N-acetylcysteine and zinc sulphate abate di-2-ethylhexyl phthalate-mediated reproductive dysfunction in rats:Focus on oxidative and sex hormone receptors mechanisms

Objective:To investigate the potential of N-acetylcysteine(NAC)and zinc sulphate(ZnSO_(4))in mitigating reproductive dysfunction caused by di-2-ethylhexyl phthalate(DEHP)in rats and to understand the underlying mechanisms,specifically oxidative stress and sex hormone receptor activity.Methods:Thirty-five male Wistar rats were randomly divided into five equal groups(n=7 per group).Group 1 was administered 0.5 mL of distilled water and served as the control group.Group 2 was given only DEHP(750 mg/kg/day),while group 3,4 and 5 were given DEHP(750 mg/kg/day)plus NAC(100 mg/kg/day),DEHP(750 mg/kg/day)plus ZnSO_(4)(0.5 mg/kg/day),and DEHP(750 mg/kg/day)plus NAC(100 mg/kg/day)as well as ZnSO_(4)(0.5 mg/kg/day),respectively.All treatments lasted for 21 days.Samples were obtained after the rats were sacrificed,and hormones levels in the serum and markers of oxidative stress in the testicles were analyzed using the enzyme-linked immunosorbent assay.The amount of androgen receptors in the testicles was determined by immunohistochemistry,and the susceptibility of testosterone and DEHP to bind to androgen receptor and 5α-reductase was determined by molecular docking studies.Results:DEHP decreased reproductive hormones,testicular antioxidant enzymes,increased malondialdehyde levels,and negatively impacted histology of the pituitary and testes.NAC or ZnSO_(4) treatment showed a marked improvement in testicular antioxidant status and hormone levels,as well as a positive effect on the histology of the pituitary and testes.The combination of both treatments appeared to be more effective.The affinity of DEHP to bind to androgen receptors may lead to disruption of androgen receptor signaling,which can further result in dysfunction of hormones related to androgen.However,NAC is more likely to form stronger binding interactions with follicle stimulating hormone and luteinizing hormone receptors,as well as gonadotropin-releasing hormone receptors,when compared to DEHP.Conclusions:The possibility that NAC and ZnSO_(4) could downregulate DEHP-induced sex hormone changes is suggested by their potential to reduce toxicity.

二维聚合物[MnNa(Salicylate)_2(CH_3OH)(H_2O)]_n·0.5nH_2O的合成、晶体结构与活性研究

In this paper, a novel polymeric complex [MnNa（Salicylate）2（CH3OH）（H2O）]n·0.5nH2O was obtained and characterized by IR spectra, elemental analysis and single crystal X-ray diffraction. The titled complex is crystallized in triclinic system, space group P1 with a=0.763 82（15） nm, b= 1.037 1（2） nm, c=1.290 9（3） nm, α= 103.59（3）°, β=104.65（3）°, γ=109.50（3）°, V=0.873 6（3） nm 3, Z=2, Dc=1.556 Mg/m 3, Mr=409.20, μ=0.823 mm -1, F（000）=418, R=0.0614, wR= 0.147 6. The activity in catalyzing the superoxygen anionic free radical dismutation was determinated.

