749,188 research outputs found
Use of potassium polyaspartate for the tartaric stabilization of Sicilian white wines
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)
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
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Efficacy and safety of sodium zirconium cyclosilicate in patients with baseline serum potassium level ≥ 5.5 mmol/L: pooled analysis from two phase 3 trials.
BackgroundReliable, timely-onset, oral treatments with an acceptable safety profile for patients with hyperkalemia are needed. We examined the efficacy and safety of sodium zirconium cyclosilicate (SZC; formerly ZS-9) treatment for ≤ 48 h in patients with baseline serum potassium level ≥ 5.5 mmol/L.MethodsData were pooled from two phase 3 studies (ZS-003 and HARMONIZE) among patients receiving SZC 10 g three times daily. Outcomes included mean and absolute change from baseline, median time to potassium level ≤ 5.5 and ≤ 5.0 mmol/L, and proportion achieving potassium level ≤ 5.5 and ≤ 5.0 mmol/L at 4, 24, and 48 h. Outcomes were stratified by baseline potassium. Safety outcomes were evaluated.ResultsAt baseline, 125 of 170 patients (73.5%) had potassium level 5.5-< 6.0, 39 (22.9%) had potassium level 6.0-6.5, and 6 (3.5%) had potassium level > 6.5 mmol/L. Regardless of baseline potassium, mean potassium decreased at 1 h post-initial dose. By 4 and 48 h, 37.5% and 85.0% of patients achieved potassium level ≤ 5.0 mmol/L, respectively. Median (95% confidence interval) times to potassium level ≤ 5.5 and ≤ 5.0 mmol/L were 2.0 (1.1-2.0) and 21.6 (4.1-22.4) h, respectively. Fifteen patients (8.8%) experienced adverse events; none were serious.ConclusionsSZC 10 g three times daily achieved serum potassium reduction and normokalemia, with a favorable safety profile.Trial registrationClinicalTrials.gov identifiers: ZS-003: NCT01737697 and HARMONIZE: NCT02088073
Research of Influence of Potassium-rich Diets on the Physical Performance of Students
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)
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
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
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
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Proton block and voltage gating are potassium-dependent in the cardiac leak channel Kcnk3.
Potassium leak conductances were recently revealed to exist as independent molecular entities. Here, the genomic structure, cardiac localization, and biophysical properties of a murine example are considered. Kcnk3 subunits have two pore-forming P domains and unique functional attributes. At steady state, Kcnk3 channels behave like open, potassium-selective, transmembrane holes that are inhibited by physiological levels of proton. With voltage steps, Kcnk3 channels open and close in two phases, one appears to be immediate and one is time-dependent (tau = approximately 5 ms). Both proton block and gating are potassium-sensitive; this produces an anomalous increase in outward flux as external potassium levels rise because of decreased proton block. Single Kcnk3 channels open across the physiological voltage range; hence they are "leak" conductances; however, they open only briefly and rarely even after exposure to agents that activate other potassium channels
EFFECTS of FOUR RATES of THREE NITROGEN SOURCES on YIELD and CHEMICAL COMPOSITION of MANCHAR BROMEGRASS FORAGE in the MATANUSKA VALLEY
Paper copies available in Archives, Acc# 2013-0059List of Tables -- List of Figures -- Summary --Introduction -- Experimental Procedure -- Results and Discussion: Yield, Nitrogen Percentage, Nitrogen Uptake, Nitrogen Recovery, Phosphorus Percentages, Phosphorus Uptake, Phosphorus Recover, Potassium Percentages, Potassium Uptake, Potassium Recovery, Calcium Percentages, Calcium Uptake, Magnesium Percentages, Magnesium Uptake, Sodium Percentages and Uptake, Aluminum, Barium, Boron, Chromium, Copper, Iron, Manganese, Molybdenum, Strontium, Zinc -- Acknowledgment -- Literature Cite
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