A convenient synthesis of pyrroles catalyzed by acidic resin under solvent-free condition

A convenient and effective Paal-Knorr condensations of 2,5-hexanedione with most amines have been carried out at room temperature under solvent-free condition.Macroporous strongly acidic styrol resin(D001) as a novel,efficient,cost-effective,and reusable solid acid catalyst for the synthesis of pyrroles under the same conditions.The pyrroles were obtained in high yields in short reaction times.

Adsorption of Er(Ⅲ ) and Its Mechanism on Diglycolamidic Acid Resin

The adsorption behavior and mechanism of a novel chelate resin, diglycolamidic acid resin (DAAR) for Er(Ⅲ) were investigated. The optima adsorption condition of DAAR for Er(Ⅲ) is pH 6.20 in HAc NaAc medium. The statically saturated adsorption capacity is 189 mg·g -1 resin at 298 K. The Er (Ⅲ) adsorbed on DAAR can be eluted reaching 100% by 2 mol·L -1 HCl used as eluant. The resin can be regenerated and reused without apparent decreasing of adsorption capacity. The apparent adsorption rate constant is k 298 =1.94×10 -5 s -1 . The apparent activation energy is 24.7 kJ·mol -1 . The adsorption behavior of DAAR for Er(Ⅲ) obeys the Freundlich isotherm. The thermodynamic adsorption parameters, enthalpy change Δ H of DAAR for Er(Ⅲ) is 24.1 kJ·mol -1 . The molar coordination ratio of the functional group of DAAR to Er (Ⅲ) is 3∶1. The adsorption mechanism of DAAR for Er (Ⅲ) was examined by using chemical method and IR spectrometry. The coordination compound is formed between oxygen atoms in the functional group of DAAR and Er(Ⅲ).

Studies on Adsorption Behavior and Mechanism of Copper(Ⅱ) onto Amino Methylene Phosphonic Acid Resin

The adsorption behavior and the mechanism of a novel chelate resin, amino methylene phosphonic acid resin(APAR) for Cu(Ⅱ) were investigated. Cu(Ⅱ) was quantitatively adsorbed by APAR in the medium of pH=4 09. The statically saturated adsorption capacity is 181 mg/(g resin). Cu(Ⅱ) adsorbed on APAR can be eluted by 1 0-3 0 mol/L HCl. The rate constant is k 298 =5 58×10 -5 s -1 . The adsorption of Cu(Ⅱ) on APAR follows the Freundlich isotherm. The Δ H of the adsorption is 3 91 kJ/mol. The apparent activation energy is E a=21 4 kJ/mol. The coordination molar ratio of APAR to Cu(Ⅱ) is 1/1. It is shown that the nitrogen and the oxygen atoms in the functional group of APAR coordinate to Cu(Ⅱ).

Adsorption behavior and mechanism of D113 resin for lanthanum

The sorption properties of macroporous weak acid resin （D113） for La^3＋ ion were studied by chemical analysis and IR spectra. Experimental results indicate that the D113 resin has a good adsorption ability for La^3＋ at pH = 6.0 in the HAc-NaAc medium. The statically saturated adsorption capacity is 273.3 mg/g. Separation coefficients of βLa^3＋/Ce^3＋, βLa^3＋/Gd^3＋, βLa^3＋/Er^3＋, and βLa^3＋/Y^3＋ are 2.29, 3.64, 4.27, and 0.627, respectively. The apparent activation energy of adsorption, Ea is 18.4 kJ/mol, the thermodynamics parameters AH, AS, and AG of sorption are 4.53 kJ/mol, 61.8 J/（mol·K）, -13.9 kJ/mol, respectively. The adsorption behavior of D113 for La^3＋ obeys the Freundlich isotherm. La^3＋adsorbed on resin can be eluted by 2.0 mol/L HCl quantitatively.

