Extraction Of Am Research Articles

Extraction Behavior of Americium(III) in Benzoylpyrazolone Dissolved in Pyrrolidinium Based Ionic Liquid

Extraction of Am(III) from nitric acid medium was carried out in a solution of benzoylpyrazolone (HPMBP) dissolved in 1-butyl-1-methylpyrrolidinium bis(trifluoro-methanesulfonyl)imide ([C4mpyr][NTf2]) ionic liquid. The extraction behavior of Am(III) in ionic liquid phase was investigated as a function of various parameters, such as pH of aqueous phase, duration of equilibration, and concentration of ionic liquid and nitrate in aqueous phase. Appreciable extraction was obtained at low pH medium (< pH 2) unlike other diketone based extractant. Extraction of Am(III) in ionic liquid was compared with that observed in a molecular diluent, n-dodecane (n-DD) under similar experimental condition. Remarkably high distribution ratio was observed in IL medium as compared to n-DD medium. The slope analysis of the extraction data was carried out to evaluate the mechanistic aspects of extraction. Extraction mechanism was different from conventional molecular diluent. Recovery of americium from the loaded ionic liquid phase was also studied using nitric acid.

A novel solvent system containing a dipicolinamide in room temperature ionic liquids for actinide ion extraction

Solvent extraction of Am(III), Pu(IV) and Eu(III) was done from nitric acid medium using a solvent system containing a substituted dipicolinamide extractant dissolved in room temperature ionic liquid. The solvent system was found to be more efficient as compared to the previously reported solvents in molecular diluents.

Cytokine levels are associated with the severity of varicella infections.

Varicella is a highly contagious disease. Epidemics of varicella are seen every year globally and present a threat to public health, especially in China and other developing countries. Clinical and laboratory findings of 865 varicella patients admitted to Beijing You'an Hospital, China, between January 2011 and December 2013 were collected and analyzed. Patients with isolated complication were grouped as SI (skin infection, n = 132) and LD (liver damage, n = 89). Two hundred and one patients without complications were grouped as control (mild group). Levels of T-cell subtypes and eight serum cytokines and were also tested. Levels of IFNg and IL-6 were monitored prospectively in another 12 grouped patients. SI was complicated in 21.7% (188/865) of varicella cases, and LD was complicated in 16.8% (145/865). The rates of SI and LD in varicella patients increased rapidly in the past three years. No laboratory findings were associated with SI or LD (all p > 0.05). IL-6 and IFNg levels were correlated with amniotic membrane extract (AME) (p = 0.044 and p = 0.038). Their levels peaked at day 1 of admission, and then started to decline. The incidence of serious complications has become more common in recent years. IL-6 and IFNg may possibly be used as early serum markers for identifying patients at risk of developing complications such as skin infections in varicella.

Integrated pharmacokinetics and biodistribution of multiple flavonoid C-glycosides components in rat after oral administration of Abrus mollis extract and correlations with bio-effects

Ethnopharmacological relevanceAbrus mollis, a commonly used traditional Chinese medicine in China and other Asia countries, has been used clinically to prevent and treat hepatitis and alcoholic liver disease for decades. Materials and methodsA modified HPLC–MS method was developed for the determination of vicenin-2 (AM-I), isoschaftoside (AM-II), and schaftoside (AM-III) of AM extract (AME) in rat plasma and tissues (heart, liver, spleen, lungs, and kidneys). Following oral administration of AME to rat at a dose of 200mg/kg, the concentrations of AM-I, II and III in plasma and tissues were quantified. An integrated double peak pharmacokinetics model was used to fit the concentration–time curves. The effects of drug on the bile flow and toe swelling of rats induced by carrageenan were also studied. ResultsThe limit of quantitation of this modified HPLC–MS method decreased from 25 to 5ng/mL for plasma and from 100 to 10ng/g for tissue. These concentration–time curves show two successive maximum concentrations. The results of integrated double peak pharmacokinetics in this paper indicated that the three flavonoid C-glycosides may be absorbed by two sites of intestine in vivo. These results of bile flow and toe swelling showed a significant correlation between the pharmacokinetics and pharmacodynamics. ConclusionsThe novel integrated double peak pharmacokinetic approach to studying the holistic pharmacokinetic properties of traditional Chinese medicine has been successfully developed and validated using AM as a model drug. This study would be a useful guide for the holistic double peak pharmacokinetic study in consistence with the intrinsic theory and characteristics of traditional Chinese medicine.

