Preparation and Tribological Properties of a Multilayer Graphene-Reinforced TiO2 Composite Nanolubricant Additive.

The unique structure and physical properties of graphene and anatase TiO2 make them suitable for use as additives for engine lubricants. This study describes the use of dielectric barrier discharge plasma-assisted ball milling to synthesize a multilayer graphene-reinforced TiO2 composite nanolubricant additive (MGTC). A variety of physical and chemical tests were performed to characterize the resulting experimental materials, including X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Raman, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Four-ball friction and wear testing machines were used to study the tribological properties and extreme pressure anti-wear properties of a base oil containing 0.1, 0.5, 1.0, and 1.5 wt % of the modified TiO2. Raman spectroscopy, XPS, SEM, and energy-dispersive spectrometry (EDS) analyses were used to examine and analyze the microstructure of the friction pairs. As a result of the plasma-assisted ball milling process, expanded graphite was successfully separated into multilayer graphene nanosheets, and spherical TiO2 was successfully bonded to the nanosheets of the multilayer graphene. The 1.0 wt % composite oil was found to provide good friction reduction and wear resistance. It had a film thickness of 27.5 nm, which was 167% thicker than base oil. Due to its excellent dispersion stability, the MGTC nanocomposite exhibited excellent lubrication performance, which was attributed to the formation of carbon protective films, titanium dioxide deposition films, transfer films, and the occurrence of nano ball effects on the surface of friction pairs.

Genetic Toxicology and Safety Pharmacological Evaluation of Forsythin.

INTRODUCTION: Forsythin is the main ingredient of Forsythia suspensa and is widely used in treatment of fever, viral cold, gonorrhea, and ulcers clinically. This study aimed to evaluate the potential genetic toxicity of forsythin and its safety for human use. METHODS: Based on the Good Laboratory Practice regulations and test guidelines, the genetic toxicity of forsythin was assessed by the Ames test, chromosome aberration (CA) test, and bone marrow micronucleus (MN) test in vivo. In the Ames test, five strains of Salmonella typhimurium were exposed to different concentrations of forsythin in the presence or absence of the S9 mixture, and then, the number of His + revertant colonies was counted. In the CA test, Chinese hamster lung (CHL) fibroblast cells were treated with different concentrations of forsythin, mitomycin C, or cyclophosphamide in the presence or absence of the S9 mixture, and the chromosomal aberrations were determined. In the MN test, bone marrow was isolated from the mice with different treatments, and the ratios of polychromatic erythrocytes (PCE) and erythrocytes (PCE/(PCE + NCE)) were measured. Finally, beagle dogs were divided into four groups (negative control, low dose, medium dose, and high dose groups), and then, a telemetry system was used to evaluate the safe use of forsythin. RESULTS: Ames test results showed that the number of colonies in all test strains with different treatments showed no significantly dose-dependent increase in the presence or absence of the S9 mixture (p > 0.05). In the CA test, the number of cells with aberrations in the CHL fibroblast cells treated with low, medium, and high doses of forsythin for 24/48 h in the absence of the S9 mixture was, respectively, 5.0/2.5, 4.5/1.5, and 5.0/5.0, and in the presence of the S9 mixture, the number was, respectively, 5.0, 5.0, and 4.5. These results showed that there was no significant difference compared to the negative control group either in the presence (2.0) or in the absence (4.0/2.5 for 24/48 h) of the S9 mixture (p > 0.05). The MN test showed that the values of PCE/(PCE + NCE) in the negative, positive controls, and forsythin treatment groups were all more than 20%, which indicated that forsythin had no cytotoxicity. Additionally, no significant toxicological effects of forsythin on blood pressure, respiration, temperature, electrocardiogram, and other physiological indicators in the conscious beagle dogs of different groups were observed by the telemetry method. CONCLUSION: Our findings showed that forsythin has low probability of genetic toxicity and no significant toxicological effects, which implied that forsythin is suitable for further development and potential application.

Identification of genes underlying the enhancement of immunity by a formula of lentinan, pachymaran and tremelia polysaccharides in immunosuppressive mice.

The efficacy of polysaccharides is widespread, especially in immune regulation. However, the genetic basis of the changes in polysaccharides regulating immunity is unclear. To obtain genome-wide insights into transcriptome changes and regulatory networks, we designed a polysaccharide formula, comprising lentinan, pachymaran and tremelia, to increase the availability of their optimized active sites. In this case, we focused on a model of immunosuppression to investigate genes by digital gene expression (DGE) tag profiling in T and B cells. These genes were further validated by qRT-PCR and Western blot experiments. Consequently, polysaccharide formula treatment helped to recover the expression of immune-related genes, including CADM1, CCR2, IGLL1, LIGP1, and FCGR3, FCGR2 in B cells, as well as S100A8, S100A9, ChIL3, MMP8 and IFITM3 in T cells. These results suggest that treatment with polysaccharides improves the immunity of immunosuppressive mice by regulating genes associated with T and B cell functions.

Effects of ceftriaxone induced intestinal dysbacteriosis on lymphocytes in different tissues in mice.

The close relationship between intestinal microflora and immune system has been confirmed, stimulus from intestinal flora plays an important role in the development of the immune system and its dynamic balance. Current research is still inadequate to determine how local bacteria in gut influence the whole body. In this study, influence of ceftriaxone sodium induced intestinal dysbacteriosis on local and overall immune function was investigated. We found that the beneficial bacteria decreased significantly compared with control after oral administration of ceftriaxone; Moreover, the proportion of T cells are higher and B cells are lower in the dysbacteriosis mice, activation and proliferation of T and B cells was decreased significantly in gut-associated lymphoid tissues (GALTs), such as Peyer's patches (PPs) and mesenteric lymph nodes(MLNs)with ceftriaxone treatment; The secreted sIgA in intestinal was reduced in dysbacteriosis mice than that of control as well. The similar results above are also shown on the spleen. In addition, the delayed type hypersensitivity (DTH) reaction decreased in dysbacteriosis mice. The present data suggested that intestinal microflora had impact on immune system by influencing the proportion and function of lymphocytes in PPS-MLN-spleen.