Sorption Behavior and Mechanism of Indium(Ⅲ) onto Amino Methylene Phosphonic Acid Resin

The sorption behavior of amino methylene phosphonic acid resin (APAR) for In (Ⅲ ) was investigated . Experimental results show that In ( Ⅲ ) adsorbed on APAR can be elated with 2mol · L -1 HCl. The apparent rate constant is k29 = 1.50 × 10-5s-1. The sorption behavior of APAR for In ( Ⅲ ) obeys the Freundlich isotherm. The themodynamic parameters of sorption, enthalpy change ()H, free energy change ()G and entropy change ()S of sorption (APAR) for In ( Ⅲ ) are 24.1 kJ·mol-1, -35. 1kJ· mol-1 and 200J· mol-1·K-1 respectively. The coordination molar ratio of the functional group of APAR to In( Ⅲ ) is 2:1. The sorption mechanism of APAR for In( Ⅲ ) was examined by IR spectrometry.

Adsorption of Macroporous Phosphonic Acid Resin for Nickel

Tje adsorption bchavior and mechanism of a novel chelate resin,macroporous phosphonic acid resin（PAR）for Ni（Ⅱ）were imestigated.The stotically saturated adsorption capacity is 64.3mg·g^-1 resin at 298K in HAc-NaAc medium.The Ni（Ⅱ）adsorbed on PAR can be eluted by 0.5mal·L^-1 HCl and the elution percentage reaches 96.6%.The resin can be regenerated and reused without abvious decrease in adsorption capacity.The apparent adsorption rate constant is k298=2.6×10^-5s^-1.The adsorption behavior of PAR for Ni（Ⅱ）obeys the Freundllich isotherm.The thermodynamie adsorption parameters.enthalpy change △H,free energy change △G and entropy change △S of PAR for Ni（Ⅱ）are 3.36kJ·mol^-1,-5.47kJ·mol^-1 and 29.6J·mol^-1·K^-1,respectively.The apparent activation energy is Ea=12.2kJ·mol^-1,The molar coordination ratio of the functional group of PAR to Ni（Ⅱ）is about 4：1.The adsorption mechanism of PAR for Ni（Ⅱ）was examined by a chemical method and IR spectrometry.

Adsorption Behaviors and Mechanism of Macroporous PhosphonicAcid Resin for Gadolinium

The adsorption behaviors and mechanism of a novel chelate resin, macroporous phosphonic acid resin(PAR)for Gd(Ⅲ)were investigated. The statically and dynamically saturated adsorption capacity is respectively 308 mg·g^(-1)resin and 296 mg·g^(-1)resin at 298 K in HAc-NaAc medium at pH 5.6. Gd(Ⅲ)adsorbed on PAR can be reductively eluted by 0.5～5.0 mol·L^(-1) HCl used as eluant and the elution percentage is up to 94.7% in 1.0 mol·L^(-1) HCl. The resin can be regenerated and reused without apparent decrease in adsorption capacity. The apparent adsorption rate constant is k_(298)=3.96×10^(-5) s^(-1). The adsorption behavior of PAR for Gd(Ⅲ) conforms to the Freundlich isotherm. The thermodynamic adsorption parameter, enthalpy change △H of PAR for Gd(Ⅲ)is 22.6kJ·mol^(-1). The apparent adsorption activation energy(Ea)of PAR for Gd(Ⅲ)is 5.0 kJ·mol^(-1). The molar coordination ratio of the functional group of PAR to Gd(Ⅲ)is about 3∶1. The adsorption mechanism of PAR for Gd(Ⅲ)was examined by using chemical method and IR spectrometry.