Effects of amniotic membrane extract on primary human corneal epithelial and limbal cells.

To assess the effects of amniotic membrane extract (AMX) on cellular activity of primary human corneal epithelial (HCE) cells under mechanical and oxidative stress, and on human limbal cells under oxidative stress. Corneal mechanical stress was simulated with a linear scratch in confluent HCE cell plates, then incubated with 0.1% AMX for 48 and 72 h. Subjecting HCE cultures to 0.5 mmol/L tertiary-butylhydroperoxide for 1 h simulated an oxidative stress. 0.1% AMX-treated cultures were compared with controls at 24 and 48 h using cellular viability assay, along with 12-h AMX pretreatment and human limbal cell comparisons. Mechanical stress on HCE cultures revealed a statistically significant distance ratio at 48 and 72 h in favour of 0.1% AMX-treated cultures (P = 0.021 and 0.035, respectively). Oxidative stress did not reveal any significant difference in cellular viability of AMX-treated versus control cultures. Twelve hour AMX pre-treatment prior to oxidative stress revealed a significant difference after 24 h from oxidative injury (73.3% AMX vs. 66.0% control, P = 0.035), but not after 48 h. Human limbal cells demonstrated significantly improved oxidative viability compared with HCE cells, with (91.0% vs. 82.0% control, P = 0.017) and without 0.1% AMX pre-treatment (91.2% vs. 83.7% control, P = 0.019). HCE cells treated with AMX healed faster after mechanical insult, suggesting a potential benefit in acute corneal injuries. Under oxidative stress, human limbal cells, a more proliferative cell type, showed superior viability compared with HCE cells.

Effect of Amniotic Membrane Extract on Cultured Human Nasal Mucosa Fibroblasts

Purpose: To investigate the effects of amniotic membrane extract (AME) on the survival of cultured human nasal mucosa fibroblasts. Methods: Primary cultured human nasal mucosa fibroblasts were exposed to 0, 10, 20, or 30 μg/mL AME for 3 days. The survival of the human nasal mucosa fibroblasts was measured using the MTT assay and apoptosis was evaluated with flow cytometry using annexin-V/propidium iodide double staining. Results: AME decreased significantly in fibroblast proliferation after exposure to 10 μg/mL (p = 0.000), and caused significant apoptosis of the fibroblasts after exposure to 10 μg/mL (p = 0.024). Conclusions: AME decreased fibroblast proliferation in vitro at least through induction of apoptosis. Therefore, adjuvant use of AME during endonasal dacryocystorhinostomy may improve clinical outcomes. J Korean Ophthalmol Soc 2015;56(12):1939-1944

A new 2-oxy-N,N-dioctylacetamide grafted resin for the separation of trivalent actinides from nitric acid medium

Abstract A novel 2-oxy-N,N-dioctylacetamide anchored on Merrifield resin was synthesized and characterized by elemental analysis, TG-DTA and IR spectroscopy, for the first time. The extraction behavior of Am(III) and Eu(III) from nitric acid medium in the dioctylacetamide anchored resin (R-DOA) was studied as a function of various parameters such as duration of equilibration, concentration of nitric acid and sodium nitrate etc. The distribution coefficient (K d) of Am(III) and Eu(III) in R-DOA increased with increase in concentration of nitric acid. The K d values reached a maximum at 3–4 M nitric acid concentration in both cases, followed by decrease in K d values. Rapid extraction of Am(III) and Eu(III) from nitric acid medium was observed in the initial stages of equilibration followed by the establishment of equilibrium occurred within 60 min. The extraction data was fitted in to the first order rate equation. The recovery of Am(III) and Eu(III) from the loaded organic phase was studied using dilute nitric acid. The results revealed that 2-oxyacetamide functionalized resin is the promising candidate for the separation of trivalent actinides and lanthanides from nitric acid medium.

