Adsorption and Desorption Properties of Polyethylenimine/Polyvinyl Chloride Cross-Linked Fiber for the Treatment of Azo Dye Reactive Yellow 2.

In this study, the optimal conditions for the fabrication of polyethylenimine/polyvinyl chloride cross-linked fiber (PEI/PVC-CF) were determined by comparing the adsorption capacity of synthesized PEI/PVC-CFs for Reactive Yellow 2 (RY2). The PEI/PVC-CF prepared through the optimal conditions was characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET) analyses. Several batch adsorption and desorption experiments were carried out to evaluate the sorption performance and reusability of PEI/PVC-CF for RY2. As a result, the adsorption of RY2 by PEI/PVC-CF was most effective at pH 2.0. A pseudo-second-order model fit better with the kinetics adsorption data. The adsorption isotherm process was described well by the Langmuir model, and the maximum dye uptake was predicted to be 820.6 mg/g at pH 2.0 and 25 °C. Thermodynamic analysis showed that the adsorption process was spontaneous and endothermic. In addition, 1.0 M NaHCO3 was an efficient eluent for the regeneration of RY2-loaded PEI/PVC-CF. Finally, the repeated adsorption-desorption experiments showed that the PEI/PVC-CF remained at high adsorption and desorption efficiencies for RY2, even in 17 cycles.

A reusable adsorbent polyethylenimine/polyvinyl chloride crosslinked fiber for Pd(II) recovery from acidic solutions.

In this study, a mixture of polyethylenimine (PEI) and polyvinyl chloride (PVC) was reacted at 80 °C for 6 h to synthesize crosslinked PEI/PVC polymer solution, which was injected to produce the PEI/PVC-crosslinked fiber (PEI/PVC-CF). PEI/PVC-CF was investigated as an adsorbent to remove and recover Pd(II) from acidic solutions. In order to examine the adsorption characteristics and usability of PEI/PVC-CF for Pd(II) recycling, several experiments such as isotherm, kinetics, desorption and reuse were conducted. The adsorption isotherms were fitted using the Langmuir and Freundlich models, respectively. The maximum adsorption capacity was estimated as 146.03 mg/g according to the Langmuir model. The kinetic experiments demonstrated that adsorbent reaches adsorption equilibrium within 60 min for initial Pd(II) concentrations of 25-100 mg/L. After adsorption, Pd(II) on PEI/PVC-CF was easily desorbed using acidified thiourea solution, and the desorption efficiency increased with the thiourea concentration. It was also demonstrated that PEI/PVC-CF can be used repeatedly for at least five cycles without reduction in adsorption capacity.

Material flow analysis-based assessment of polypropylene-fiber-containing microplastics released from disposable masks: Characterizing distribution in the environmental media.

With the upsurge in the use of disposable masks during the coronavirus disease pandemic, improper disposal of discarded masks and their negative impact on the environment have emerged as major issues. Improperly disposed of masks release various pollutants, particularly microplastic (MP) fibers, which can harm both terrestrial and aquatic ecosystems by interfering with the nutrient cycling, plant growth, and the health and reproductive success of organisms. This study assesses the environmental distribution of polypropylene (PP)-containing MPs, generated from disposable masks, using material flow analysis (MFA). The system flowchart is designed based on the processing efficiency of various compartments in the MFA model. The highest amount of MPs (99.7 %) is found in the landfill and soil compartments. A scenario analysis reveals that waste incineration significantly reduces the amount of MP transferred to landfills. Therefore, considering cogeneration and gradually increasing the incineration treatment rate are crucial to manage the processing load of waste incineration plants and minimize the negative impact of MPs on the environment. The findings provide insights into the potential environmental exposure associated with the improper disposal of waste masks and indicate strategies for sustainable mask disposal and management.

Advanced Tenderization of Brine Injected Pork Loin as Affected by Ionic Strength and High Pressure.

This study investigated the effects of brine injection and high hydrostatic pressure (HHP) on the quality characteristics of pork loin. Brine with ionic strength conditions (0.7% vs 1.5% NaCl, w/v) were injected into pork loins, and the meat was pressurized up to 500 MPa for 3 min. As a quality indicator, moisture content, color, cooking loss and texture profile analysis (TPA) of pork loins were estimated. Based on the results, brine with low ionic strength (0.7% NaCl) resulted in low injection efficiency and high cooking loss, although, it improved tenderness of pork loin at moderate pressure level (~200 MPa). While high ionic strength condition (1.5% NaCl injection) lowered the hardness of pork loins at relatively high HHP level (400-500 MPa), it also caused high cooking loss. To commercialize the brine injected pork loins, it was necessary to regulate brine compositions, which was not evaluated in this study. Nevertheless, the present study demonstrated that brine injection followed by moderate pressure (200 MPa) could improve the tenderness of pork loins without causing other major quality losses.

Idiopathic acute eosinophilic pneumonia in a 14-month-old girl.

Idiopathic acute eosinophilic pneumonia (IAEP), characterized by acute febrile respiratory failure associated with diffuse radiographic infiltrates and pulmonary eosinophilia, is rarely reported in children. Diagnosis is based on an association of characteristic features including acute respiratory failure with fever, bilateral infiltrates on the chest X-ray, severe hypoxemia and bronchoalveolar lavage fluid >25% eosinophils or a predominant eosinophilic infiltrate in lung biopsies in the absence of any identifiable etiology. We present a 14-month-old girl who was admitted to our pediatric intensive care unit because of acute respiratory distress. She had a fever, dry cough, and progressive dyspnea for 1 day. Chest X-ray showed multifocal consolidations, increased interstitial markings, parenchymal emphysema and pneumothorax. IAEP was confirmed by marked pulmonary infiltrates of eosinophils in the lung biopsy specimen. Most known causes of acute eosinophilic pneumonia, such as exposure to causative drugs, toxins, second-hand smoking and infections were excluded. Her symptoms were resolved quickly after corticosteroid therapy.

Assessment of bronchodilator responsiveness following methacholine-induced bronchoconstriction in children with asthma.

PURPOSE: The aim of this study was to investigate bronchodilator responsiveness (BDR) following methacholine-induced bronchoconstriction and to determine differences in BDR according to clinical parameters in children with asthma. METHODS: The methacholine challenge test was performed in 145 children with mild to moderate asthma, and the provocative concentration causing a 20% decline in FEV1 (PC20) was determined. Immediately after the challenge test, patients were asked to inhale short-acting ß2-agonists (SABAs) to achieve BDR, which was assessed as the change in FEV1% predicted×100/post-methacholine FEV1% predicted. For each subject, the asthma medication, blood eosinophil count, serum total IgE, serum eosinophil cationic protein level, and skin prick test result were assessed. RESULTS: The FEV1 (mean±SD) values of the 145 patients were 90.5±10.9% predicted, 64.2±11.5% predicted, and 86.2±11.2% predicted before and after methacholine inhalation, and following the administration of a SABA, respectively. The BDR did not differ significantly according to asthma medication, age, or gender. However, BDR in the atopy group (37.4±17.7%) was significantly higher than that in the non-atopy group (30.5±10.7%; P=0.037). Patients with blood eosinophilia (38.6±18.1%) displayed increased BDR compared with patients without eosinophilia (32.0±13.8%; P=0.037). CONCLUSIONS: In children with mild to moderate asthma, the responsiveness to short-acting bronchodilators after methacholine-induced bronchoconstriction was not related to asthma medication, but was higher in children with atopy and/or peripheral blood eosinophilia.