Carbon Black Nanoparticles Exposure Induces Intestinal Flora Dysbiosis and Consequent Activation of Gut-liver Axis Leading to Liver Lipid Accumulation in Zebrafish

BackgroundCarbon black nanoparticles (CBNPs) are a major carbonaceous nanomaterial, which have been widely left in the environment. The integrity of the gut-liver axis function is critical to the survival of animals. Therefore, we studied the effects of three concentrations of CBNPs (50, 100, 200 mg/L) on zebrafish intestines, liver and intestinal flora. ResultsThe results showed that CBNPs exposure could reduce the diversity of intestinal flora, change the structure of core microbial populations, enhance the permeability of the intestinal mucosal barrier, and cause changes in genes related to tight junctions in intestinal tissues. The H&E staining and Oil red O staining showed that CBNPs exposure would lead to vacuolar degeneration and lipid accumulation in zebrafish liver. Further detection of glycolipid metabolism related genes showed that CBNPs exposure induced the up-regulation of glycolysis related genes PFKFB3, LDHA, and LEPr, reduces the expression of glycogen synthase kinase GSK-3b, and increases lipid transport and production related genes PPAR-α, PPAR-γ, LIPC, apoa4, Fabp2 and Fabp11 expression. ConclusionsIn brief, our data demonstrated that CBNPs exposure induced intestinal microflora disturbance in zebrafish can lead to liver lipid accumulation.

Carbon-Silica Composites with Cellulose Acetate, Polyisocyanate and Copper Chloride

Cellulose acetate and polyisocyanate copolymer synthesized by simultaneous mixing of cellulose acetate and polyisocyanate with acetone solution of Copper chloride and fumed silicon dioxide was carbonized in a silicon dioxide template. The composite structure and composition was studied with SEM, EDS and XRD. It was shown that the porous carbonaceous nanomaterial was synthesized where formed carbon was represented by coating on silicon dioxide and consisted of graphite, graphene and amorphous nonstructured carbon. Crystals of metallic copper with the size up to few µm were formed from Copper chloride after reduction of Cu2+ with products of organic compounds pyrolisis.

Synthesis of Carbon-Silica Nanomaterials by Carbonization of Cellulose Acetate and Polyisocyanate Copolymer

Cellulose acetate and polyisocyanate copolymer synthesized by mechanical mixing of cellulose acetate, polyisocyanate and fumed silicon dioxide in the presence of nickel chloride was carbonized in silicon dioxide template. Copolymer and silicon dioxide template were formed simultaneously. Composite structure and composition was studied with SEM and EDS. SEM showed that porous carbonaceous nanomaterial was synthesized. Formed carbon is represented by coating on silicon dioxide, layered ribbon-like and fibrous structures in template pores with size from several nm (thickness) to several microns (length). Metallic nickel crystals up to 200 nm in size were fabricated in composite pores from Nickel chloride by reduction of Ni2 with products of pyrolysis of organic compounds.

Feasibility of Carbonaceous Nanomaterial-Assisted Photocatalysts Calcined at Different Temperatures for Indoor Air Applications

This study examined the characteristics and photocatalytic activity of multiwall carbon nanotube-assisted TiO2(MWNT-TiO2) nanocomposites calcined at different temperatures to assess their potential indoor air applications. It was confirmed that the composites calcined at low temperatures (300 and 400°C) contained TiO2nanoparticles bound intimately to the MWNT networks. Meanwhile, almost no MWNTs were observed when the calcination temperature was increased to 500 and 600°C. The MWNT-TiO2composites calcined at low temperatures showed higher photocatalytic decomposition efficiencies for aromatic hydrocarbons at indoor concentrations than those calcined at high temperatures. The mean efficiencies for benzene, toluene, ethyl benzene, and o-xylene (BTEX) by the composite calcined at 300°C were 32, 70, 79, and 79%, respectively, whereas they were 33, 71, 78, and 78% for the composite calcined at 400°C, respectively. In contrast, the efficiencies decreased to close to zero when the calcination temperature was increased to 600°C. Moreover, the MWNT-TiO2exhibited superior photocatalytic performance for the decomposition efficiencies compared to TiO2under conventional UV-lamp irradiations. Consequently, these carbonaceous nanomaterial-assisted photocatalysts can be applied effectively to indoor air applications depending upon the calcination temperature.