A Novel Solvent System Involving Terpyridine and Cyanex-301 for Am(III) and Eu(III) Separation from Weakly Acidic Feeds

Separation of trivalent actinides and lanthanides is a challenging task and has a great relevance in the nuclear fuel cycle. Bis(2,4,4-trimethylpentyl)dithiophosphinic acid (Cyanex-301) show high selectivity for the trivalent actinides over the lanthanides at pH 3 or higher and N-donor ligands were reported to enhance the selectivity. 2,2ʹ:6ʹ,6”-Terpyridine (terpy), on the other hand, has shown to be quite effective at lower pH values and the combination of Cyanex 301 and terpy was evaluated in the present study, for the first time, for the separation of Am(III) from Eu(III), representative actinide and lanthanide elements, respectively at pH 2.0.Thermodynamic parameters (enthalpy, entropy, and free energy) for the two phase extraction were also determined from the distribution studies at variable temperatures. Extraction of both Am3+ and Eu3+ was favored by negative enthalpy of extraction. More negative ΔG value indicated that Am3+ extraction was more favoured as compared to Eu3+ extraction using this solvent system. Effect of diluent composition on the extraction of Am3+ and Eu3+ was also studied in the present work.

Studies on the feasibility of using completely incinerable reagents for the single-cycle separation of americium(III) from simulated high-level liquid waste

Abstract The extraction and stripping behavior of various metal ions present in the fast reactor simulated high-level liquid waste (FR-SHLLW) was studied using a solvent phase composed of a neutral extractant, N,N,-didodecyl-N′,N′-dioctyl-3-oxapentane-1,5-diamide (D3DODGA) and an acidic extractant, di-2-ethylhexyl diglycolamic acid (HDEHDGA) in n-dodecane (n-DD). The third phase formation behavior of the solvent formulation D3DODGA + HDEHDGA/n-DD, was studied when it was contacted with FR-SHLLW, and the concentration of neutral and acidic extractant needed to avoid the third phase formation was optimized. The distribution ratio of various metal ions present in FR-SHLLW was measured in a solution of 0.1 M D3DODGA + 0.2 M HDEHDGA/n-DD. The extraction of Am(III) was accompanied by the co-extraction of lanthanides and unwanted metal ions such as Zr(IV), Y(III), and Pd(II). A procedure was developed to minimize the extraction of unwanted metal ions by using aqueous soluble complexing agents in FR-SHLLW. Based on those results, the counter-current mixer-settler run was performed in a 20-stage mixer-settler. Quantitative extraction of Am(III), Ln(III), Y(III), and Sr(II) in 0.1 M D3DODGA + 0.2 M HDEHDGA/n-DD was observed. The recovery of Am(III) from the loaded organic phase was carried out by the optimized aqueous formulation composed of 0.01 M diethylenetriaminepentaacetic acid (DTPA) + 0.5 M citric acid (CA) at pH 1.5. The stripping of Am(III) was accompanied by co-stripping of some early lanthanides. However the later lanthanides (Eu(III) and beyond) were not back extracted to Am(III) product. Therefore, the studies foresee the possibility of intra-lanthanides as well as lanthanide-actinide separation in a single-processing cycle.

Insights Into the Extraction of Am(III) by Aliquat-336 Based Ionic Liquids

The extraction behavior of Am(III) in a solution of tetra-(2-ethylhexyl)diglycolamide (TEHDGA) in n−dodecane (n−DD) or toluene was studied as a function of nitric acid concentration. The distribution ratio of Am(III) in 0.1 M TEHDGA/molecular diluent increased with increase in the concentration of nitric acid. Since the Aliquat-336 based ionic liquid namely, tri-n-octylmethylammonium di-(2-ethylhexyl)phosphate ([A336]+[DEHP]−) was miscible in molecular diluents such as n-DD and toluene, the extraction behavior of Am(III) in TEHDGA/molecular diluent was investigated in the presence of small concentrations of ionic liquid to understand the role of ionic liquid in extraction. The distribution ratio of Am(III) in 0.2 M [A336]+[DEHP]−/molecular diluent was negligible. Significant increase in distribution ratio of Am(III) was observed when [A336]+[DEHP]− was added to 0.1 M TEHDGA/molecular diluent. Since [A336]+[DEHP]− was converted into its components, namely tri-n-octylmethylammonium nitrate ([A336]+[NO3]−) and di-(2-ethylhexyl)phosphoric acid (HDEHP) when contacted with nitric acid, the extraction behavior of Am(III) in 0.1 M TEHDGA/molecular diluents was also studied in the presence of [A336]+[NO3]− and HDEHP to elucidate the mechanism of extraction. The study confirmed that the extraction of Am(III) in ionic liquid medium was controlled by constituents of ionic liquid and the distribution ratio of Am(III) obtained in organic phase was due to the resultant of contributions of ionic liquid constituents.

