Structure and Adsorption Performance of Cationic Entermorpha prolifera Polysaccharide-Based Hydrogel for Typical Pollutants: Methylene Blue, Cefuroxime, and Cr (VI)

Hydrogels with polysaccharides as high polymer substrates have surprising advantages in wastewater treatment with complex components. Therefore, in this study, polysaccharides named EPS were extracted from Enteromorpha prolifera, a coastal pollutant with a wide range of sources, and cationic modification was performed to obtain CAEPS, the hydrogel with a double network structure was prepared based on EPS and CAEPS. Meanwhile, the structural characteristic of EPS and CAEPS-based hydrogel were identified by HPLC, AFM, FT-IR, TGA, SEM-EDS, Pore size distribution, and WCA, which showed that the porosity, apparent (skeletal) density, and hydrophilicity of CAEPS-hydrogels. We used nonlinear isotherms to uncover the adsorption mechanism of hydrogel applied to the water environment containing three typical pollutants (Methylene blue, Cefuroxime, and Cr (VI)). The results showed that the adsorption isotherm of the two hydrogels fit the Langmuir isotherm model, which indicated the monolayer adsorption of the pollution factor onto EPS- and CAEPS-hydrogels. The maximum adsorption capacities of CAEPS-hydrogels were higher than EPS-hydrogels, which indicated the microstructure and adsorption performance of the CAEPS-hydrogel are strengthened.

A polysaccharide-based bioflocculant BP50-2 from banana peel waste: Purification, structure and flocculation performance.

In this study, the purification and characterization of a polysaccharide-based bioflocculant BP50-2 of banana peel waste were investigated. BP50-2 was purified and identified through HPLC, XPS, TG, SEM, AFM, etc. The results showed that BP50-2 was a heteropolysaccharide composed of Mannose, Rhamnose, Glucuronic acid, Galacturonic acid, Glucose, Galactose, and Fucose at a molar ratio of 8.97:5.36:1.92:1.00:32.52:8.30:2.64, respectively. The MW of BP50-2 was 1.47 × 10 3 KDa. BP50-2 had high pH stability that maintained flocculation activity on kaolin suspension for a pH range from 3 to 11, and high-temperature stability ranged from room temperature to 90 °C. BP50-2 was non-sensitive to cation and affected by HCl, EDTA, little affected by urea, which showed that the BP50-2 was non-cation dependent and its main binding mode with kaolin was ionic bond and contained a small amount of hydrogen bond. And flocculation mechanisms were discussed, which indicated that adsorption bridging was the main mechanism of the flocculation process of BP50-2-Kaolin or BP50-2-Mg2+-Kaolin. Moreover, BP50-2 had decolorization activity on RhB and removal activity of heavy metal ion, of which removal rate of Pb2+ was the highest. In brief, BP50-2 showed good performance on the removal of pigment, adsorption of heavy metals, and flocculation of particles.

Degradation of Rhodococcus erythropolis SY095 modified with functional magnetic Fe3O4 nanoparticles.

Alkali-surfactant-polymer flooding technology is widely employed to extract crude oil to enhance its production. The bacterial strain Rhodococcus erythropolis SY095 has shown high degradation activity of alkane of crude oil. In the past, many treatment strategies have been implemented to reduce oil concentration in wastewater. Previous studies mainly focused on the extracellular products of Erythrococcus rather than its degradation properties. In the current study, we designed an immobilization method to modify the surface of R. erythropolis SY095 with functional Fe3O4 nanoparticles (NPs) for biodegradation of crude oil and separation of the immobilized bacteria after degradation. We characterize the synthesized NPs through various methods, including scanning electron microscope energy-dispersive spectrometer, Fourier transform infrared spectroscopy, X-ray diffraction (XRD) and a vibrating sample magnetometer. We found that the size of the synthesized NPs was approximately 100 nm. Our results showed that R. erythropolis SY095 was successfully coated with functional magnetic NPs (MNPs) that could be easily separated from the solution via the application of an external magnetic field. The coated cells had a high tolerance for heavy metals. Our findings demonstrated that the immobilization of MNPs to bacterial surfaces is a promising approach for the degradation of crude oil.

Nicotine favors osteoclastogenesis in human periodontal ligament cells co-cultured with CD4(+) T cells by upregulating IL-1ß.

Periodontitis, which is the main cause of tooth loss, is one of the most common chronic oral diseases in adults. Tooth loss is mainly a result of alveolar bone resorption, which reflects an increased osteoclast formation and activation. Osteoclast formation in periodontal tissue is a multistep process driven by osteoclastogenesis supporting cells such as human periodontal ligament (PDL) cells and CD4(+) T cells. Inflammatory cytokines, such as interleukin-1ß (IL-1ß), can induce osteoclastogenesis by affecting the expression of receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) in human PDL cells. Nicotine, the major component in tobacco smoking and a specific agonist of the α7 nicotinic acetylcholine receptor (α7 nAChR), has been proven to regulate the expression of inflammatory cytokines in smoking-associated periodontitis. In this study, we investigated the mechanism(s) through which nicotine affects osteoclastogenesis in human PDL cells co-cultured/non-co-cultured with CD4(+) T cells. Human PDL cells were stimulated with nicotine (10-5 M) and/or α-bungarotoxin (α-BTX, specific antagonist of α7 nAChR, 10-8 M) before being co-cultured with CD4(+) T cells. Compared with mono-culture systems, stimulation with nicotine caused an increased secretion of IL-1ß in serum of human PDL cell-CD4(+) T cell co-culture, and the expression of RANKL in human PDL cells was further upregulated co-cultured with CD4(+) T cells, while no differences were observed in the expression of OPG between the co-culture and mono-culture systems. Our data suggested that nicotine upregulated IL-1ß secretion, further upregulated RANKL expression in smoking-associated periodontitis, which may aid in the better understanding of the relationship between nicotine and alveolar bone resorption.

Treatment for a complicated crown-root fracture with intentional replantation: a case report with a 3.5-year follow up.

Crown-root fractures are always challenging for pediatric dentists because of their complicated treatments and uncertain prognosis. The purpose of this case report was to describe a severe crown-root fracture successfully treated by multidisciplinary approaches including intentional replantation. After a 3.5-year follow up, the patient felt comfortable and satisfied with her tooth, and the prosthesis was functionally and esthetically acceptable. It is recommended that multidisciplinary treatment with intentional replantation is effective and necessary for similar cases to be conservatively managed.