2%超分子水杨酸对UVB所致小鼠光老化损伤的修复研究

目的 探究2%超分子水杨酸对中波紫外线(UVB)所致小鼠光老化损伤的修复作用。方法 选择30只6~8周龄昆明雌鼠,随机分为空白对照组、UVB组、UVB+2%超分子水杨酸组,各10只。空白对照组小鼠正常日光照射饲养, UVB组、UVB+2%超分子水杨酸组隔日用UVB照射1次,辐照12周,其中UVB+2%超分子水杨酸组小鼠在UVB照射后涂抹1次2%超分子水杨酸,非照射日每日涂抹1次;最后1次辐照结束后48 h观察三组小鼠皮肤组织形态变化情况,应用苏木精-伊红(HE)染色观察小鼠背部皮肤显微结构改变情况,测定表皮、真皮厚度,应用Masson染色观察真皮胶原纤维排列情况,测定胶原纤维含量,用免疫组化染色观察皮肤组织p21、p53表达情况。比较三组小鼠背部皮肤外形情况、皮肤显微结构改变情况及皮肤组织p21、p53阳性表达情况。结果 与空白对照组相比,UVB组小鼠皮肤粗糙,有深皱纹毛孔扩大,缺乏弹性,皮肤呈褐黄色斑,皮革样外观,镜下见毛细血管扩张,结痂,为典型光老化特征;UVB+2%超分子水杨酸组皮肤外观有隐约褐色斑,镜下见皮肤有散在、不规则褐色斑片,光老化症状较轻。三组背部皮肤损伤程度比较有明显差异性(P<0.05);UVB组背部皮肤损伤程度明显大于空白对照组和UVB+2%超分子水杨酸组,有明显差异性(P<0.05);空白对照组与UVB+2%超分子水杨酸组皮损程度比较也有明显差异性(P<0.05)。空白对照组表皮厚度、真皮厚度、真皮胶原纤维含量分别为(18.55±1.80)μm、(350.08±35.16)μm、(0.46±0.05)OD, UVB组分别为(79.68±21.37)μm、(611.62±16.37)μm、(0.15±0.30)OD, UVB+2%超分子水杨酸组分别为(60.99±11.49)μm、(467.94±20.71)μm、(0.32±0.03)OD。三组表皮厚度、真皮厚度及真皮胶原纤维含量比较有明显差异性(P<0.05);UVB+2%超分子水杨酸组和UVB组表皮厚度、真皮厚度明显多于空白对照组,真皮胶原纤维含量显著少于空白对照组,有明显差异性(P<0.05);UVB+2%超分子水杨酸组表皮厚度、真皮厚度明显少于UVB组,真皮胶原纤维含量多于UVB组,有明显差异性(P<0.05)。免疫组化显示空白对照组未见有p21、p53阳性表达。UVB+2%超分子水杨酸组皮肤组织p21、p53阳性表达率分别为30.00%、10.00%,低于UVB组的80.00%、60.00%,有明显差异性(P<0.05)。结论 2%超分子水杨酸对UVB所致小鼠光老化皮肤有修护保护作用,其机制与抑制凋亡相关基因p21、p53表达有关。

30%超分子水杨酸联合小光斑点阵CO_(2)激光治疗轻中度寻常痤疮

目的:探究30%超分子水杨酸联合小光斑点阵CO_(2)激光治疗轻中度寻常痤疮的有效性和安全性。方法:选取2022年11月-2023年6月就诊于吉林大学中日联谊医院30例面部轻、中度寻常痤疮患者,以患者面部矢状线为界,按照随机数表将患者的双侧面部随机分为对照侧和观察侧。对照侧(n=30),给予30%超分子水杨酸治疗(每4周治疗1次);观察侧(n=30),给予小光斑点阵CO_(2)激光治疗后即刻30%超分子水杨酸治疗(每4周治疗1次)。通过拍照、皮肤检测仪、皮损计数和痤疮综合分级系统(The global acne grading system,GAGS)评分等评估治疗的有效性;通过皮损清除率判定临床疗效,同时观察不良反应以评估安全性。治疗结束后12周对患者进行随访,评估复发情况。结果:治疗12周后,患者观察侧的临床疗效优于对照侧(P<0.05);观察侧的皮损清除效果明显优于对照侧(P<0.001);观察侧的GAGS评分改善程度明显优于对照侧(P<0.001)。治疗期间两侧均未出现严重不良反应。结论:30%超分子水杨酸联合小光斑点阵CO_(2)激光疗法对清除轻中度痤疮皮损优于30%超分子水杨酸单一治疗,具有见效快、安全性高、操作简单、患者满意度高等优点,且不增加患者相关不良反应。

Intensified reactive extraction of 4-hydroxypyridine with di(2-ethylhexyl) phosphoric acid in 1-octanol by using tributyl phosphate