Synthesis and Screening of t-Bu-CyMe4-BTBP, and Comparison with CyMe4-BTBP

The effect of adding a t-butyl group to the core molecule of CyMe4-BTBP, with the aim of improving solubility in organic diluents, has been studied with regard to the extraction of Am(III) and Eu(III) from HNO3. Synthesis of t-Bu-CyMe4-BTBP is described in detail. Metal nitrates are extracted from nitric acid in the form of 1:2 complexes, M(NO3)3(BTBP)2. Whether in 1-octanol, kerosene, or cyclohexanone diluents, t-Bu-CyMe4-BTBP extracts with larger distribution ratios but with slower kinetics than CyMe4-BTBP. The general trends previously observed for CyMe4-BTBP regarding the diluent and modifier influence were also found for t-Bu-CyMe4-BTBP.

Extraction Behavior of Am(III) and Eu(III) from Nitric Acid Medium in Tetraoctyldiglycolamide-Bis(2-Ethylhexyl)Phosphoric Acid Solution

The extraction behavior of Am(III) and Eu(III) in a solution of tetra-octyldiglycolamide (TODGA), bis(2-ethylhexyl)phosphoric acid (HDEHP), and n-dodecane (n-DD) was studied to understand the role of TODGA and HDEHP in the combined solvent system. The extraction behavior of these metal ions was compared with those observed in TODGA/n-DD and HDEHP/n-DD. The effect of various parameters such as concentrations of HNO3, TODGA, and HDEHP on the distribution ratio of Am(III) and Eu(III) was studied. Synergistic extraction of both the metal ions observed at lower acidities (<2.0 M) was attributed to the involvement of TODGA and HDEHP for extraction. However, the extraction of Am(III) and Eu(III) in the combined solvent was comparable with that observed in TODGA at higher acidities. The slope analysis of the extraction data confirmed the involvement of both the extractants at all acidities investigated in the present study.

Feasibility of Using Di-Dodecyl-Di-Octyl Diglycolamide for Partitioning of Minor Actinides from Fast Reactor High-Level Liquid Waste

The unsymmetrical diglycolamide, di-dodecyl-di-octyl diglycolamide (D3DODGA) is a modifier-free extractant proposed for partitioning of trivalent actinides from nitric acid medium. D3DODGA has been evaluated for the feasibility of using it in the absence of a phase modifier, for the partitioning of minor actinides from fast reactor high-level liquid waste (FR-HLLW). The extraction behavior of various metal ions present in the simulated FR-HLLW was studied in a solution of 0.1 M D3DODGA/n-dodecane from nitric acid medium. The distribution ratio of about 20 metal ions was measured as a function of concentration of nitric acid and other interfering ion. The extraction was found to be strongly dependent on the oxidation state of the metal ion. The extraction of Am(III) from 3–4 M nitric acid medium was quantitative in a single contact. However, it was accompanied by the quantitative extraction of fission products such as trivalent lanthanides (Ln(III)), Y(III), and Zr(IV). The extraction of Sr(II), Pd(II), and Ru(III) in 0.1 M D3DODGA/n-dodecane was not insignificant, but quite low. The extraction of Ba(II), Ni(II), Mo(VI), and Fe(III) was marginal and the extraction of Co(II), Sb(III), Mn(II), and Cs(I) in 0.1 M D3DODGA/n-dodecane was negligible. Our results indicated that 0.1 M D3DODGA/n-dodecane is a promising candidate for the separation of trivalent actinides from fast reactor high-level liquid waste containing significant quantities of trivalent lanthanides and actinides.

