Water pollution caused by antibiotics is a growing problem. Semiconductor photocatalysis is an environmentally friendly technology that can effectively degrade organic pollutants in water. Therefore, the development of efficient photocatalysts is of great significance to solve the environmental pollution problem. In this paper, mixed-phase TiO2 and 1T/2H-MoS2 composite (1T/2H-MoS2/TiO2) were synthesized by the in situ growth method. The prepared compounds were characterized and applied to the visible-light degradation of tetracycline hydrochloride. The photocatalytic effect of 1T/2H-MoS2/TiO2 on tetracycline hydrochloride is significantly enhanced under visible light and has good stability. It has potential applications in the treatment of organic pollutants in water.
Esophageal squamous cell carcinoma accounts for a large proportion of cancer-associated mortalities in both men and women. Melittin is the major active component of bee venom, which has been reported to possess anti-inflammatory, antibacterial and anti-cancer properties. The aim of the present study was to construct a tumor targeted recombinant plasmid [pc-telomerase reverse transcriptase (TERT)-melittin] containing a human TERT promoter followed by a melittin coding sequence and to explore the effects of this plasmid in esophageal cell carcinoma and investigate preliminarily the underlying mechanisms of this effect. TE1 cells were transfected with pcTERT-melittin and the resulting apoptosis was subsequently examined. The viability of TE1 cells transfected with pcTERT-melittin was measured using a Cell Counting Kit-8 assay, which indicated inhibited proliferation. The disruption of mitochondrial membranes and the concomitant production of reactive oxygen species demonstrated an inducible apoptotic effect of melittin in TE1 cells. Apoptotic cells were also counted using an Annexin V-FITC and PI double-staining assay. The upregulation of cleaved caspase-9, cleaved caspase-3, Bax and poly(ADP-ribose) polymerase 1 in pcTERT-melittin transfected TE1 cells, suggested that pcTERT-melittin-induced apoptosis was associated with the mitochondrial pathway. TE1 cells were also arrested in the G0/G1 phase when transfected with pcTERT-melittin, followed by the decline of CDK4, CDK6 and cyclin D1 expression levels. As cell invasion and metastasis are common in patients with esophageal cancer, a cell migration assay was conducted and it was found that pcTERT-melittin transfection reduced the migratory and invasive abilities of TE1 cells. The findings of the present study demonstrated that pcTERT-melittin may induce apoptosis of esophageal carcinoma cells and inhibit tumor metastasis.
1T-MoS2 is in situ grown on TiO2 nanotubes (TNTs) using a hydrothermal method, forming a 1T-MoS2@TNTs composite, which is confirmed by its physical characterization. The prepared composites show enhanced photocatalytic performance for the degradation of tetracycline hydrochloride under visible light, and the improved photocatalytic activity is closely related to the loaded amount of 1T-MoS2. Therein, 0.5 wt % 1T-MoS2@TNTs can degrade 57% in 1 h, which is the highest photocatalytic efficiency observed in experiments so far. It is speculated that the introduction of 1T-MoS2 may optimize light absorption and charge separation/transport. The active species are identified and the reaction mechanism is proposed here.
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