Gamma-Ray Irradiation Induced Ultrahigh Room-Temperature Ferromagnetism in MoS2 Sputtered Few-Layered Thin Films.

Defect engineering is of great interest to the two-dimensional (2D) materials community. If nonmagnetic transition-metal dichalcogenides can possess room-temperature ferromagnetism (RTFM) induced by defects, then they will be ideal for application as spintronic materials and also for studying the relation between electronic and magnetic properties of quantum-confined structures. Thus, in this work, we aimed to study gamma-ray irradiation effects on MoS2, which is diamagnetic in nature. We found that gamma-ray exposure up to 9 kGy on few-layered (3.5 nm) MoS2 films induces an ultrahigh saturation magnetization of around 610 emu/cm3 at RT, whereas no significant changes were observed in the structure and magnetism of bulk MoS2 (40 nm) films even after gamma-ray irradiation. The RTFM in a few-layered gamma-ray irradiated sample is most likely due to the bound magnetic polaron created by the spin interaction of Mo 4d ions with trapped electrons present at sulfur vacancies. In addition, density functional theory (DFT) calculations suggest that the defect containing one Mo and two S vacancies is the dominant defect inducing the RTFM in MoS2. These DFT results are consistent with Raman, X-ray photoelectron spectroscopy, and ESR spectroscopy results, and they confirm the breakage of Mo and S bonds and the existence of vacancies after gamma-ray irradiation. Overall, this study suggests that the occurrence of magnetism in gamma-ray irradiated MoS2 few-layered films could be attributed to the synergistic effects of magnetic moments arising from the existence of both Mo and S vacancies as well as lattice distortion of the MoS2 structure.

Observation of the clinical efficacy of isotope phosphorus-32 dressing combined with diprospan and mucopolysaccharide polysulphate cream in the treatment of keloids.

OBJECTIVE: The present study aims to investigate the effectiveness, recurrence, and adverse reaction rates of isotope phosphorus-32 dressings combined with diprospan and mucopolysaccharide polysulphate cream in the treatment of keloids. METHODS: A total of 80 patients with keloids admitted to the Dermatology Clinic of the Fourth Affiliated Hospital of Harbin Medical University between June 2019 and June 2021 were included in the present study and randomly divided into three groups: Control Group 1 (n = 27), Control Group 2 (n = 25), and the treatment group (n = 28). Patients in Control Group 1 were treated with diprospan combined with mucopolysaccharide polysulphate cream, patients in Control Group 2 were treated with an isotopic phosphorus-32 dressing combined with mucopolysaccharide polysulphate cream, and patients in the treatment group were treated with an isotopic phosphorus-32 dressing combined with diprospan and mucopolysaccharide polysulphate cream. The effectiveness, recurrence, and adverse reaction rates were observed in all three groups. RESULTS: The treatment group had the most significant decrease in the itching scores. The respective effectiveness, recurrence, and adverse reaction rates were 81.4%, 43.6%, and 74.1% in Control Group 1; 56%, 38.7%, and 64% in Control Group 2; and 96.7%, 11.2%, and 41% in the treatment group. The differences were statistically significant (p < 0.05). CONCLUSION: An isotope phosphorus-32 dressing combined with diprospan and mucopolysaccharide polysulphate cream keloid treatment delivers a fast onset, good effectiveness, and low recurrence and adverse effect rates.

Cosolvent-Driven Interfacial Polymerization for Superior Separation Performance of Polyurea-Based Pervaporation Membrane.

A thin-film composite (TFC) polyurea membrane was fabricated for the dehydration of an aqueous tetrahydrofuran (THF) solution through interfacial polymerization, wherein polyethyleneimine (a water-soluble amine monomer) and m-xylene diisocyanate (an oil-soluble diisocyanate monomer) were reacted on the surface of a modified polyacrylonitrile (mPAN) substrate. Cosolvents were used to tailor the membrane properties and increase the membrane permeation flux. Four types of alcohols that differed in the number of carbon (methanol, ethanol, isopropanol, and tert-butanol) were added as cosolvents, serving as swelling agents, to the aqueous-phase monomer solution, and their effect on the membrane properties and pervaporation separation was discussed. Attenuated total reflection Fourier transform infrared spectroscopy confirmed the formation of a polyurea layer on mPAN. Field emission scanning electron microscopy and surface water contact angle analysis indicated no change in the membrane morphology and hydrophilicity, respectively, despite the addition of cosolvents for interfacial polymerization. The TFC membrane produced when ethanol was the cosolvent exhibited the highest separation performance (permeation flux = 1006 ± 103 g·m-2·h-1; water concentration in permeate = 98.8 ± 0.3 wt.%) for an aqueous feed solution containing 90 wt.% THF at 25 °C. During the membrane formation, ethanol caused the polyurea layer to loosen and to acquire a certain degree of cross-linking. The optimal fabrication conditions were as follows: 10 wt.% ethanol as cosolvent; membrane curing temperature = 50 °C; membrane curing time = 30 min.