A novel iron-porphyrin-derived oxygen sensor working near 0 V (vs. Ag/AgCl) in neutral solution

A metalloporphyrin film modified platinum (Pt) electrode was prepared by electrochemical polymerizing of iron(III)-tetra(3-methoxy-4-hydroxyphenyl) porphyrin on a platinum electrode. Cyclic voltammetry of the electrode in PBS pH 7.0 shows the dioxygen reduction peak close to 0 V (vs. Ag/AgCl). Rotating disk electrode experiments indicate a four-electron transfer mechanism of dioxygen reduction. The chemically modified electrode is recommended as a potential oxygen sensor working at a relatively low potential

Comparative study of hydrogel-immobilized L-glutamate oxidases for a novel thick-film biosensor and its application in food samples

Novel, thick-film biosensors have been developed for the determination of L-glutamate in foodstuffs. The sensors were prepared by immobilization of L-glutamate oxidase by using polycarbamylsulfonate-hydrogel on a thick-film sensor. L-Glutamate oxidases obtained from Streptomyces sp. with different degree of purification were compared with their characteristic response to L-glutamate at different conditions and for their specificity, inhibition, and storage properties. These sensors were applied to determine monosodium glutamate in soy sauce samples and show good correlation with colorimetric method

Apple puree as a natural fructose source provides an effective alternative carbohydrate source for fuelling half-marathon running performance

Carbohydrate supplementation during endurance exercise is known to improve performance, but the effects of food-based approaches in running exercise are understudied. Therefore, this study investigated the performance and gastrointestinal (GI) effects of a carbohydrate supplement containing a natural fructose source compared with a highly processed fructose source in a combined glucose-fructose supplement, during a half-marathon. Eleven trained runners (9 males, 2 females; age 32 ± 8 y, 89:53 ± 13:28 min half-marathon personal record) completed a familiarisation (8 miles) and two experimental trials (13.1 miles) on an outdoor running course, with blood and urine samples collected before and after the run. Subjective GI measures were made throughout the run. Carbohydrate was provided as a natural fructose source in the form of apple puree (AP) or highly processed crystalline fructose (GF) in a 2:1 glucose-to-fructose ratio (additional required glucose was provided through maltodextrin). Half-marathon performance was not different between carbohydrate sources (AP 89:52 ± 09:33 min, GF 88:44 ± 10:09 min; P = 0.684). There were no interaction effects for GI comfort (P = 0.305) or other GI symptoms (P ≥ 0.211). There were no differences between carbohydrate sources in ad libitum fluid intake (AP 409 ± 206 mL; GF 294 ± 149 mL; P = 0.094) or any other urinary (P ≥ 0.724), blood-based (P ≥ 0.215) or subjective (P ≥ 0.421) measures. Apple puree as a natural fructose source was equivalent to crystalline fructose in supporting half-marathon running performance without increasing GI symptoms.  Highlights: Research examining food-first and food-based approaches to carbohydrate supplementation and endurance running performance are limited. Therefore, this study aimed to compare carbohydrate supplements either containing a natural or highly processed fructose source as part of a glucose-fructose supplement on half-marathon running performance and gastrointestinal comfort in trained runners. Running performance (apple puree 89:52 ± 09:33 min vs. crystalline fructose 88:44 ± 10:09 min), gastrointestinal comfort and symptoms were not different between the two fructose sources. Apple puree can be effectively used as a carbohydrate source to fuel half-marathon running performance.</p

A Political Economy of Positions in Climate Change Negotiations: Economic, Structural, Domestic, and Strategic Explanations

After the disappointing outcome of the Copenhagen climate summit, it still remains to be explained why the participating states chose irreconcilable negotiation positions that reflected very diverse domestic interests in spite of a publicly displayed wish for cooperation. While environmental studies have intensely investigated national climate policies and their determinants over the last few decades, little attention has been paid to the bargaining positions the same governments assume in climate negotiations. We argue that their bargaining positions reflect structural, economic, and domestic factors, but less so strategic factors. A country’s vulnerability to climate change, its power and its democratic status are among the best predictors of its choice of negotiation position; its international interconnectedness, on the other hand, does not seem to have an influence. By comparing two negotiation issues – reducing emissions and financing climate mitigation – we can show that democracies choose rather different negotiation positions. When it comes to compensation mechanisms, democracies do not commit to substantial emission reduction targets due to pressure from industry at home. They are, however, more prepared than other states to pay for projects that help to reduce emissions. By understanding the choice of negotiation positions we can thus explain why the more or less cooperative bargaining positions adopted by states led to a breakdown of the Copenhagen negotiations. We investigated this question using a novel dataset on the UNFCCC negotiations, in which the positions of all participating governments were collected by hand-coding protocols from the negotiations as well as expert interviews with negotiators