The efficient separation of amphoteric organic compounds from dilute solutions is of great importance in the industrial field. In the present work, the reactive extractions of 4-hydroxypyridine(4-HP) with tributyl phosphate(TBP), di(2-ethylhexyl) phosphoric acid(D2EHPA) and TBP + D2EHPA dissolved in 1-octanol were investigated, respectively. The influences of the initial concentrations of TBP, D2EHPA and TBP + D2EHPA on distribution ratio(D) were discussed, as well as the reactive extraction mechanism were proposed. The obvious intensification effect was observed when the mixture of TBP and D2EHPA was used as extractant. The best extraction conditions were found to be of the molar ratio of D2EHPA and TBP at 2:1 and the equilibrium aqueous pH at 3.50-4.50. D values increased with the increase of the total concentration of TBP and D2EHPA in 1-octanol. Especially, the analysis on the extraction mechanisms clearly indicate(i) TBP in 1-octanol shows negligible reactive extraction toward 4-HP,(ii) D2EHPA in 1-octanol exhibits moderate extraction effect by forming 4-HP:D2EHPA(1:1) and 4-HP:2D2EHPA(1:2) type complexes, while(iii) D2EHPA in TBP/1-octanol demonstrates the maximum distribution ratio with the 4-HP:D2EHPA(1:1) type complex domination. The discussion provides new insights on the mechanism and opens a new way for the intensified extraction of amphoteric organic compounds by using the mixture of multiple extractants in the diluent.

Green tea polyphenols alleviate di-(2-ethylhexyl)phthalate-induced liver injury in mice

BACKGROUND Di(2-ethylhexyl)phthalate(DEHP)is a common plasticizer known to cause liver injury.Green tea is reported to exert therapeutic effects on heavy metal exposureinduced organ damage.However,limited studies have examined the therapeutic effects of green tea polyphenols(GTPs)on DEHP-induced liver damage.AIM To evaluate the molecular mechanism underlying the therapeutic effects of GTPs on DEHP-induced liver damage.METHODS C57BL/6J mice were divided into the following five groups:Control,model[DEHP(1500 mg/kg bodyweight)],treatment[DEHP(1500 mg/kg bodyweight)+GTP(70 mg/kg bodyweight),oil,and GTP(70 mg/kg bodyweight)]groups.After 8 wk,the liver function,blood lipid profile,and liver histopathology were examined.Differentially expressed micro RNAs(miRNAs)and mRNAs in the liver tissues were examined using high-throughput sequencing.Additionally,functional enrichment analysis and immune infiltration prediction were performed.The miRNA-mRNA regulatory axis was elucidated using the starBase database.Protein expression was evaluated using immunohistochemistry.RESULTS GTPs alleviated DHEP-induced liver dysfunction,blood lipid dysregulation,fatty liver disease,liver fibrosis,and mitochondrial and endoplasmic reticulum lesions in mice.The infiltration of macrophages,mast cells,and natural killer cells varied between the model and treatment groups.mmu-miR-141-3p(a differentially expressed miRNA),Zcchc24(a differentially expressed mRNA),and Zcchc24(a differentially expressed protein)constituted the miRNA-mRNA-protein regulatory axis involved in mediating the therapeutic effects of GTPs on DEHP-induced liver damage in mice.CONCLUSION This study demonstrated that GTPs mitigate DEHP-induced liver dysfunction,blood lipid dysregulation,fatty liver disease,and partial liver fibrosis,and regulate immune cell infiltration.Additionally,an important miRNAmRNA-protein molecular regulatory axis involved in mediating the therapeutic effects of GTPs on DEHP-induced liver damage was elucidated.

