was monitored. The NF facility with poor permeability due to membrane fouling enables efficient multivalent salt removal (rejections of Mg2+, Ca2+, Fe3+, and Al3+ were approximately 100%). Moreover, a comparison of the cleaning efficiencies of two on-site cleaning modes indicated that PL-007 cleaning helped to improve the effectiveness of subsequent acid cleaning in the removal of inorganic foulants. Furthermore, a spiral-wound NF membrane module harvested from the plant was unfolded and autopsied. The results showed that both anionic polyacrylamide (APAM) and crude oil were identified as the predominant organic matter on the membrane surface and collectively accounted for a substantial fraction (86.3%) in terms of dry weight. Additionally, dissolved organics with a high molecular weight were prone to accumulation on the membrane surface. Multivalent elements, including Mg, Ca, Al, Fe, and Si, were the primary inorganic species in the fouling layer. Among the inorganic elements, Si occupied a high proportion and existed in the form of SiO2 in the fouling layer. According to the autopsy results, organic fouling combined with inorganics was responsible for the decline in the flux.

Molecularly imprinted polymer decorated nanoporous gold for highly selective and sensitive electrochemical sensors.

Electrochemical nanosensors based on nanoporous gold leaf (NPGL) and molecularly imprinted polymer (MIP) are developed for pharmaceutical analysis by using metronidazole (MNZ) as a model analyte. NPGL, serving as the loading platform for MIP immobilization, possesses large accessible surface area with superb electric conductivity, while electrochemically synthesized MIP thin layer affords selectivity for specific recognition of MNZ molecules. For MNZ determination, the hybrid electrode shows two dynamic linear range of 5 × 10(-11) to 1 × 10(-9) mol L(-1) and 1 × 10(-9) to 1.4 × 10(-6) mol L(-1) with a remarkably low detection limit of 1.8 × 10(-11) mol L(-1) (S/N = 3). In addition, the sensor exhibits high binding affinity and selectivity towards MNZ with excellent reproducibility and stability. Finally, the reliability of MIP-NPGL for MNZ detection is proved in real fish tissue samples, demonstrating the potential for the proposed electrochemical sensors in monitoring drug and biological samples.