RESUMO
Support corrosion is a traditional intractable problem for oxygen electrodes of fuel cells, so developing anti-corrosion supports is highly desirable. Herein, we fabricate a three-dimensional (3D) interconnected-graphene enveloped titanium dioxide flower (TiO2@RGO) as a robust support for the oxygen reduction reaction (ORR). Benefiting from the unique 3D architecture, the TiO2@RGO composite possesses both a large surface area of 174 m2 g-1 and a superior electrical conductivity of 0.19 S cm-1, enabling an electron highway for efficient simultaneous mass transfer of reactants. After loading Pt nanoparticles, the Pt-TiO2@RGO catalyst exhibits a similar catalytic activity to the commercial Pt/C catalyst, while superior stability under the accelerated degradation protocols for both catalysts (0.6-1.0VRHE) and supports (1.0-1.5VRHE), due to the strong metal-support interaction (SMSI) of Pt nanoparticles and the TiO2@RGO composite support. The PEMFC with the Pt-TiO2@RGO cathode delivers a peak power density of 901 mW cm-2, which is comparable to that with a Pt/C cathode. This work proposes a new strategy for designing robust catalyst supports for PEMFCs.
RESUMO
Yueju, a famous classic Chinese prescription, has been extensively used in treating depression syndromes for hundreds of years. Recent studies have reported that Yueju showed good effects in treating metabolic diseases, such as obesity and hyperlipidemia. Nonalcoholic steatohepatitis (NASH), which leads to cirrhosis and severe cardiovascular diseases, is closely linked to obesity and abnormal lipid metabolism. In this study, Yueju could decrease the levels of alanine aminotransferase, aspartate transaminase, triglyceride, cholesterol, and low-density lipoprotein-C but increase the high-density lipoprotein-C in the serum of the NASH rat model induced by high-fat and high-cholesterol diet. Yueju could alleviate hepatosteatosis by increasing the phosphorylation of acetyl-CoA carboxylase and inhibiting the expression of fatty acid synthase and stearoyl-CoA desaturase 1. Yueju downregulated the expression of α-smooth muscle actin and collagen type 1A1, ameliorating the liver fibrilization. Yueju could also protect the hepatocytes from apoptosis by upregulating antiapoptosis protein Bcl-2 and X-linked inhibitor of apoptosis protein and downregulating apoptotic proteins Bax and cleaved poly ADP-ribose polymerase. Thus, Yueju could improve liver function, regulate lipid metabolism, alleviate hepatosteatosis and fibrosis, and protect hepatocytes from apoptosis against NASH. Yueju may be used as an alternative effective medicine for NASH treatment.
RESUMO
PURPOSE: Omentin-1 has been identified as interesting novel adipokines that may modulate insulin action. Its exact biological function is unclear. The aim of this study is to assay the levels of serum omentin-1 in normal subjects and type 2 diabetes mellitus (T2DM) with normal weight, overweight and obesity and to analyze the relationship between serum omentin-1 levels with body mass index (BMI), waist to hip ratio (WHR), glycosylated hemoglobin (HbA1c), plasma glucose, insulin resistance index (HOMA-IR) and serum lipid levels. METHODS: There are eighty newly diagnosed type 2 diabetes patients, thirty-five type 2 diabetes patients with normal weight, twenty-nine type 2 diabetes patients with overweight, sixteen type 2 diabetes patients with obesity, and forty healthy control subjects were enrolled in this study. The levels of plasma glucose at fasting and 2-hour postprandial blood glucose and fasting serum levels of insulin, omentin-1and HbA1c were measured. HOMA-IR was calculated. RESULTS: Serum omentin-1 levels were found to be significantly decreased in type 2 diabetes patients with normal weight (821.16 ± 312.50 ng/L), in type 2 diabetes patients with overweight (748.00±322.51 ng/L), and in type 2 diabetes patients with obesity (530.44±357.35 ng/L) compared with healthy control subjects (994.71±435.90 ng/L) at P<0.05. The level of serum omentin-1 was negatively correlated to BMI, HOMA-IR, WHR, fasting insulin (FINS), fasting plasma glucose (FPG), 2-hour postprandial blood glucose (2HPG), triglycerides (TG), and positively correlated to high-density lipoprotein (HDL). BMI was independent related factor that influenced the levels of serum omentin-1. CONCLUSION: Decreased omentin-1 levels may contribute to the development of insulin resistance, T2DM and particularly to obesity in Chinese adults, however, its role in these diseases needs to be fully elucidated.