Potassium Release Research Articles

Analysis of the Potassium-Solubilizing Priestia megaterium Strain NK851 and Its Potassium Feldspar-Binding Proteins.

Potassium-solubilizing bacteria are an important microbial group that play a critical role in releasing mineral potassium from potassium-containing minerals, e.g., potassium feldspar. Their application may reduce eutrophication caused by overused potassium fertilizers and facilitate plants to utilize environmental potassium. In this study, a high-efficiency potassium-solubilizing bacterium, named NK851, was isolated from the Astragalus sinicus rhizosphere soil. This bacterium can grow in the medium with potassium feldspar as the sole potassium source, releasing 157 mg/L and 222 mg/L potassium after 3 days and 5 days of incubation, respectively. 16S rDNA sequencing and cluster analysis showed that this strain belongs to Priestia megaterium. Genome sequencing further revealed that this strain has a genome length of 5,305,142 bp, encoding 5473 genes. Among them, abundant genes are related to potassium decomposition and utilization, e.g., the genes involved in adherence to mineral potassium, potassium release, and intracellular trafficking. Moreover, the strong potassium-releasing capacity of NK851 is not attributed to the acidic pH but is attributed to the extracellular potassium feldspar-binding proteins, such as the elongation factor TU and the enolase that contains potassium feldspar-binding cavities. This study provides new information for exploration of the bacterium-mediated potassium solubilization mechanisms.

Preparation, Features, and Efficiency of Nanocomposite Fertilisers Based on Glauconite and Ammonium Dihydrogen Phosphate.

This paper studies the chemical and mechanochemical preparation of glauconite with ammonium dihydrogen phosphate (ADP) nanocomposites with a ratio of 9:1 in the vol.% and wt.%, respectively. The methods include X-ray diffraction analysis, scanning electron microscope with energy-dispersive X-ray spectroscopy, transmission electron microscopy, infrared spectroscopy, and differential thermal analysis with a quadruple mass spectrometer. The manufactured nanocomposites keep the flaky glauconite structure. Some glauconite unit structures have been thickened due to minimal nitrogen (ammonium) intercalation into the interlayer space. The globular, granular, or pellet mineral particles of nanocomposites can be preserved via chemical techniques. Globular and micro-aggregate particles in nanocomposites comprise a thin film of adsorbed ADP. The two-step mechanochemical method makes it possible to slightly increase the proportion of adsorbed (up to 3.2%) and intercalated (up to 6.0%) nutrients versus chemical ways. Nanocomposites prepared via chemical methods consist of glauconite (90%), adsorbed (1.8-3.6%), and intercalated (3.0-3.7%) substances of ADP. Through the use of a potassium-containing clay mineral as an inhibitor, nitrogen, phosphorus, and potassium (NPK), nanocomposite fertilisers of controlled action were obtained. Targeted and controlled release of nutrients such as phosphate, ammonium, and potassium are expected due to various forms of nutrients on the surface, in the micropores, and in the interlayer space of glauconite. This is confirmed via the stepwise dynamics of the release of ammonium, nitrate, potassium, and phosphate from their created nanocomposites. These features of nanocomposites contribute to the stimulation of plant growth and development when fertilisers are applied to the soil.

Visual screening of potassium solubilizing bacteria for increasing the solubilization of potassium minerals

Research on potassium solubilizing bacteria (KSB) has recently gained attention, most of it has been focused on the size of the halo zone; however, information regarding KSB growth duration and their potential to reduce the use of chemical fertilizers for sustainable agriculture and to be used as a biofertilizer are still lacking. The aim of this study was to offer a complete, long-term observation of KSB growth. We monitored the growth of two KSB strains that were isolated from the rhizosphere for 7 days on Modified Aleksandrov Medium (MAM) plates. We specifically designed the observation times. These methods were used to distinguish KSB’s capability to solubilize potassium minerals. The results indicated that KSB-12 isolate was capable of producing organic acid and thus solubilizing potassium faster than KSB-19 isolate at 1-4 days of incubation. Interestingly, the solubilizing zone of the KSB-12 isolate decrease after 5 days of incubation, while KSB-19 isolate continued to grow, maintain cell numbers, produce organic acids, and continuously release potassium. Different types of volatile and non-volatile organic acids have an effect on this phenomenon. In conclusion, we provided a well-designed time series study regarding the potassium solubilization efficiency of KSB, determining the fastest and longest strains of potential KSBs.

