691,446 research outputs found

    Use of potassium polyaspartate for the tartaric stabilization of Sicilian white wines

    Get PDF
    Cold stabilization is a common method used to avoid tartaric acid crystals from forming in bottled wine, but this technique shows some inconveniences on the sensory characteristics and energy cost. In the present research, the tartaric stabilization in Sicilian white wines, with a recently permissible molecule in oenology, was studied: the potassium polyaspartate (PAK). The PAK has a negative charge at wine pH and allows to sequester the K+ cations; consequently it inhibits the formation and the growth of potassium bitartrate crystals. PAK is a relatively small polymer; perfectly microfiltrated and does not allow the filling phenomena in filtration membranes. The adding of PAK allowed to reduce almost all the tartaric precipitations on very unstable wines, regardless of the chemical-physical characteristics of the treated white wines. The stability of PAK, after thermal stress of the wine added to this polymer, was confirmed evaluating different analytical parameters such as pH, total acidity and buffer power, while variations in the conductivity of wines seemed to indicate a residual tartaric instability. In conclusion, the use of PAK makes possible to improve the sensory characteristics of wines, considering lower losses of tartaric acid and potassium, which are important for acid perception and acid persistence (buffer power), as well as reducing production costs and low environmental impact

    Serum potassium levels and outcome in acute heart failure (data from the PROTECT and COACH trials)

    Get PDF
    Serum potassium is routinely measured at admission for acute heart failure (AHF), but information on association with clinical variables and prognosis is limited. Potassium measurements at admission were available in 1,867 patients with AHF in the original cohort of 2,033 patients included in the Patients Hospitalized with acute heart failure and Volume Overload to Assess Treatment Effect on Congestion and Renal FuncTion trial. Patients were grouped according to low potassium (<3.5 mEq/l), normal potassium (3.5 to 5.0 mEq/l), and high potassium (>5.0 mEq/l) levels. Results were verified in a validation cohort of 1,023 patients. Mean age of patients was 71 – 11 years, and 66% were men. Low potassium was present in 115 patients (6%), normal potassium in 1,576 (84%), and high potassium in 176 (9%). Potassium levels increased during hospitalization (0.18 – 0.69 mEq/l). Patients with high potassium more often used angiotensin-converting enzyme inhibitors and mineralocorticoid receptor antagonists before admission, had impaired baseline renal function and a better diuretic response (p [ 0.005), independent of mineralocorticoid receptor antagonist usage. During 180-day follow-up, a total of 330 patients (18%) died. Potassium levels at admission showed a univariate linear association with mortality (hazard ratio [log] 2.36, 95% confidence interval 1.07 to 5.23; p [ 0.034) but not after multivariate adjustment. Changes of potassium levels during hospitalization or potassium levels at discharge were not associated with outcome after multivariate analysis. Results in the validation cohort were similar to the index cohort. In conclusion, high potassium levels at admission are associated with an impaired renal function but a better diuretic response. Changes in potassium levels are common, and overall levels increase during hospitalization. In conclusion, potassium levels at admission or its change during hospitalization are not associated with mortality after multivariate adjustment

    Research of Influence of Potassium-rich Diets on the Physical Performance of Students

    Full text link
    The aim of the work is the scientific substantiation and experimental support of the expedience and use of potassium-cationic water for improving the bread quality and the study of the influence of potassium-rich diets on the physical performance of students. There was studied the influence of potassium cations on the activity of proteolytic enzymes of wheat flour. It was established, that at using potassium-cationic water, the output of wet gluten (35,1 %) essentially increases, at that the output of dry one (8,4 %) decreases to the same extent that is a positive factor in the bakery technology. It was proved that enriching the vital medium of bakery yeast by potassium cations essentially activates their ability to hydrolysis of maltose that favors activation of the process of gassing (Maltase activity – 35,1 min). The process of gassing influences the speed of dough-conduction and ready bread quality, especially volume (357,7, 100 g/ml), porosity (79,1 %) and crumb ability to compression (33,5 c.u.). It was established, that consumption of bread, produced on potassium-cationic water, favors the strengthening of the heart muscle tone, improvement of the general condition of the organism, especially, physical endurance and performance

    Practical experience with the use of Baking Powder (potassium bicarbonate) for the control of Apple Scab (Venturia ineaqualis)

    Get PDF
    In small plot trials, performed by several institutes in the past years, potassium bicarbonate proved to be a promising alternative to the use of copper for the control of apple scab in organic orchards. Feasibility, effectiveness, consequences, and side effects of the replacement of copper by bicarbonate under practical conditions are largely unknown. In 2007 Five Dutch organic apple growers compared a bicarbonate based scab management strategy with their standard spray program. The use of 5 kg potassium bicarbonate + 2 kg. wettable sulphur shortly before rain or during infection development, was the core of the strategy. It was concluded that the control of apple scab with the potassium bicarbonate strategy was as effective as the standard spray plan, provided lime sulphur was available tot cover extreme situations. The applications did not lead to any phytotoxic damage on leafs or fruits. Potassium bicarbonate tank mixed with a Mn leaf fertilizer however resulted in severe leaf drop, and necrotic spots on the remaining leafs. The use of potassium bicarbonate did not increase the potassium content of the fruits

    Effects of cromakalim (BRL 34915) on potassium conductances in CA3 neurons of the guinea-pig hippocampus in vitro

    Get PDF
    The action of the potassium channel activator, cromakalim (BRL 34915), on membrane potential, input resistance and current-voltage-relationship of CA3 neurons in a slice preparation of the guinea-pig hippocampus was investigated by means of intracellular recordings. In the presence of tetrodotoxin, cromakalim (30–100 mol/l) produced a hyperpolarization up to 4 mV associated with a decrease in input resistance up to 10 MOhms. Determination of the equilibrium potential of the cromakalim action revealed that the hyperpolarization is due to the activation of a potassium conductance. This cromakalim-activated potassium conductance was voltage-dependent, i.e. it increased with hyperpolarization. Among a number of potassium channel blockers tested, only Cs+ (2 mmol/l) and Ba2+ (0.5 mmol/1) were able to inhibit the cromakalim-induced effects. Simultaneously, both cations suppressed the hyperpolarizing inward rectification (anomalous rectification) in these neurons, indicating that cromakalim activated or potentiated an inwardly rectifying potassium conductance. In addition, cromakalim slightly enhanced both amplitude and duration of afterhyperpolarizations following single calcium-dependent action potentials, suggesting that cromakalim might have a weak facilitatory effect on calcium-dependent potassium conductances

    Evidence for the formation of a Mott state in potassium-intercalated pentacene

    Get PDF
    We investigate electronic transport through pentacene thin-films intercalated with potassium. From temperature-dependent conductivity measurements we find that potassium-intercalated pentacene shows metallic behavior in a broad range of potassium concentrations. Surprisingly, the conductivity exhibits a re-entrance into an insulating state when the potassium concentration is increased past one atom per molecule. We analyze our observations theoretically by means of electronic structure calculations, and we conclude that the phenomenon originates from a Mott metal-insulator transition, driven by electron-electron interactions.Comment: 8 pages, 6 figure
    • …
    corecore