A Meta-analysis of Salicylates for Type 2 Diabetes Mellitus

The aim of this study was to assess the effects and safety of salicylates on type 2 diabetes mellitus （T2DM）. We searched six databases （Cochrane Central Register of Controlled Trials, MED- LINE, EMBASE, CBM, CNKI and VIP） for all randomized controlled trials （RCTs） and self-control studies which investigated the effects of salicylates on T2DM. We included 34 RCTs and 17 self-control studies involving 13 464 patients with T2DM. It was demonstrated that salicylates had obvious effects on several parameters for patients with T2DM. （1） Any dose of salicylates could significantly reduce HbAIc level [mean difference （MD） -0.39%; 95% C1-0.47 to -0.32] in RCTs, but only high doses of salicylates （〉3000 mg/day） could effectively reduce fasting plasma glucose （FPG） level [standardized mean difference （SMD） -1.05; 95% CI -1.47 to -0.62] for patients with T2DM in both RCTs and self-control studies. Furthermore, high doses of salicylates could also increase plasma fasting insulin level （MD 12.20 mU/L; 95% CI 3.33 to 21.07）; （2） In both RCTs and self-control studies, high doses of salicylates could significantly reduce plasma triglycerides concentration. The results for RCTs were MD -0.44 mmol/L, 95% CI -0.71 to 4）.18, and those for self-control studies were 227±29 mg/dL （pre-treatment） and 117±8 mg/dL （post-treatment） （P=-0.009）; （3） All trials which reported cardiovascu- lar events were RCTs using low doses （〈1000 mg/day） of salicylates, and it was revealed that aspirin could significantly reduce the risk of myocardial infarction （OR 0.73; 95% CI 0.57 to 0.92）; （4） Two RCTs and two self-control studies with 〉3000 mg/day salicylates reported adverse effects, and the over- all effects were mild, and tinnitus occurred most frequently. No evidence of gastrointestinal bleeding was found in all these studies. In conclusion, from our systematic review, the anti-diabetic effect of salicylates is in a dose-dependent manner. High doses of salicylates may have beneficial effects on re- ducing FPG, HbAlc level and increasing fasting insulin concentration, and may also have some positive effects on lipidemia and inflammation-associated parameters for patients with T2DM, without serious adverse effects.

Catalytic Synthesis of Salicylate Esters over Cordierite Honeycomb Coated with Mo (VI)/ZrO₂

Solid acids such as ZrO2 & Mo (VI)/ZrO2 were coated on a honeycomb monolith by impregnation method. These catalytic materials were characterized by NH3-TPD, PXRD and SEM techniques. Salicylate esters were synthesized via transesterification of methyl salicylate with different alcohols over these catalytic materials. An excellent yield of Salicylate esters was obtained under specific reaction conditions. A correlation between the surface acidity, PXRD phase and catalytic activity of Mo (VI)/ZrO2 was observed. The thermally regenerated catalytic material was reused repeatedly with a consistent high yield of salicylate esters. The honeycomb coated with zirconia catalysts were found to be economical, efficient and ecofriendly (3E concept).

Participation of H_2O_2 in Enhancement of Cold Chilling by Salicylic Acid in Banana Seedlings

The possible physiological mechanism of enhancement of cold tolerance by salicylic acid (SA) in banana seedlings ( Musa acuminata cv. Williams 8188) was explored. Measurements of leakage electrolyte after 2 d of recovery at 30/22 ℃ (day/night) following 3 d of cold stress at 7 ℃ showed that pretreatment with hydroponic solution containing SA 0.3-0.9 mmol/L as foliar spray under normal growth conditions (30/22 ℃) could significantly enhance cold tolerance of banana plants. The highest enhancing effect of SA occurred at 0.5 mmol/L and it showed the lowest leakage rate of electrolyte or smaller leaf wilting area after 2 d of recovery at normal temperature from 3 d of 7 ℃ or 5 ℃ cold stress. Higher concentrations (≥2.5 mmol/L) of SA, however, caused more electrolyte leakage, indicating that they aggravated chilling damage. Enhanced cold tolerance by SA could be related to H 2O 2 metabolism. Compared with water_treated seedlings (control), SA 0.5 mmol/L treatment inhibited activities of catalase (CAT) and ascorbate peroxidase (APX), increased peroxidase (POX) activity, but did not affect the activity of superoxide dismutase (SOD) under normal growth conditions, and these changes might lead to an accumulation of H 2O 2, whereas SA pretreatment enhanced the activities of CAT and APX, and reduced the increase in productions of H 2O 2 and thiobarbituric acid_reaction substances (TBARS) during subsequent 7 ℃ cold stress and recovery periods. Exogenous H 2O 2 treatments (1.5 -2.5 mmol/L) also increased cold tolerance of banana seedlings. Furthermore, pretreatment of banana seedlings with dimethylthiourea (a trap for H 2O 2) significantly inhibited cold tolerance induced by SA. These results suggested that endogenous H 2O 2 may be required for SA_enhanced cold tolerance. The significance of the interaction of SA, H 2O 2 and H 2O 2_metabolizing enzymes during cold stress has been discussed.

