State of the art and future research directions of materials science applied to electrochemical biosensor developments

Centralized laboratories in which analytical processes are automated to enable the analysis of large numbers of samples at relatively low cost are used for analytical testing throughout the world. However, healthcare is changing, partly due to the general recognition that care needs to be more patient-centered and putting the patient at the center of action. One way to achieve this goal is to consider point-of-care testing (PoC) devices as alternative analytical concepts. This requires miniaturization of current analytical concepts and the use of cost-effective diagnostic tools with appropriate sensitivity and specificity. Electrochemical sensors are ideally adapted as they provide robust, low-cost, and miniaturized solutions for the detection of variable analytes, yet lack the high sensitivity comparable to more classical diagnosis approaches. Advances in nanotechnology have opened up a plethora of different nanomaterials to be applied as electrode and/or sensing materials in electrochemical biosensors. The choice of materials significantly influences the sensor's sensitivity, selectivity, and overall performance. A critical review of the state of the art with respect to the development of the utilized materials (between 2019 and 2023) and where the field is heading to are the focus of this article.

Influence of animal and plant fat addition in pasture and winter feeding of high yielding cows at first stage of lactation on productivity and physiological profiles

200 g of fat in the form of greased wheat bran, was given cows during pasture feeding. For winter feeding on hay and silages the amount was 400 g of greased wheat bran or 400 g of oil in ground rapeseed per day and per animal. Influence of the fat addition on the yield and milk composition was observed in the case of pasture experiment. No such influence was observed in the winter feeding. Addition of fat advantageously influenced the chemical constituents in the cow blood in both experiments.

Utilization of nitrite and nitrate by dwarf bean

The uptake and conversion of NO 2 (-) and the effect of NO 2 (-) on the uptake and reduction of NO 3 (-) were examined in N-depleted Phaseolus vulgaris L. Nitrite uptake at 0.1 mmol dm(-3) was against an electrochemical gradient and became constant after one or two initial phases. Steadystate uptake declined with increasing ambient NO 2 (-) concentration (0-0.7 mmol dm(-3)). In this concentration range root oxygen consumption was unaffected by NO 2 (-) , indicating that the decrease of NO 2 (-) uptake was not related to respiration. After 6 h NO 2 (-) supply, about one-third of the absorbed NO 2 (-) had accumulated, mainly in the root system. Oxidation of NO 2 (-) to NO 3 (-) was not observed. The apparent induction period for NO 3 (-) uptake was about 6 h in control plants and 3.5 h in plants that were pretreated for 18 h with NO 2 (-) . In contrast, the time course of NO 2 (-) uptake was unaffected by pretreatment with NO 3 (-) . Steadystate NO 3 (-) uptake was less affected by NO 2 (-) than was steady-state NO 2 (-) uptake by NO 3 (-) . Nitrate reductase activity (NRA) in leaves and roots was induced by both NO 3 (-) and NO 2 (-) . In roots, induction with NO 2 (-) was faster than with NO 3 (-) , but there was no difference in NRA after 5 h. Nitrite inhibited NRA in the roots of NO 3 (-) -induced plants and thus seems to stimulate the induction, but not the activity of induced nitrate reductase. In view of the observed differences in time course and mutual competition, a common uptake mechanism for NO 2 (-) and NO 3 (-) seems unlikely. Expression of the NO 2 (-) effect on the induction of NO 3 (-) uptake required more time than the induction itself. We therefore conclude that NO 2 (-) is not the physiological inducer of NO 3 (-) uptake.