Decomposition and nutrient release of green manure biomass in a passion fruit orchard in the brazilian semiarid region.

Green manure decomposition and nutrient recycling improve soil quality and productivity of different crops, but information on irrigated fruit orchards in the Brazilian semi-arid region is still scarce. Decomposition and nitrogen, phosphate, and potassium release from the cut biomass of three green manure legumes (sunn hemp, pigeon pea and jack bean) placed in litterbags, and spontaneous vegetation grown for 90 days in the rows of a passion fruit orchard were followed for 150 days. Biomasses decreased exponentially, reaching 12 (sunn hemp) to 25% (jack beans and spontaneous vegetation) after 150 days. K was rapidly released (< 21 and 4% of the original content remaining after 7 and 150 days, respectively), contrasting with more than half of the P and one third of the N remaining after 150 days. The amounts released were more influenced by the amounts of biomass produced (sunn hemp, 1583); (Jack bean 5152 kg ha-1); (Pigeon pea 822 kg ha-1); (Spontaneous plants 3175 kg ha-1); (spontaneous legumes 744 kg ha-1) than by variation in decomposition proportions among species. N release represented a liquid input to the soil, since more than 80% of the green manure and spontaneous vegetation contents came from N2-symbiotic fixation. Therefore, green manure is an effective technique to incorporate N and recycle K and P in irrigated orchards in the Brazilian semi-arid region.

Endophytic bacterial communities in wild rice (Oryza officinalis) and their plant growth-promoting effects on perennial rice.

Endophytic bacterial microbiomes of plants contribute to the physiological health of the host and its adaptive evolution and stress tolerance. Wild rice possesses enriched endophytic bacteria diversity, which is a potential resource for sustainable agriculture. Oryza officinalis is a unique perennial wild rice species in China with rich genetic resources. However, endophytic bacterial communities of this species and their plant growth-promoting (PGP) traits remain largely unknown. In this study, endophytic bacteria in the root, stem, and leaf tissues of O. officinalis were characterized using 16S rRNA gene Illumina sequencing. Culturable bacterial endophytes were also isolated from O. officinalis tissues and characterized for their PGP traits. The microbiome analysis showed a more complex structure and powerful function of the endophytic bacterial community in roots compared with those in other tissue compartments. Each compartment had its specific endophytic bacterial biomarkers, including Desulfomonile and Ruminiclostridium for roots; Lactobacillus, Acinetobacter, Cutibacterium and Dechloromonas for stems; and Stenotrophomonas, Chryseobacterium, Achromobacter and Methylobacterium for leaves. A total of 96 endophytic bacterial strains with PGP traits of phosphate solubilization, potassium release, nitrogen fixation, 1-aminocyclopropane-1-carboxylate (ACC) deaminase secretion, and siderophore or indole-3-acetic acid (IAA) production were isolated from O. officinalis. Among them, 11 strains identified as Enterobacter mori, E. ludwigii, E. cloacae, Bacillus amyloliquefaciens, B. siamensis, Pseudomonas rhodesiae and Kosakonia oryzae were selected for inoculation of perennial rice based on their IAA production traits. These strains showed promising PGP effects on perennial rice seedlings. They promoted plants to form a strong root system, stimulate biomass accumulation, and increase chlorophyll content and nitrogen uptake, which could fulfil the ecologically sustainable cultivation model of perennial rice. These results provide insights into the bacterial endosphere of O. officinalis and its application potential in perennial rice. There is the prospect of mining beneficial endophytic bacteria from wild rice species, which could rewild the microbiome of cultivated rice varieties and promote their growth.

Development and Evaluation of Buccal Mucoadhesive patches of Losartan Potassium

Buccal mucoadhesive patches of losartan potassium were formulated using hydroxypropyl methyl cellulose grades - K4M, K15M, K50M and Eudragit L100 polymers by the method of solvent casting. The prepared formulations were characterized for mechanical and physicochemical parameters like thickness, surface pH, uniformity of weight, swelling index, folding endurance, percentage moisture loss, drug content, in vitro dispersion and in vitro residence time. Further, in vitro drug release study was performed with the use of freshly prepared egg membrane as the semi-permeable membrane. The best formulation (F6) exhibited higher percentage of drug release 97.26%±0.41 at the end of 8 h. The sustained release of losartan potassium was found to be attained up to 8 h duration.

