Iron Porphyrin Allows Fast and Selective Electrocatalytic Conversion of CO2 to CO in a Flow Cell.

Molecular catalysts have been shown to have high selectivity for CO2 electrochemical reduction to CO, but with current densities significantly below those obtained with solid-state materials. By depositing a simple Fe porphyrin mixed with carbon black onto a carbon paper support, it was possible to obtain a catalytic material that could be used in a flow cell for fast and selective conversion of CO2 to CO. At neutral pH (7.3) a current density as high as 83.7 mA cm-2 was obtained with a CO selectivity close to 98 %. In basic solution (pH 14), a current density of 27 mA cm-2 was maintained for 24 h with 99.7 % selectivity for CO at only 50 mV overpotential, leading to a record energy efficiency of 71 %. In addition, a current density for CO production as high as 152 mA cm-2 (>98 % selectivity) was obtained at a low overpotential of 470 mV, outperforming state-of-the-art noble metal based catalysts.

Process of measuring in clinical medicine--implications of different definitions in clinical therapeutic studies.

Often, the decision whether a patient can be considered as healthy or ill is very difficult and depends on measurements and the interpretation of the results. Therefore, it is necessary to build and establish devices that base on certain pre-considerations (who should assess the data, when and how should be measured). Additionally, these devices have to be valid, reliable and responsive. According to the literature we came to the conclusion that no uniform definition of what is 'healthy' exists. Referring to mathematical considerations we show an approach to solve this problem especially when the device is a scale. Based on the quality of the scale and of certain pre-considerations, normal ranges can be established that will help to distinguish whether patients are 'healthy' or 'ill'. In this short review we discuss the problem of the establishment of a cut-off level on the basis of devices and we try to point out a solution to solve the arising problems.

Process of measuring in clinical medicine--implications of different definitions in clinical therapeutic studies.

Often, the decision whether a patient can be considered as healthy or ill is very difficult and depends on measurements and the interpretation of the results. Therefore, it is necessary to build and establish devices that base on certain pre-considerations (who should assess the data, when and how should be measured). Additionally, these devices have to be valid, reliable and responsive. According to the literature we came to the conclusion that no uniform definition of what is 'healthy' exists. Referring to mathematical considerations we show an approach to solve this problem especially when the device is a scale. Based on the quality of the scale and of certain pre-considerations normal ranges can be established that will help to distinguish whether patients are 'healthy' or 'ill'. In this short review we discuss the problem of the establishment of a cut-off level on the basis of devices and we try to point out a solution to solve the arising problems.