Studies on the Adsorption of Amino Methylene Phosphonic Acid Resin for Holmium(Ⅲ)

The adsorption behavior and mechanism of a novel chelate resin, amino methylene phosphonic acid resin (APAR) for Ho(Ⅲ) were investigated. The statically saturated adsorption capacity is 258 mg·g^(-1) resin at 298 K in HAc-NaAc medium. The Ho(Ⅲ) adsorbed on APAR can be repeatedly eluted by 3.0 mol·L^(-1) HCl and the elution percentage is as high as 95.8%. The resin can be regenerated and reused without apparent decrease in adsorption capacity. The apparent adsorption rate constant is k_(298)=1.14×10^(-5) s^(-1). The adsorption behavior of APAR for Ho(Ⅲ) obeys the Freundlich isotherm. The thermodynamic adsorption parameter, enthalpy change ΔH of APAR for Ho(Ⅲ) is 11.4 kJ·mol^(-1). The apparent activation energy is E_a=15.8 kJ·mol^(-1). The molar coordination ratio of the functional group of APAR to Ho(Ⅲ) is about 2∶1. The adsorption mechanism of APAR for Ho(Ⅲ) was examined by using chemical method and IR spectrometry.

Sorption Behaviour and Mechanism of Lanthanum (Ⅲ) on HD-2 Resin

La(Ⅲ) was quantitatively adsorbed by macroporous weak acid resin (HD-2) in the medium of pH=6.16. The statically saturated sorption capacity is 231 mg·g -1(resin). 3.0 mol·L -1 HCl can be used as an eluant. The elution percentage is 100%. The sorption rate constant is k_ 298=3.04×10 -5 s -1. The apparent sorption activation energy of HD-2 for La(Ⅲ) is 31.2 kJ·mol -1. The sorption behavior of HD-2 for La(Ⅲ) obeys the Freundlich isotherm. The adsorption parameters of thermodynamic are ΔH=9.56 kJ·mol -1, ΔS=35.7 J·mol -1·K -1, ΔG=-1.08 kJ·mol -1, respectively.

DCHA AS A NEW REAGENT FOR THE ESTERIFICATION OF OBSTINATED AMINO ACIDS BY THE MERRIFIELD'S RESIN

The obstinated amino acid,Boc-Asn(or Boc-Gln),was directly anchored onto the Merrifield's resin using DCHA as the base in present reaction.The yield(71.88%)of Boc-Asn-OCH_2-resin was much better than those(0-33.5%)using Cs_2CO_3,KOH,KF.DEA and TEA as the base.which are efficient reagents for other amino acids in the same reaction.

Adsorption of Iminodiacetic Acid Resin for Lutetium

The adsorption behavior and mechanism of a novel chelate resin, iminodiacetic acid resin (IDAAR) for Lu(Ⅲ) were investigated. The statically saturated adsorption capacity is 210.8 mg·g^(-1) at 298 K in HAc-NaAc medium. The Lu(Ⅲ) adsorbed on IDAAR can be eluted by 0.5 mol·L^(-1) HCl and the elution percentage reaches 96.5%. The resin can be regenerated and reused without obvious decrease in adsorption capacity. The apparent adsorption rate constant is k_(298)=2.0×10^(-5) s^(-1). The adsorption behavior of IDAAR for Lu(Ⅲ) obeys the Freundlich isotherm. The thermodynamic adsorption parameters, enthalpy change ΔH, free energy change ΔG and entropy change ΔS of IDAAR for Lu(Ⅲ) are 13.1 kJ·mol^(-1), -1.37 kJ·mol^(-1) and 48.4 J·mol^(-1)·K^(-1), respectively. The apparent activation energy is E_a=31.3 kJ·mol^(-1). The molar coordination ratio of the functional group of IDAAR to Lu(Ⅲ) is about 3∶1. The adsorption mechanism of IDAAR for Lu(Ⅲ) was examined by chemical method and IR spectrometry.

SYNTHESIS, STRUCTURE AND PROPERTIES OF INTERPENETRATING SULFONIC ACID RESINS WITH HIGH CAPACITY

Two series of interpenetrating sulfonic acid resins (ISAR), 10×n and n×10, were prepared by means of the wet method, and the physicochemical, thermodynamic and kinetic properties of the ISAR were measured. The results show: 10×n resins exhibit better properties than n×10 ones, mainly in higher apparent degree of crosslinking and larger conformational entropy effect, among which, 10×1 resin exhibits the best thermodynamic and kinetic properties. In the DTA graphs of n×10 resins, there are two T_g and two T_(ox), but in those of 10×n, only one T_g and one T_(ox). This result well supports the conclusion that 10×n resins have much better interpenetrating structural aspects.