Comparison of the Effects of H_2O_2 and Salicylic Acid on Alternative Respiratory Pathway in Aged Potato Tuber Slices

The influences of exogenous H 2O 2 and salicylic acid (SA) treatments on the alternative respiratory pathway (ARP) in aged potato (Solanum tuberosum L.) tuber slices were compared. The results showed that both H 2O 2(5.0 mmol/L) and SA (0.1 mmol/L) treatments had a significant inducing effect on ARP capacity (V alt ) and its ratio to total respiration (V alt /V t) in potato slices aged for 24 h. With a monoclonal antibody against the alternative oxidase (AOX), Western blotting results showed that both H 2O 2 and SA treatments increased the AOX expression levels in aged potato tuber slices. However, the results of oxygen isotope discrimination experiments showed that H 2O 2 had no influence on the in vivo ARP activity (ρV alt ) and its contribution to V t(expressed as ρV alt /V t) in potato slices aged for 24 h, but SA had a significant influence on the ρV alt and ρV alt /V t values of the aged potato tuber slices. These results indicate that there are differences between the effects of H 2O 2 and SA on ARP in plant tissues. Both of them possess the ability to induce ARP capacity through inducing AOX expression. However, SA can simultaneously stimulate the operation of ARP, but H 2O 2 can not.

外源水杨酸对Na_(2)CO_(3)胁迫下矮牵牛幼苗生长的影响

为明确外源水杨酸(SA)对植物碱胁迫是否具有缓解作用,本试验以‘梦幻’系列矮牵牛为材料,研究叶面喷施0.75 mmol·L^(-1)SA对100 mmol·L^(-1)Na_(2)CO_(3)胁迫下幼苗生长、保护酶活性及叶绿素荧光参数的影响。结果表明,与对照(蒸馏水)相比,Na_(2)CO_(3)胁迫下矮牵牛幼苗株高、叶片数、植株鲜重和干重、总根长、总根表面积、根体积、细根(直径0~2 mm)根长及其表面积显著下降,POD、CAT活性显著升高,TRo/RC及PIabs显著下降。Na_(2)CO_(3)胁迫下与不喷施SA相比,叶面喷施SA提高矮牵牛幼苗株高、叶片数、地上部鲜重和干重、总根长、总根表面积、细根根长及其表面积,以及POD活性、ABS/RC、TRo/RC和PIabs。综合分析看出,Na_(2)CO_(3)胁迫显著抑制矮牵牛幼苗生长,叶面喷施SA可通过促进细根生长、提高保护酶活性及PSⅡ的光合性能,在一定程度上缓解Na_(2)CO_(3)胁迫对矮牵牛幼苗生长产生的抑制作用。

Effects of exogenous salicylic acid on growth and H_2O_2-metabolizing enzymes in rice seedlings under lead stress

Salicylic acid （SA） was an essential component of the plant resistance to pathogens and also plays an important role in mediating plant response to some abiotic stress. The possible effects of SA on the growth and H2O2-metabolizing enzymes in rice seedlings under lead stress were studied. When rice seedlings grown in nutrient solution containing Pb^2＋ （0, 0.05, 0.15, 0.25 mmol/L） for 18 d, the plant biomass as well as the chlorophyll content of leaves decreased with increasing Pb concentration. The pre-treatment with SA （treated with 0.1 mmol/L SA for 48 h before Pb stress） partially protected seedlings from Pb toxicity. The chlorophyll contents were significant higher in leaves of Pb-exposed with SA pre-treatment seedlings than in Pb-exposed plants at the same Pb intensity. SA pre-treated alone could significantly increase the length of shoot and root of seedlings but the vigour difference was not marked under long-term exposure to Pb toxicity. SA pre-treated influence the H2O2 level in leaves of seedlings by up-regulating the activity of superoxide dismutase （SOD）, repressing the activity of catalase （CAT） and ascorbate peroxidase （APX） depending on the concentrations of Pb^2＋ in the growth medium. The results supported the conclusion that SA played a positive role in rice seedlings against Pb toxicity.

