Heart Sound Biometric System Based on Marginal Spectrum Analysis

sensor

Bio-Inspired Polymeric Structures with Special Wettability and Their Applications: An Overview

It is not unusual for humans to be inspired by natural phenomena to develop new advanced materials; such materials are called bio-inspired materials. Interest in bio-inspired polymeric superhydrophilic, superhydrophobic, and superoleophobic materials has substantially increased over the last few decades, as has improvement in the related technologies. This review reports the latest developments in bio-inspired polymeric structures with desired wettability that have occurred by mimicking the structures of lotus leaf, rose petals, and the wings and shells of various creatures. The intrinsic role of surface chemistry and structure on delivering superhydrophilicity, superhydrophobicity, and superoleophobicity has been extensively explored. Typical polymers, commonly used structures, and techniques involved in developing bio-inspired surfaces with desired wettability are discussed. Additionally, the latest applications of bio-inspired structures with desired wettability in human activities are also introduced

Correction: Mao et al. Controllable Construction of IrCo Nanoclusters and the Performance for Water Electrolysis. <i>Catalysts</i> 2022, <i>12</i>, 914

The authors wish to make the following corrections to this paper [...

Preoperative P-wave duration as a predictor of atrial fibrillation after coronary artery bypass grafting: A prospective cohort study with meta-analysis

Objectives: Reported prediction rules for postoperative atrial fibrillation (AF) have suffered from inconsistent results and controversy surrounding the predictive value of a preoperative P-wave duration (PreOPWD). This study examined PreOPWD as a predictor for AF after coronary artery bypass grafting (CABG). Methods: Two-hundred-and-ninety-nine patients with sinus rhythm before off-pump CABG were recruited into the study. Patients' demographic and clinical data were evaluated prospectively. Patients were continuously monitored for the first seven postoperative days. Multiple logistic regression was used to determine significant predictors of AF. Findings were then combined with similar studies and a meta-analysis was performed. Results: Postoperative AF was observed in 33.1% of 299 patients. Patients with AF were older, had a prolonged PreOPWD, higher incidences of hypertension, aortic regurgitation, and mitral regurgitation. A cut-off point of PreOPWD≥105 ms achieved a specificity of 74%, and a sensitivity of 65% for predictive of AF. Multivariate analysis showed that PreOPWD≥105 ms (odds ratio [OR] 4.63, 95% confidence intervals [CI] 2.66 to 8.03, P < 0.001), age≥60 years (OR 2.72, 95% CI 1.51 to 4.90, P < 0.01) and hypertension (OR 2.10, 95% CI 1.08 to 4.07, P < 0.05) independently predicted postoperative AF. A meta-analysis of this data combined with those of ten other studies showed that PreOPWD was greater in patients with POAF, with a weighted mean difference of 3.95 ms (95% CI 1.97 to 5.92, P < 0.001). Conclusion: This study confirmed, among other predictive characteristics, that PreOPWD is a powerful independent predictor of POAF. Keywords: Atrial fibrillation, Coronary artery bypass, Off-pump, Cohort studies, Meta-analysi

Enhanced Li+ adsorption by magnetically recyclable iron-doped lithium manganese oxide ion-sieve: Synthesis, characterization, adsorption kinetics and isotherm