TRIFLUOROMETHANESULFONIC ACID AS A USEFUL REAGENT FOR CLEAVAGEOF PEPTIDYL RESIN

The efficiency of TFMSA as a cleaving reagent for peptidyl resin(I-VIII)was evaluated by quantitative ninhydrin test of peptide substitution degree(SD)on resin.Under different conditions,such as variation of C-terminal residue,resin linkage,the temperature and reaction time etc.,TFMSA can be used very conveniently instead of HF in many cases.

Kinetics of Reaction of Bromo-epoxy Resin with Oleic Acid catalyzed by Dimethyl benzyl amine

The kinetics of reaction of bromo-epoxy resin with oleic acid in the presence of dimethylbenzylamine catalyst was studied. The reaction is a zero order reaction with respect to oleic acid, first order with respect to epoxy group and 0. 74 order with respect to dimethylbenzylamine. The reaction rate constants at various temperatures and activation energy were determined. The mechanism of this reaction was discussed. Keywords Tetrabromobisphenol-A, Bromo-epoxy resin, Oleic acid kinetics, Reaction mechanism

USE OF CATION EXCHANGE RESIN IN SYNTHESIS OF N-SUBSTITUTED-1-AMINOALKANEPHOSPHONATE AND-PHOSPHINIC ACIDS

Strongly acidic cation exchange resin(1x1,H form)has been successfully used as a catalyst in synthesis of diphenyl N-benzyloxycarbonyl-1-aminobenzylphosphonate, N-benzyloxycarbonyl-1-aminobenzylphenylphosphinic acid and N-p-tolylsulfonyl-1-aminobenzyl phenylphosphinic acid in high yields.

Is there a role of lipid-lowering therapies in the management of fatty liver disease?

Atherogenic dyslipidemia is characterized by increased triglyceride-rich lipoproteins and low high-density lipoprotein cholesterol concentrations.It is highly prevalent in non-alcoholic fatty liver disease(NAFLD)and contributes to the increased cardiovascular risk associated with this condition.Alongside insulin resistance it plays an important pathogenetic role in NAFLD/non-alcoholic steatohepatitis(NASH)development and progression.It has been shown that cholesterol-lowering reduces cardiovascular risk more in NAFLD vs non-NAFLD high-risk individuals.This evidence highlights the importance of effective lipid modulation in NAFLD.In this narrative review the effects of the most commonly used lipid-lowering therapies on liver outcomes alongside their therapeutic implications in NAFLD/NASH are critically discussed.Preclinical and clinical evidence suggests that statins reduce hepatic steatosis,inflammation and fibrosis in patients with NAFLD/NASH.Most data are derived from observational and small prospective clinical studies using changes in liver enzyme activities,steatosis/fibrosis scores,and imaging evidence of steatosis as surrogates.Also,relevant histologic benefits were noted in small biopsy studies.Atorvastatin and rosuvastatin showed greater benefits,whereas data for other statins are scarce and sometimes conflicting.Similar studies to those of statins showed efficacy of ezetimibe against hepatic steatosis.However,no significant anti-inflammatory and anti-fibrotic actions of ezetimibe have been shown.Preclinical studies showed that fibrates through peroxisome proliferator-activated receptor(PPAR)αactivation may have a role in NAFLD prevention and management.Nevertheless,no relevant benefits have been noted in human studies.Species-related differences in PPARαexpression and its activation responsiveness may help explain this discrepancy.Omega-3 fatty acids reduced hepatic steatosis in numerous heterogeneous studies,but their benefits on hepatic inflammation and fibrosis have not been established.Promising preliminary data for the highly purified eicosapentaenoic acid require further confirmation.Observational studies suggest that proprotein convertase subtilisin/kexin9 inhibitors may also have a role in the management of NAFLD,though this needs to be established by future prospective studies.

