Rhodium metallene-supported platinum nanocrystals for ethylene glycol oxidation reaction.

Low-temperature fuel cells have great application potential in electric vehicles and portable electronic devices, which need advanced electrocatalysts. Controlling the composition and morphology of electrocatalysts can effectively improve their catalytic performance. In this work, a Rh metallene (Rhlene)-supported Pt nanoparticle (Pt/Rhlene) electrocatalyst is successfully synthesized by a simple chemical reduction method, in which ultra-small Pt nanoparticles are uniformly attached to the Rhlene surface due to the high surface area of Rhlene. Pt/Rhlene reveals a 3.60-fold Pt-mass activity enhancement for the ethylene glycol oxidation reaction in alkaline solution compared with commercial Pt black, and maintains high stability and excellent poisoning-tolerance during electrocatalysis, owing to the specific physical/chemical properties of Rhlene. The superior electrocatalytic performance of Pt/Rhlene may open an avenue to synthesize other metallene-supported noble metal nanoparticle hybrids for various electrocatalytic applications.

Fumonisin B1 Affects the Biophysical Properties, Migration and Cytoskeletal Structure of Human Umbilical Vein Endothelial Cells.

Fumonisin B1 (FB1) is an important mycotoxin in nature and is a serious threat to human and animal health, but its specific target and molecular mechanism of the toxicity and potential carcinogenicity remain unclear. In this study, we first detected the effects of FB1 on the cell viability, biophysical properties, migration ability, and reactive oxygen species (ROS) of human umbilical vein endothelial cells (HUVECs). Subsequently, changes in the cytoskeletal structure and its binding proteins were analyzed by immunofluorescence and real-time PCR, respectively. The results showed that FB1 could inhibit the viability of HUVECs in a dose-dependent manner. After treatment of HUVECs with FB1, the hypotonic resistance, cell surface charges, cell membrane fluidity, and migration ability were weakened, whereas the ROS levels were significantly increased. Moreover, the cytoskeletal structure of the HUVECs was significantly changed, and the mRNA expression of some important actin-binding proteins was altered. Therefore, this study revealed that FB1 can affect the migration and cytoskeletal structure of HUVECs, which provides a new perspective for further understanding the molecular mechanisms of FB1 toxicity.

[Semen quality of normal fertile men].

OBJECTIVE: To study the semen quality of confirmed fertile men with the time to pregnancy (TTP) of 12 months or less, and analyze the correlation of semen parameters with TTP. METHODS: We recruited 1 152 men aged 18 -50 years and with TTP of 12 months. We used questionnaire investigation, physical examination and semen analysis, calculated the normal reference ranges of semen parameters, and analyzed the effects of TTP and other biological characteristics on semen quality. RESULTS: Seminal examinations showed that the semen volume was 1.5 ml, sperm concentration 17 million per ml, total sperm number 39 million per ejaculate, total sperm motility 41%, progressive sperm motility 33%, normal sperm morphology 5.0%, sperm vitality 53%, and total number of progressively motile sperm 17 million per ejaculate in the 1 152 subjects. In comparison, the total number of progressively motile sperm was significantly smaller in those aged > or = 35 years (P < 0.01), morphologically normal sperm were markedly less in those with BMI > 25.0 (P < 0.01), and sperm concentration, total number of sperm, morphologically normal sperm rate and total number of progressively motile sperm were remarkably lower in those with BMI < 18. 5 (P < 0.05). Cigarette smoking significantly reduced the sperm volume (P < 0.01), and drinking (> 10 g per week) decreased the sperm volume and the total numbers of sperm, morphologically normal sperm and progressively motile perm (P < 0.05). TTP was negatively correlated with sperm concentration, total number of sperm and total number of progressively motile sperm (P < 0.01). The subjects with sexual abstinence of 5 -7 days showed markedly higher sperm concentration, total number of sperm and total number of progressively motile sperm than others (P < 0.01). CONCLUSION: In normal fertile men, the fifth centile of semen parameters is close to the WHO normal reference range, TTP is negatively correlated with semen quality, and age, BMI and lifestyle may affect some of the semen parameters.