Synthesis and surface morphology of banana biochar-based nano-fertilizer and its effect on first stages of growth parameters of cucumber, broccoli, and red okra

Smart agro-practices over the years have revolutionized the agriculture sector and promoted the concept of sustainable agriculture. One such practice is use of agro-waste biochar in agricultural, environmental, and climatic operations. The viability of using a biochar-based nanocomposite as a support fertilizer for the gradual release of nitrogen, potassium, and phosphorus in various media is examined in this study. The banana peel biochar (BPBC) and its nanocomposite (BNF) were prepared using a simple yet comprehensive chemical process. Synthesized materials were evaluated using FT-IR and SEM/EDX. Physical attributes as well as fertilizer basic characteristics were determined and prepared nanocomposite demonstrated noticeably better water absorbance ratio (68%), equilibrium water content (78.97%), and swelling ratio (3.64 g g−1) than biochar, which is advantageous for preserving soil water levels. The salt index values (0.087mmhos/cc) of the created nanocomposite performed better when compared to the conventional fertilizers due to their safer application. Long-term availability of all doped minerals to the plants, during experimental cycle, was revealed by slow-release nutrient studies in water and soil, which is ideal for promoting germination and growth. The findings of this research revealed that prepared BNF showed improved germination parameters i.e., time for 50% germination (3.4, 3.3, 4.4 days), germination index (3.1, 3.5, 2.4), final germination percentage (91.7, 100, 83.3%), mean germination time (4.0, 3.9, 4.9 days), for cucumber, broccoli and okra, respectively. In addition to that the prepared BNF facilitated enhanced shoot and root length in all the three vegetables as compared to conventional fertilizers. The dose optimization studies depicted that best results of germination as well as plant growth parameters are facilitated by BNF (37.5 kg/ha) owing to enhancement in soil quality by supplying additional organic matter in addition to provision of nutrients on slow-release.

PATTERN OF POTASSIUM RELEASE FROM SLOW RELEASE FERTILIZER POTASSIUM CLORIDE-BENTONITE FERTILIZER

Potassium has an important role in the process of plant growth, but its presence and availability in the soil are limited, because potassium is easily lost and flows out by water. Increasing the efficiency of potassium fertilization can be pursued through the formulation of fertilizer in the form of slow-release fertilizer (SRF) using bentonite. This study aimed to determine the release of potassium in potassium chloride fertilizer into the soil after bonding with acid-activated bentonite coated with potassium chloride. The composition of the KCl fertilizer made varies with bentonite with a mass ratio (g) of 1:1; 2:1; 3:1; 4:1; and 5:1, with a percolation time of 28 days. The concentration of released potassium was determined using an atomic absorption spectrophotometer. Material characterization was carried out by FTIR. The results showed that the ratio 1:3 had the highest potassium content of 45.12% with an incubation time of 28 days. The concentration of released potassium on day 7; 14; 21; and 28 respectively (12.55±1.25)%, (28.39±1.49)%, (5.,91±0.98)%, and (70.49±1.36)% . The results of the characterization of the determination of the fungal group on SRF3 were not significantly different from that of activated bentonite. Even though there were differences in the intensity of certain peaks and changed the functional groups.

Characterizing potassium release under turbulent conditions during biomass stream combustion: A comparative analysis of different pretreatments