离子排斥色谱用于厌氧消化处理的水中脂肪族羧酸的分析(英文)

The analysis of seven aliphatic carboxylic acids(formic,acetic,propionic,iso-butyric,n-butyric,iso-valeric and n-valeric acid) in anaerobic digestion process waters for biogas production was examined by ion-exclusion chromatography with dilute acidic eluents(benzoic acid,perfluorobutyric acid(PFBA) and sulfuric acid) and non-suppressed conductivity/ultraviolet(UV) detection.The columns used were a styrene/divinylbenzene-based strongly acidic cation-exchange resin column(TSKgel SCX) and a polymethacrylate-based weakly acidic cation-exchange resin column(TSKgel Super IC-A/C).Good separation was performed on the TSKgel SCX in shorter retention times.For the TSKgel Super IC-A/C,peak shape of the acids was sharp and symmetrical in spite of longer retention times.In addition,the mutual separation of the acids was good except for iso-and n-butyric acids.The better separation and good detection was achieved by using the two columns(TSKgel SCX and TSKgel Super IC-A/C connected in series),lower concentrations of PFBA and sulfuric acid as eluents,non-suppressed conductivity detection and UV detection at 210 nm.This analysis was applied to anaerobic digestion process waters.The chromatograms with conductivity detection were relatively simpler compared with those of UV detection.The use of two columns with different selectivities for the aliphatic carboxylic acids and the two detection modes was effective for the determination and identification of the analytes in anaerobic digestion process waters containing complex matrices.

Adsorption behavior of ytterbium (Ⅲ) on gel-type weak acid resin

The adsorption and desorption behaviors of Yb（Ⅲ） on gel-type weak acid resin （110） were investigated. The influence of operational conditions such as contact time,initial concentration of Yb（Ⅲ）,initial pH of solution and temperature on the adsorption of Yb（Ⅲ） were also examined. The results showed that the optimal adsorption condition of 110 resin for Yb（Ⅲ） was achieved at pH=5.5 in HAc-NaAc medium. The maximum uptake capacity of Yb（Ⅲ） was 265.8 mg/g at 298 K. Yb（Ⅲ） could be eluted by using 3.0 mol/L HCl solution and the 110 resin could be regenerated and reused. The adsorption of Yb（Ⅲ） followed the Langmuir isotherm,and the correlation coefficients were evaluated. Various thermodynamic parameters such as standard enthalpy change （△H）,standard entropy change （△S） and standard free energy change （△G） were evaluated. The adsorption of Yb（III） on the 110 resin was found to be endothermic in nature. Thomas model was successfully applied to experimental data to predict the breakthrough curves and to determine the characteristics parameters of the column useful for process design. And the resin sample both before and after adsorption was described by IR spectroscopy.

Preparation and application of a novel orotic acid chelating resin for removal of Cu(Ⅱ) in aqueous solutions

A novel chelating resin OABA,capable of removing Cu（Ⅱ） from aqueous solution,was synthesized via the reaction of macroporous chloromethylated PS-DVB copolymer beads with orotic acid.The elemental analysis（EA）,Fourier transform infrared spectroscopy（FT-IR）,and scanning electron microscopy microscope-energy dispersive X-ray spectroscopy（SEM-EDS） were used in the characterization of the synthesized chelating resin.Multiple,static batch adsorption experiments were conducted at different initial concentrations and temperatures.OABA showed good adsorption capacity for Cu（Ⅱ） and the equilibrium data could be well matched with the Freundlich isotherm model.Coexisting sodium chloride and calcium chloride in solutions favored the Cu（Ⅱ） adsorption.Moreover,the desorption process of Cu（Ⅱ） was tested and over 90%regeneration efficiency for the spent OABA was achieved at ammonia concentrations ranging from 1.0%to 2.0%.The results suggested that OABA would be a potential alternative adsorbent for Cu（Ⅱ）,even with other heavy metal ion treatments of wastewater.