The Li+ adsorption from aqueous solution by lithium-ion sieve has become one of the most promising methods due to the high efficiency and selectivity towards lithium ion (Li+). However, the industrial application of manganese oxide ion-sieve is limited due to its difficult separation and decrease of adsorption capacity resulting from manganese dissolution loss. In this paper, the magnetically recyclable Fe-doped manganese oxide lithium ion-sieves with spinel-structure were proposed and prepared from LiMn2-xFexO4 synthesized by solid state reaction method. The effects of calcination temperature, calcination time and Fe doping amounts on the phase compositions, dissolution loss and adsorption performance of lithium ion-sieve precursors were systematically studied, and the influences of solution pH value, initial Li+ concentration and adsorption temperature on the adsorption performance were investigated. The adsorption mechanism was further discovered through adsorption kinetics and thermodynamics. The results show that the adsorption capacity of lithium ion-sieves could reach to 34.8 mg·g–1 when the calcination temperature, time and Fe doping content were controlled at 450 °C, 6 h, and 0.05, respectively. The Mn dissolution loss was reduced to 0.51%, much lower than the undoped lithium ion-sieve (2.48%), which is attributed to the inhibition of disproportionation reaction with the increasing proportion of Mn4+ in the skeleton. The adsorption process conformed to the pseudo-second-order kinetics equation and Langmuir isothermal adsorption model. Furthermore, the recycling performance of Fe-doped lithium ion-sieve showed that the adsorption capacity could remain 22.5 mg·g–1 (about 70%) after five cycles, which is greater than that of undoped lithium ion-sieve (about 50%), and the recovery of lithium ion-sieve can be realized by magnetic separation in an applying magnetic field

A stepwise separation process for selective recovery of gallium from hydrochloric acid leach liquor of coal fly ash

The interest in gallium (Ga) recovery from coal fly ash has been driven by its rapidly growing demand for manufacturing and its extraction can facilitate the effective use of coal fly ash, which is conducive to reducing the soil degradation and environment danger. In this study, polyurethane foam (PUF) as an adsorbent for Ga(III) recovery was found to exhibit a good structural stability and a high selectivity in a strongly acidic solution. Adsorption measurements show that PUF has a good adsorption ability and its maximum adsorption capacity is 62.53 mg/g. Furthermore, its adsorption behavior can be described well by the pseudo-second-order model. The concentrations of Cl(I) played the key role in the adsorption. Meanwhile, the co-existed Fe(III) in the coal fly ash hydrochloric acid leach liquor (CFAHL) exhibits significant interference to the selective adsorption of Ga(III). Therefore, a stepwise process involving Fe(III) removal and Ga(III) adsorption is proposed for the recovery Ga from CFAHL. At an equilibrium pH of 0, the Fe(III) in the CFAHL can be removed by 1 mol/L P507. Then, the Ga (III) can be quantitatively adsorbed from the CFAHL using PUF with limited co-adsorption of Al(III), Mg(II), and Ca(II). The adsorption capacity of Ga(III) remains steady after PUF is used for more than 10 cycles. Based on the results of IR, XPS and DFT, it is speculated that the Ga(III) is probably coordinated in the form of GaCl3 with the donor O atoms of the urethane group (?NHCOO?) on the PUF surface. The overall results demonstrate the potential use of PUF for Ga recovery from acidic solutions

Separating NaCl and AlCl3·6H2O Crystals from Acidic Solution Assisted by the Non-Equilibrium Phase Diagram of AlCl3-NaCl-H2O(-HCl) Salt-Water System at 353.15 K

Extracting AlCl3·6H2O from acid leaching solution through crystallization is one of the key processes to extracting aluminum from fly ash, coal gangue and other industrial solid wastes. However, the obtained products usually have low purity and a key problem is the lack of accurate data for phase equilibrium. This paper presented the non-equilibrium phase diagrams of AlCl3-NaCl-H2O (HCl) salt-water systems under continuous heating and evaporation conditions, which were the main components of the acid leaching solution obtained through a sodium-assisted activation hydrochloric acid leaching process. The ternary system was of a simple eutonic type under different acidities. There were three crystalline regions; the crystalline regions of AlCl3·6H2O, NaCl and the mixture AlCl3·6H2O/NaCl, respectively. The phase diagram was used to optimize the crystallization process of AlCl3·6H2O and NaCl. A process was designed to evaporate and remove NaCl at the first stage of the evaporation process, and then continue to evaporate and crystallize AlCl3·6H2O after solid-liquid separation. The purities of the final salt products were 99.12% for NaCl and up to 97.35% for AlCl3·6H2O, respectively