The release rate of potassium during biomass combustion significantly influences slagging, fouling, and corrosion in industrial equipment. Given that dispersed biomass stream combustion predominantly occurs under turbulent ambient conditions, we investigate the combustion characteristics and potassium release behavior of rice husk and its derived fuels (water-washed, torrefied, and char) under high-turbulent conditions in a tubular flame burner (TFB). Tunable diode laser absorption spectroscopy (TDLAS) technology, combined with high-speed imaging, was employed to online monitor the release of atomic potassium (K(g)) and the ignition characteristics of biomass stream combustion. The results showed that the rice husk stream followed a joint hetero-homogeneous ignition mechanism, whereas the biochar stream underwent heterogeneous ignition in the TFB. The K(g) peak, occurring ahead of the maximum spontaneous radiation position, was observed at approximately 25 mm from the injectors, with a concentration of 0.067 ppmv during rice husk stream combustion. In contrast, the peak K(g) concentrations for biochar and torrefied rice husk were delayed, reaching 0.026 ppmv and 0.021 ppmv, respectively, compared to the raw biomass samples combusted in the TFB. Distinct differences in activation energy for K(g) release were identified, with pulverized rice husk exhibiting the lowest activation energy (75.53 kJ/mol) and rice husk-char showing the highest (94.20 kJ/mol).

A semi purified hydroalcoholic fraction from Caesalpinia bonduc seeds causes ergosterol biosynthesis inhibition in Candida albicans resulting in cell membrane damage.

Candida species are currently developing resistance to prevailing commercially available drugs, which raises an instantaneous need to discover novel antifungals. To cope with this shocking situation, phytochemicals are the richest, safest, and most potent source of excellent antimicrobials with broad-spectrum activity. The aim of the current study is to explore the anticandidal potential of the various fractions purified from the hydroalcoholic extract of C. bonduc seed. Out of five fractions purified from the hydroalcoholic extract, fraction 3 (Fr. 3) recorded the best activity against C. albicans (8μg/mL) and thus this species was chosen for further mechanism of action studies. The phytochemical examination reveals that Fr. 3 was found to contain steroids and triterpenoids. This was further supported by LC-QTOF-MS and GCMS analyses. Our findings show that Fr. 3 targets the ergosterol biosynthesis pathway in C. albicans by inhibiting the lanosterol 14-α demethylase enzyme and downregulating expression of its related gene ERG11. Molecular docking outcomes disclosed favorable structural dynamics of the compounds, implying that the compounds present in Fr. 3 would be able to successfully bind to the lanosterol 14-α demethylase, as evidenced by the docked compounds' strong interaction with the target enzyme's amino acid residues. Considering virulence factors, the Fr. 3 recorded significant antibiofilm activity as well as germ-tube reduction potential. Furthermore, Fr. 3 enhances the production of intracellular reactive oxygen species (ROS). This suggests that the antifungal activity of Fr. 3 was associated with membrane damage and the induction of ROS production, resulting in cell death. Fluorescence microscopic analysis of PI stained Candida further showed changes in the plasma membrane permeability, which causes severe loss of intracellular material and osmotic balance. This was demonstrated by the potassium ion leakage and release of genetic materials. Finally, the erythrocyte lysis assay confirmed the low cytotoxicity of Fr. 3. Both in silico and in vitro results suggest that Fr. 3 has the potential to propel forward novel antifungal drug discovery programmes.

Non-exchangeable potassium release and supplying power of soils of Haryana, Northwest India

The management of potassium (K) necessitates the understanding of K dynamics and assessment of crop-available K reserves. Non-exchangeable K (NeK) could have a substantial impact on plant nutrition, therefore, non-exchangeable potassium release and supplying power of soils from four different soil orders of Haryana, Northwest India was examined. After successive cropping with maize and oats, initial exchangeable K contents of 0.38, 0.22, 0.25 and 0.09 cmol(p+) kg−1 declined by 23.37%, 27.28%, 29.41% and 27.77% in Alfisols, Inceptisols, Entisols and Aridisols, respectively. The release of non-exchangeable K to plant roots in screen house was compared with K release to nitric, citric and oxalic acids in the laboratory to assess the feasibility of these acids for non-exchangeable K extraction. The amount of K released was quantified as cumulative uptake by maize and oats. Non-exchangeable K released to plant roots (r = 0.94; p ≤ 0.01) and oxalic acid (r = 0.63; p ≤ 0.05) were significantly correlated with cumulative K uptake. The initial level of exchangeable K (Ex-K) and cumulative K uptake by maize and oats exhibited strong and significant correlation (r = 0.85; p ≤ 0.05) signifying that K removal by crops results in the equilibrium among different K pools. The strongly significant relationship between non-exchangeable K released to oxalic acid and plant roots (r = 0.92; p ≤ 0.01) affirms the reliability of laboratory methods vis-à-vis K release studies.