Solvent extraction studies of plutonium(IV) and americium(III) in room temperature ionic liquid (RTIL) by di-2-ethyl hexyl phosphoric acid (HDEHP) as extractant

Solvent extraction of Pu(IV) and Am(III) from aqueous nitric acid into room temperature ionic liquid (RTIL) by an acidic extractant HDEHP (di-2-ethyl hexyl phosphoric acid) was carried out. The D values indicated substantial extraction for Pu(IV) and poor extraction for Am(III) at 1M aqueous nitric acid concentration. However at lower aqueous nitric acid concentrations (pH 3), the Am(III) extraction was found to be quantitative. The least squares analysis of the extraction data for both the actinides ascertained the stoichiometry of the extracted species in the RTIL phase for Pu(IV) and Am(III) as [PuH(DEHP)2]3+, AmH(DEHP)2+. From the D values at two temperatures, the thermodynamic parameters of the extraction reaction for Pu(IV) was calculated.

Solvent systems containing diglycolamide-functionalised calix[4]arenes in room temperature ionic liquid for metal ion extraction: studies with simulated high-level wastes

The extraction of actinide ions such as Am(III), Pu(IV), Np(IV), U(VI) and Pu(VI) was studied from simulated high-level waste (SHLW) solutions using several diglycolamide-functionalised calix[4]arene (Calix-DGA) ligands dissolved in the room temperature ionic liquid (RTIL) [C8mim][NTf2]. The Calix-DGA ligands were three lower-rim functionalised ligands with varying alkyl substituents (L-I, L-II and L-III), an upper-rim functionalised ligand (L-IV) and an upper- and lower-rim functionalised ligand (L-V). The SHLW solutions used contained 0.5 M HNO3 and the extraction trend of the actinides was found out to be Am(III) > Pu(IV)∼Np(IV)≫ and the extraction efficiency of the Calix-DGA ligands for Am(III) being L-V>L-I>L-II>L-IV>L-III. Reasonably, good extraction of Am(III) was obtained with 5.0 × 10− 4 M ligand solutions suggesting that higher concentrations of the ligand can be used for a higher loading of the metal ions. The extraction of other metal ions representing fission products, structural materials and process chemicals was studied by Inductively Coupled Plasma –Atomic Emission Spectroscopy analysis. The extraction mechanism follows the cation-exchange mechanism often observed with RTIL-based extraction systems. Enthalpy changes were measured from van't Hoff plots and were found to be significantly different than those observed with tracer studies reported previously.

Single-cycle method for partitioning of trivalent actinides using completely incinerable reagents from nitric acid medium

Abstract A new approach, namely “Single-cycle method for partitioning of Minor Actinides using completely incinerable ReagenTs” (SMART), has been explored for the separation of Am(III) from Eu(III) present in nitric acid medium. The extraction behavior of Am(III) and Eu(III) in a solution of an unsymmetrical diglycolamide, N,N,-didodecyl-N′,N′-dioctyl-3-oxapentane-1,5-diamide (D3DODGA), and an acidic extractant, N, N-di-2-ethylhexyl diglycolamic acid (HDEHDGA), in n-dodecane was studied. The distribution ratio of both these metal ions in D3DODGA-HDEHDGA/n-dodecane initially decreased with increase in the concentration of nitric acid reached a minimum at 0.1 M nitric acid followed by increase. Synergic extraction of Am(III) and Eu(III) was observed at nitric acid concentrations above 0.1 M and antagonism at lower acidities. Contrasting behavior observed at different acidities was probed by the slope analysis of the extraction data. The study revealed the involvement of both D3DODGA and HDEHDGA during synergism and increased participation of HDEHDGA during antagonism. The stripping behavior of Am(III) and Eu(III) from the loaded organic phase was studied as a function of nitric acid, DTPA, and citric acid concentrations. The conditions needed for the mutual separation of Am(III) and Eu(III) from the loaded organic phase were optimized. Our studies revealed the possibility of separating trivalent actinides from HLLW using these completely incinerable reagents.

Can leg ulcer fibroblasts phenotype be influenced by human amniotic membrane extract?

