The Gas Diffusion Electrode Setup as Straightforward Testing Device for Proton Exchange Membrane Water Electrolyzer Catalysts.

Hydrogen production from renewable resources and its reconversion into electricity are two important pillars toward a more sustainable energy use. The efficiency and viability of these technologies heavily rely on active and stable electrocatalysts. Basic research to develop superior electrocatalysts is commonly performed in conventional electrochemical setups such as a rotating disk electrode (RDE) configuration or H-type electrochemical cells. These experiments are easy to set up; however, there is a large gap to real electrochemical conversion devices such as fuel cells or electrolyzers. To close this gap, gas diffusion electrode (GDE) setups were recently presented as a straightforward technique for testing fuel cell catalysts under more realistic conditions. Here, we demonstrate for the first time a GDE setup for measuring the oxygen evolution reaction (OER) of catalysts for proton exchange membrane water electrolyzers (PEMWEs). Using a commercially available benchmark IrO2 catalyst deposited on a carbon gas diffusion layer (GDL), it is shown that key parameters such as the OER mass activity, the activation energy, and even reasonable estimates of the exchange current density can be extracted in a realistic range of catalyst loadings for PEMWEs. It is furthermore shown that the carbon-based GDL is not only suitable for activity determination but also short-term stability testing. Alternatively, the GDL can be replaced by Ti-based porous transport layers (PTLs) typically used in commercial PEMWEs. Here a simple preparation is shown involving the hot-pressing of a Nafion membrane onto a drop-cast glycerol-based ink on a Ti-PTL.

Effect of breastfeeding versus infant formula on iron status of infants with beta thalassemia major.

BACKGROUND: Thalassemia major or Cooley's anemia is the most severe form of beta thalassemia in which the complete lack of beta protein in the hemoglobin causes a life-threatening anemia requiring regular blood transfusions and extensive ongoing medical care. These extensive, lifelong blood transfusions lead to iron-overload that must be treated with chelation therapy to prevent early death from organ failure. We compared serum iron and ferritin levels amongst infants aged up to one year with beta thalassemia major according to their feeding types, including exclusively breastfed, exclusively formula fed and combined (both breast and formula) fed types. METHODS: Sixty out of 176 screened infants with transfusion dependant beta thalassemia major were recruited from the outpatient clinic of thalassemia at Zagazig University Hospital in Egypt, between 2007 and 2014. Patients were classified into three groups (20 patients per group) according to type of feeding. Group 1: exclusive breastfeeding, around 6-8 feeds per day; group 2: exclusive infant formula feeding, 120-150 ml of formula per kilogram of body weight per day divided into 6-8 feeds and group 3: combined breastfeeding and formula per day. RESULTS: Serum iron and ferritin levels were lower in group 1 compared to groups 2 and 3. The mean serum iron for group 1 was 73, 87 and 96 ug/dl at 6, 9 and 12 months respectively, while that for group 2 was 85, 99 and 112 ug/dl at 6, 9 and 12 months respectively and for group 3 was 78, 92 and 99 ug/dl at 6, 9 and 12 months respectively. The mean serum ferritin for group 1 was 283, 327 and 497 ng/ml at 6, 9 and 12 months respectively, while that for group 2 was 310, 389 and 591 ng/ml at 6, 9 and 12 months respectively and for group 3 was 291, 345 and 515 ng/ml at 6, 9 and 12 months respectively. The differences were not statistically significant. CONCLUSIONS: Breastfed infants with beta thalassemia major may accumulate less iron than infants fed iron fortified formula anticipating later onset of iron overload in the breastfed infants. Larger studies are needed to support these findings.

Aberrant p16INK4A methylation: Relation to viral related chronic liver disease and hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is currently the fifth most common solid tumor worldwide and the third leading cause of cancer related deaths. Several studies have shown that the tumor suppressor gene p16INK4A is frequently downregulated by aberrant methylation of the 5'-cytosine-phosphoguanine island within the promoter region. AIM: To find out the frequency of methylated p16INK4A in the peripheral blood of HCC and cirrhotic patients and to evaluate its role in hepatocarcinogenesis. PATIENTS AND METHODS: This study was performed on 58 subjects: 30 HCC patients, 20 cirrhotic patients, and eight healthy volunteers. Methylation of p16INK4A was examined using methylation specific polymerase chain reaction (PCR) (MSP). Comparison of quantitative variables between the study groups was done using Mann-Whitney U test for independent samples when not normally distributed. For comparing categorical data, Chi-square (χ(2)) test was performed. Exact test was used instead when the expected frequency was less than 5. RESULTS: Methylation of p16INK4A was found in 6.7% of HCC patients, 5% of liver cirrhosis (LC) patients, and none of the healthy volunteers; 66.67% of the p16INK4A-methylated cases (2/3) were positive for anti-hepatitis C virus (HCV) antibodies (one of them had HCC). All HCC cases with aberrant p16INK4A methylation show very high serum alpha fetoprotein (AFP) level (9,080; 30,000 µg/mL). There were no significant associations between the status of p16INK4A methylation and tumor size. CONCLUSION: Hypermethylation of p16INK4A was found to be infrequent among Egyptian patients with HCC.