Effect of Crop Residue Incorporation and Potassium Releasing Bacteria (KRB) onPotassium Fractions and Yield of Maize (Zea mays L.)

Effect of Crop Residue Incorporation and Potassium Releasing Bacteria (KRB) onPotassium Fractions and Yield of Maize (Zea mays L.)

Idealized multiple-timescale model of cortical spreading depolarization initiation and pre-epileptic hyperexcitability caused by NaV1.1/SCN1A mutations.

NaV1.1 (SCN1A) is a voltage-gated sodium channel mainly expressed in GABAergic neurons. Loss of function mutations of NaV1.1 lead to epileptic disorders, while gain of function mutations cause a migraine in which cortical spreading depolarizations (CSDs) are involved. It is still debated how these opposite effects initiate two different manifestations of neuronal hyperactivity: epileptic seizures and CSD. To investigate this question, we previously built a conductance-based model of two neurons (GABAergic and pyramidal), with dynamic ion concentrations (Lemaire et al. in PLoS Comput Biol 17(7):e1009239, 2021. https://doi.org/10.1371/journal.pcbi.1009239 ). When implementing either NaV1.1 migraine or epileptogenic mutations, ion concentration modifications acted as slow processes driving the system to the corresponding pathological firing regime. However, the large dimensionality of the model complicated the exploitation of its implicit multi-timescale structure. Here, we substantially simplify our biophysical model to a minimal version more suitable for bifurcation analysis. The explicit timescale separation allows us to apply slow-fast theory, where slow variables are treated as parameters in the fast singular limit. In this setting, we reproduce both pathological transitions as dynamic bifurcations in the full system. In the epilepsy condition, we shift the spike-terminating bifurcation to lower inputs for the GABAergic neuron, to model an increased susceptibility to depolarization block. The resulting failure of synaptic inhibition triggers hyperactivity of the pyramidal neuron. In the migraine scenario, spiking-induced release of potassium leads to the abrupt increase of the extracellular potassium concentration. This causes a dynamic spike-terminating bifurcation of both neurons, which we interpret as CSD initiation.

The Effect of Polymers Ratio Carboxymethyl Chitosan, Polyvinyl Pyrolidone K-30, and Ethyl Cellulose N22 on Physico-Chemical Characteristics and Drug Release from Matrix Type Diclofenac Potassium Patch

Background: Diclofenac potassium is an NSAID drug that is used in the treatment of mild to moderate pain. The use of this drug orally can cause side effects in the gastrointestinal tract, and the drug will undergo extensive first-pass metabolism in the liver. Therefore, preparations for transdermal patches were made. Objective: Determining the effect of the polymer ratios of carboxymethyl chitosan, polyvinyl pyrolidone K-30, and ethyl cellulose N22 on the physicochemical characteristics and drug release of a matrix type diclofenac potassium patch. Methods: In this study, matrix type diclofenac potassium patches were made using a combination of carboxymethyl chitosan (CMC), polyvinyl pyrrolidone (PVP) K-30 polymer, and ethyl cellulose (EC) N22 in a ratio of 2:3:7 and 3:2:7. Patches are made by mixing the entire polymer matrix and diclofenac potassium together, which are then evaporated and dried. Results: The results showed that the different polymer compositions of CMC, PVP K-30, and EC N22 resulted in patches with physicochemical characteristics that were not significantly different. The combination of these polymers is able to control the release of the drug from the patch for a long time. It was also found that increasing the concentration of CMC was able to increase the rate of release of diclofenac potassium. Formula 2 with a ratio of 3:2:7 is claimed to be the best formula in terms of physical, chemical, and drug release characteristics from the patch. Further studies are needed, such as drug penetration tests into the skin.