Prevalence of leg ulcer in general population is important and new efficient treatments are now needed, especially for chronic leg ulcers. Human amniotic membrane (HAM) can be used as an alternative treatment for recalcitrant leg ulcers. The aim of this study is to investigate the effects of a HAM extract on normal fibroblasts (NF) and ulcer fibroblasts (UF). NF and UF were obtained from biopsies by explants technique. HAM extract was used at 10 μg of total proteins per ml. Single patient-matched NF and UF were compared, without or with HAM extract. Studied parameters were proliferation rate, retraction of free-floating lattices, alpha smooth muscle actin expression by flow cytometry, and synthesis of elastin, glycosaminoglycans (GAGs), pro-collagen I, MMP-1 and TIMP-1. Our results show that UF had a specific phenotype compared to NF: low proliferation, high expression of alpha-SM actin and high synthesis of MMP-1, TIMP-1 and elastin. HAM extract significantly increased the synthesis of GAGs, pro-collagen I and MMP-1 in NF and decreased retraction of free lattices. HAM extract transiently increased UF proliferation, slowed down lattices retraction and decreased elastin synthesis. In conclusion, HAM extract has little effect on UF for the parameters studied and NF are more responsive than UF. However, clinical beneficial effect of HAM application on leg ulcers was previously observed and might rather be related to an action on keratinocytes and/or a modulation of the highly inflammatory environment of these chronic wounds.

Characterizing Diamylamylphosphonate (DAAP) as an Americium Ligand for Nuclear Fuel-Cycle Applications

Successful deployment of the currently-envisioned advanced nuclear fuel cycle requires the development of a partitioning scheme to separate Am from the lanthanides. The Am/lanthanide separation is challenging since all the metals are normally trivalent and have similar ionic radii. Oxidation of Am to higher oxidation states is one option to achieve such a separation. Hexavalent Am has now been routinely prepared in our laboratory in strongly acidic solution using sodium bismuthate as the oxidant, and then extracted into diamylamylphosphonate/dodecane solution. Here, we have characterized this phosphonate-containing solvent with regard to the extraction of Am, the lanthanides, Cm, other fission product, and/or inert constituents expected in dissolved nuclear fuel. Additionally, the effects of irradiation on dispersion numbers and the phosphonate concentration were investigated.

Amniotic Membrane Extract Preparation: What is the Best Method?

Purpose:To compare different preparation methods for a suitable amniotic membrane (AM) extract containing a given amount of growth factors.Methods:In this interventional case series, we dissected the AM from eight placentas within 24 hours after delivery, under clean conditions. After washing and mixing, AM extracts (AMEs) were prepared using pulverization and homogenization methods, and different processing and storing conditions. Main outcome measures were the amount of added protease inhibitor (PI), the relative centrifugal force (g), in-process temperature, repeated extraction times, drying percentage, repeated pulverization times, and the effect of filtering with 0.2 μm filters. Extract samples were preserved at different temperature and time parameters, and analyzed for hepatic growth factor (HGF) and total protein using ELISA and calorimetric methods, respectively.Results:The extracted HGF was 20% higher with pulverization as compared to homogenization, and increased by increasing the PI to 5.0 μl/g of dried AM. Repeating centrifugation up to 3 times almost doubled the extracted HGF and protein. Storing the AME at −170° for 6 months caused a 50% drop in the level of HGF and protein. Other studied parameters showed no significant effect on the extracted amount of HGF or total protein.Conclusion:Appropriate extraction methods with an adequate amount of PI increases the level of extractable components from harvested AMs. To achieve the maximal therapeutic effects of AMEs, it is necessary to consider the half-life of its bioactive components.

Evaluation of radiation stability of N,N-didodecyl N′,N′-di-octyl diglycolamide: a promising reagent for actinide partitioning

The radiation stability of N,N-di-dodecyl-N′,N′-di-octyl-3-oxapentane-1,5-diamide (D3DODGA) was studied by γ-irradiation of the solvent up to a absorbed dose of 1,000 kGy. The effect of γ-irradiation on the radiolytic degradation of D3DODGA was assessed by measuring the distribution ratio of Am(III) (DAm(III)) as well as the third phase formation in the irradiated D3DODGA-n-dodecane solution. The DAm(III) in the irradiated solution decreased with increase of absorbed dose. The critical aqueous concentration of Nd(III) above which the third phase forms, increased with increase of absorbed dose. However, the limiting organic concentration of Nd(III) remained at ~25 mM irrespective of the absorbed dose. Recovery of Am(III) from the radiolytically degraded organic phase showed that back extraction of Am(III) was quantitative in a few contacts using dilute nitric acid. Our studies clearly indicated that radiolytic degradation of D3DODGA in n-dodecane is marginal even at the absorbed dose of 1,000 kGy, and therefore D3DODGA is a potential candidate for minor actinide partitioning.