Synergistic extraction of rare earth by mixtures of 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester and di-(2-ethylhexyl) phosphoric acid from sulfuric acid medium

The extraction of Nd^3＋ and Sm^3＋, including the extraction and stripping capability as well as the separation effect of Nd^3＋ or Sm^3＋, from a sulfuric acid medium, by mixtures of di-（2-ethylhexyl） phosphoric acid （HDEHP, H2A2（0）） and 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester （HEH/EHP, H2L2（0）） were studied. The distribution ratios and synergistic coefficients of Nd^3＋ and Sm^3＋ in different acidities were also determined. A synergistic extractive effect was found when HDEHP and HEH/EHP were used as mixed extractants for Sm^3＋ or Nd^3＋. The chemical compositions of the extracted complex were determined as Nd.（HA2）2-HL2 and Sm.（HA2）2-HL2. The extraction equilibrium constants, enthalpy change, and entropy change of the extraction reaction were also determined.

Glycerin Monostearate Aggravates Male Reproductive Toxicity Caused by Di(2-ethylhexyl)Phthalate in Rats

Human beings are increasingly exposed to phthalates,which are a group of chemicals used to make plastics more flexible and harder to break,and simultaneously ingesting abundant food emulsifiers via daily diet.The purpose of this study was to investigate the effect of the food emulsifier glycerin monostearate(GMS)on male reproductive toxicity caused by di(2-ethylhexyl)phthalate(DEHP,one of the phthalates)and explore the underlying mechanism.Thirty male Sprague-Dawley rats were randomly divided into control group,DEHP group and DEHP+GMS group.Rats in the DEHP group and DEHP+GMS group were orally administered with 200 mg/kg/d DEHP with or without 20 mg/kg/d GMS.After 30 days of continuous intervention,it was found that the serum testosterone level was significantly lowered in DEHP group and DEHP+GMS group than that in control group(P<0.01).The serum testosterone level and the relative testis weight were significantly decreased in the DEHP+GMS group as compared with those in the DEHP group and control group(P<0.05).More spermatids were observed to be shed off in DEHP+GMS group than in DEHP group.The expression levels of cell cycle checkpoint kinase 1(Chkl),cell division cycle gene 2(Cdc2),and cyclin-dependent kinase 2(CDK2)were down-regulated in DEHP group,and this tendency was more significant in DEHP+GMS group(P<0.05 or P<0.01).There was no significant difference in the P-glycoprotein(P-gp)expression between DEHP group and control group.However,P-gp was markedly down-regulated in DEHP+GMS group(P<O.Ol).The results indicated that the food emulsifier GMS aggravated the toxicity of DEHP on male reproduction by inhibiting the cell cycle of testicular cells and the expression of P-gp in testis tissues.

Reactive extraction for intensifying 2-ethylhexyl acrylate synthesis using deep eutectic solvent [Im:2PTSA]

2-Ethylhexyl acrylate(2-EHA)is one of the most widely used acrylates in the polymer industry,which is synthesized via Fisher esterification that is limited by chemical equilibrium.To intensify the esterification process,in this work,reactive extraction concept is proposed,with halogen-free deep eutectic solvent(DES[Im:2PTSA])as dual solvent-catalyst that consists of imidazole(Im)and p-toluenesulfonamide(PTSA).The bifunctional effects of the DES[Im:2PTSA]are evaluated by thermodynamic analysis and experimental study.Favorable phase splitting is verified byσ-potential analysis predicted by COSMO-RS theory,combined with experiments,and the optimal acid-to-alcohol molar ratio is set to 1.2.The esterification kinetics is then experimentally determined and fitted using the molar-based and activity-based pseudo-homogeneous(PH)models,respectively.The activity-based PH model,that considers the bifunctional roles of the DES,proves to be more accurate with small RMSD of 0.0344.The stability of DES after recycling is validated to further confirm the industrial prospects of DES[Im:2PTSA]in 2-EHA production.