Production of potassium-enriched biochar from Canna indica: Transformation and release of potassium

Potassium (K) is one of the essential macronutrients for plant growth, while most agricultural soils are suffering from K deficiency worldwide. Therefore, it is a promising strategy to prepare K-enriched biochar from biomass waste. In this study, various K-enriched biochars were prepared from Canna indica at 300–700 °C by pyrolysis, co-pyrolysis with bentonite, and pelletizing-co-pyrolysis. The chemical speciation and release behaviors of K were investigated. The derived biochars showed high yields, pH values, and mineral contents, which were affected by the pyrolysis temperatures and techniques. The derived biochars contained a significant amount of K (161.3–235.7 mg/g), which was much higher than the biochars derived from agricultural residues and wood. Water-soluble K was the dominant K species in biochars with a proportion of 92.7–96.0%, and co-pyrolysis and pelletizing promoted the transformation of K to the exchangeable K and K silicates. In comparison with the C. indica derived biochars (83.3–98.0%), the bentonite-modified biochar showed a lower cumulative release proportion of K (72.5% and 72.6%) in a 28-day release test, meeting the Chinese National Standard for slow-release fertilizers. In addition, the pseudo-first order, pseudo-second order, and Elovich models well described the K release data of the powdery biochars, and the pseudo-second order model was the best fit for the biochar pellets. The modeling results indicated that the K release rate decreased after the addition of bentonite and pelletizing. These results indicated that the biochars derived from C. indica could be used as potential slow-release K fertilizers for agricultural application.

Release Pattern of Nitrogen and Potassium from Controlled Release Fertilizer (CRF) in the Soil

Nitrogen (N) and potassium (K) are macronutrients that plants need for better growth and yield. However, they are readily lost from the soil through volatilization, denitrification, and leaching, aside from being absorbed by plant roots. Thus, a Controlled Release Fertilizer (CRF) may be formulated and applied to maximize the beneficial effects of N and K fertilization. This study aimed to describe the release pattern of ammonium nitrogen (NH4 -N), nitrate nitrogen (NO3 -N), and K from CRF through the laboratory incubation method. Two types of CRF - CRF A (16-16-16) and CRF B (30-6-8), with a non-CRF (Mutiara NPK16-16-16) as Control – were used. Each fertilizer was tested at 600 and 1200 kg ha-1 doses. The results showed that the NH4 -N release was very high at 40 – 60% but declined to almost 0% after 14 weeks. The NO3 -N release rate was 17 – 40% during the first week, followed by a steady increase to nearly 100% by the 14th incubation week. Potassium release ranged from 20% to 30% in the first week, then rose to 30 – 70% at Week 14. Overall, CRF (30-6-8) at a dose of 1200 kg ha-1 showed the slowest rate of nitrogen release.

Development of Fast Dissolving Tablets of Losartan Potassium using Novel Co-processed Superdisintegrants

Losartan is used to treat high blood pressure (hypertension) and also used to lower the risk of stroke in certain people with heart disease. Therefore, the purpose of this study is to formulate mouth dissolving tablet of losartan potassium to improve its bioavailability, to attain fast onset of action and rise patient compliance. Owing to short bioavailability of 33% and to increase onset of action, fast dissolving tablets of Losartan Potassium were formulated using coprocessed superdisintegrants in order to improve the dissolution rate, in that way the bioavailability. The effect of concentration of the Croscarmellose sodium was studied by a set of three formulations (F1, F2, F3) with concentrations of 2%, 4% and 8% w/w respectively. Similarly, the impact of Sodium Starch Glycolate was studied by a set of three formulations (F4, F5 and F6) respectively. The formulation prepared with 8% w/w of superdisintegrant showed relatively rapid release of Losartan potassium when compared with other concentrations of Croscarmellose sodium and Sodium Starch Glycolate. The formulation prepared with Croscarmellose sodium had showed relatively fast release of Losartan Potassium when compared with Sodium Starch Glycolate. Three formulations (F7, F8 and F9) were prepared by including a combination of superdisintegrants (Co-processed Mixtures), Croscarmellose sodium and Sodium Starch Glycolate by direct compression method. Formulation containing Co-processed mixtures had less disintegration time as compared to the individual superdisintegrants. Subsequently, we can conclude that nature, concentration of the superdisintegrant in addition to combination of superdisintegrants (Co-processed) showed influence on the rate of dissolution.

Simulation of Potassium Availability in the Application of Biochar in Agricultural Soil

Nutrient availability after fertilising agricultural soils is affected by many factors, including soil moisture conditions and physicochemical properties. Herein, the availability of potassium in soil enriched with biochar is studied, considering either saturated or unsaturated moisture conditions and questioning key ion exchange approaches, such as equilibrium exchange (E.E.) and kinetic exchange (K.E.). Potassium release is simulated from a soil–biochar mixture of 0, 0.5, 1 and 2% by coupling HYDRUS-1D and PHREEQC models. The water flow, mass transport and geochemical processes are simulated for a cultivation period that imitates agronomic and environmental conditions of a common agricultural field in Northern Greece. Potassium is released gradually during the irrigation period in the case of unsaturated flow conditions as opposed to its complete release over a few days in the case of saturated flow conditions in the soil. Regarding ion-exchange processes, the soluble amount of potassium is more readily available for transport in soil solution when using the E.E. approach compared to the K.E. approach that assumes a kinetically controlled release due to interactions occurring at the solid–solution interface. The increased proportion of biochar in soil results in a doubling of available potassium. Among the four modelling schemes, although the total mass of potassium released into soil solution is similar, there is a significant variation in release time, indicating that simplified saturated conditions may lead to unrealistic estimates of nutrient availability. Further experimental work will be valuable to decrease the uncertainty of model parameter estimation in the K.E. approach.

Multi-component cord blood banking: a proof-of-concept international exercise.

Most public cord blood (CB) banks currently discard more than 80% of umbilical CB units not suitable for hemopoietic stem cell transplant due to low stem cell count. Although CB platelets, plasma, and red blood cells have been used for experimental allogeneic applications in wound healing, corneal ulcer treatment, and neonatal transfusion, no standard procedures for their preparation have been defined internationally. A network of 12 public CB banks in Spain, Italy, Greece, the UK, and Singapore developed a protocol to validate a procedure for the routine production of CB platelet concentrate (CB-PC), CB platelet-poor plasma (CB-PPP), and CB leukoreduced red blood cells (CB-LR-RBC) using locally available equipment and the commercial BioNest ABC and EF medical devices. CB units with >50 mL volume (excluding anticoagulant) and ≥150×109/L platelets were double centrifuged to obtain CB-PC, CB-PPP, and CB-RBC. The CB-RBC were diluted with saline-adenine-glucose-mannitol (SAGM), leukoreduced by filtration, stored at 2-6°C, and tested for hemolysis and potassium (K+) release over 15 days, with gamma irradiation performed on day 14. A set of acceptance criteria was pre-defined. This was for CB-PC: volume ≥5 mL and platelet count 800-1,200×109/L; for CB-PPP: platelet count <50×109/L; and for CB-LR-RBC: volume ≥20 mL, hematocrit 55-65%, residual leukocytes <0.2×106/unit, and hemolysis ≤0.8%. Eight CB banks completed the validation exercise. Compliance with acceptance criteria was 99% for minimum volume and 86.1% for platelet count in CB-PC, and 90% for platelet count in CB-PPP. Compliance in CB-LR-RBC was 85.7% for minimum volume, 98.9% for residual leukocytes, and 90% for hematocrit. Compliance for hemolysis ≤0.8% decreased from 89.0 to 63.2% from day 0 to 15. K+ release increased from 3.0±1.8 to 25.0±7.0 mmol/L from day 0 to 15, respectively. The MultiCord12 protocol was a useful tool to develop preliminary standardization of CB-PC, CB-PPP, and CB-LR-RBC.

Release mechanism of impurity potassium in molybdenum concentrate treatment process

AbstractThe kinetic characteristics and mechanism of potassium release in the molybdenum concentrate treatment process were studied by kinetic analysis and analytical techniques such as SEM−EDS, MLA and ICP. The results show that the first-order kinetic model is the best kinetic model of potassium release in the water washing and ammonia leaching process. Potassium is present in molybdenum concentrate in the form of soluble potassium ions and four potassium minerals. During the roasting process of molybdenum concentrate, some muscovite decomposed into orthoclase, while other muscovite combined with impurity metal elements to form anandite. Furthermore, the transformation of muscovite to orthoclase could be effectively inhibited by the rapid cooling of molybdenum calcine. The results could provide a basis for reducing potassium content in ammonium molybdate products.