Synergistic extraction of praseodymium with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester and 8-Hydroxyquinoline

The synergistic extraction of Pr^3＋ from hydrochloric medium using mixture of 2-ethylhexyl phosphonic acid mono- 2-ethylhexyl ester （P507, HL） and 8-Hydroxyquinoline （HQ） in heptane was investigated. The effect of equilibrium of aqueous acidity on extraction of Pr^3＋ was discussed. The effect of extractant concentraction, different diluents, equilibrium time and acetate ion concentration oil extraction reaction were also studied. With a method of double-logarithmic slope, composition of the extracted species on 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester and 8-Hydroxyquinoline was derived. The result shows that the synergistic extraction system not only overcomes emulsification of 8-Hydroxyquinoline, but also shows perfect capacity of synergistic extraction. The largest synergistic enhancement factor can be calculated to be 5.49 at pH 3.6 for Pr^3＋.

Solvent extraction equilibrium of dysprosium(Ⅲ) from nitric acid solutions with 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester

In view of the importance of solvent extraction of rare earth metals with the acidic organophosphorous reagent,the development of a chemically based model applicable to high concentration is desired.In the present study,the equilibrium distribution of dysprosium(Ⅲ)between an aqueous nitric acid solution and 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (PC88A)was measured in the range of an initial aqueous dysprosium(Ⅲ)concentration from 1.0×10-3to 1.0×10-1kmol/m 3and PC88A concentration from 0.16 to 0.65 kmol/m3in Shellsol D70 as the diluent.The obtained data were analyzed using the chemically based model in order to correlate the equilibrium distribution ratios.In this model,dysprosium(Ⅲ)was assumed to be extracted with the PC88A dimer as a 1:3 complex,the activities were considered for the aqueous species,and the effective concentration of the PC88A dimer was calculated using Alstad's empirical equation.As a result,the apparent extraction equilibrium constant was determined to be 253(kmol·m- 3)-2with an excellent correlation between the experiment and calculation results in the wide range of the logarithm of the distribution ratio from-2 to 3.5.In conclusion,the methodology in this model would be effective for quantitative description of solvent extraction behavior of general rare earth elements as well as dysprosium.

Synthesis of Highly-Selective Fibrous Adsorbent by Introducing 2-Ethylhexyl Hydrogen-2-Ethylhexylphosphonate for Scandium Adsorption

2-ethylhexyl hydrogen-2-ethylhexylphosphonate (EHEP) is commonly used as a metal extractant because it has a particular affinity for rare-earth metals like Scandium (Sc). To develop a highly-selective adsorbent of Sc(III), EHEP was introduced as a functional group onto a polyethylene fabric with radiation-induced graft polymerization(RIGP). The adsorption performances for Sc(III) were evaluated with aqueous solutions containing Sc(III) and Fe(III) in bath and column tests. As a result of column test, the adsorption capacities of Sc(III) and Fe(III) until the bed volume reached 5000 were 5.22 and 0.12 mg/g, respectively. It means that the amount of collected Sc(III) by the EHEP adsorbent was approximately 44 times higher than that of Fe(III). These results indicate that the grafted adsorbent containing EHEP has an extremely high selectivity for Sc(III) adsorption.

THE EXTRACTED COMPLEX FORMED BY MONO (2-ETHYLHEXYL)-2-ETHYLHEXYL PHOSPHATE WITH DIVALENT Mn

In order to clarify the mechanism and the complex formed in the extraction of divalent Mn by alkylphosphonic acid monoester, the solid complex has been prepared by mono (2-ethylhexyl)-2-ethylhexyl phosphate, HEH(EH)P, HA with divalent Mn. The elemental analysis, magnetic susceptibility and thermogravimetry have been determined for the solid complex of HEH(EH)P-Mn(II) and the infrared spectrum has been carried out in comparison to the extractant HEH(EH)P. The extracted compound has also been studied by electronic and electron spin resonance spectroscopy in octane solvent and solid state at room temperature. On the basis of the measurements, it is concluded that the structure of the solid polymeric species MnA_2 is in a tetrahedral arrangement.