RESUMO
The removal of phosphate ions by capacitive deionization has become one of the most frontier research topics in the water treatment field in recent years. In this work, hybrid electrodes composed of nickel-iron layered double hydroxide (NiFe-LDH) - anchored on activated carbon fiber (ACF)-were synthesized by a hydrothermal method and subsequently applied in capacitive deionization to remove phosphate ions. The adsorption performance of the two hybrid electrodes on phosphate ions was compared by capacitive deionization experiments. The experiment was carried out for 3 hours to reach equilibrium, and the optimum adsorption of 33.48 mg/g was obtained using NiFe-LDH/ACF-2 hybrid electrode at room temperature (25 °C) and pH = 6.0. The results showed that increasing the loading capacity of NiFe-LDH on ACF might enhance the adsorption capacity of phosphate ions. Furthermore, the calculation of adsorption kinetics and adsorption isotherms elucidated that the adsorption capacity increased with the increasing of applied voltage. Meanwhile, the experimental data were fitted well with pseudo-first-order kinetics and Langmuir isotherms. Notably, it was observed that the pH first increased, then decreased during the adsorption due to the electrolysis of water, while the form of phosphate ions was transformed, with low pH favoring the adsorption of phosphate ions.
Assuntos
Purificação da Água , Eletrodos , Purificação da Água/métodos , Adsorção , Hidróxidos , Fosfatos , Carvão Vegetal , Fibra de Carbono , ÍonsRESUMO
The cathode material is critical to the yield of hydrogen peroxide (H2O2) and electro-Fenton (EF) performance. In this work, bismuth oxychloride (BiOCl) as one of the representatives of ternary oxides was grown in situ on carbon felt (CF) through a simple solvothermal method and employed directly as a self-standing cathode for the EF degradation of the target contaminant tetracycline (TC). TC can be almost completely degraded, up to 95% in 90 min under the heterogeneous EF process. The characterizations demonstrated that the BiOCl/CF electrode exhibited excellent conductivity due to CF as the supporting carbon material with a 3D network structure; meanwhile, this hybrid electrode also possessed abundant active sites attributed to the decorated BiOCl having rich oxygen defects. Finally, the rational reaction mechanism of TC was also elucidated by the X-ray photoelectron spectroscopy (XPS) spectrum, free radical quenching experiments and electron paramagnetic resonance (EPR) spectra, in which hydroxyl radicals (c OH) were considered as the dominant active oxidants and BiOCl had a synergistic effect on in-situ generation and decomposition of H2O2.
Assuntos
Carbono , Poluentes Químicos da Água , Antibacterianos , Bismuto , Eletrodos , Peróxido de Hidrogênio/química , Oxirredução , Tetraciclina/química , Poluentes Químicos da Água/químicaRESUMO
A series of LaNiO3 perovskite nanoparticles with different morphologies, such as spheres, rods and cubes, were prepared through co-precipitation and hydrothermal methods, and used as the catalysts for peroxydisulfate (PDS) activation. The physical and chemical characterization of LaNiO3 perovskites was performed, including X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen isotherm absorption (BET), electrochemical impedance spectroscopy (EIS), and X-ray photoelectron spectroscopy (XPS). The LaNiO3 with different shapes showed different activities in Acid Orange 7 (AO7) degradation. Sphere-like LaNiO3 exhibited the highest catalytic activity, which is probably due to the largest specific surface area, higher proportion of reductive Ni2+ and the higher electron transfer ability. The radical scavenging experiments and electron paramagnetic resonance (EPR) revealed the production of massive sulfate radicals (SO4â¢-) and hydroxyl radicals (â¢OH) during the oxidation. Finally, the possible mechanisms of PDS activation and AO7 degradation were proposed. The prepared LaNiO3 perovskites also showed excellent reusability and stability.
Assuntos
Poluentes Ambientais , Nanopartículas , Catálise , Radical Hidroxila , Espectroscopia FotoeletrônicaRESUMO
Phosphate residue is a kind of hazardous solid waste and if not properly disposed of, could cause serious environmental contaminations. The abundant iron salt available in phosphate residue can be used to prepare photo-Fenton catalytic reagent for wastewater treatment. In this study, the phosphate residue was effectively purified by a hydrothermal recrystallization method, reaching an iron phosphate purity of 94.2%. The particles of iron phosphate were further processed with ball milling with their average size reduced from 19.4 to 1.6 µm. By hydrothermal crystallization of iron phosphate and thermal decomposition of oxalate precursor, porous iron hydroxy phosphate was prepared. The modified porous iron hydroxy phosphate (m-PIHP) of higher surface area with iron oxalate on its surface can degrade 98.87% of Rhodamine B in 15 min. Cyclic experiment showed that the catalyst still had a good catalytic activity after six cycles (>40%). The X-ray photoelectron spectroscopy results showed that the iron oxalate complex on the catalyst surface decomposed to produce ferrous ions and accelerated the rate of â¢OH production. The current work demonstrated that the m-PIHP synthesized from phosphate residue and modified with iron oxalate can be used as an effective dye wastewater treatment agent.
Assuntos
Ferro , Fosfatos , Catálise , Peróxido de Hidrogênio , Compostos Orgânicos , PorosidadeRESUMO
Macrophages are key components of the innate immune system and play pivotal roles in immune response, organ development, and tissue homeostasis. Studies in mice and zebrafish have shown that tissue-resident macrophages derived from different hematopoietic origins manifest distinct developmental kinetics and colonization potential, yet the genetic programs controlling the development of macrophages of different origins remain incompletely defined. In this study, we use zebrafish, where tissue-resident macrophages arise from the rostral blood island (RBI) and ventral wall of dorsal aorta (VDA), the zebrafish hematopoietic tissue equivalents to the mouse yolk sac and aorta-gonad-mesonephros for myelopoiesis, to address this issue. We show that RBI- and VDA-born macrophages are orchestrated by distinctive regulatory networks formed by the E-twenty-six (Ets) transcription factors Pu.1 and Spi-b, the zebrafish ortholog of mouse spleen focus forming virus proviral integration oncogene B (SPI-B), and the helix-turn-helix DNA-binding domain containing protein Irf8. Epistatic studies document that during RBI macrophage development, Pu.1 acts upstream of Spi-b, which, upon induction by Pu.1, partially compensates the function of Pu.1. In contrast, Pu.1 and Spi-b act in parallel and cooperatively to regulate the development of VDA-derived macrophages. Interestingly, these two distinct regulatory networks orchestrate the RBI- and VDA-born macrophage development largely by regulating a common downstream gene, Irf8. Our study indicates that macrophages derived from different origins are governed by distinct genetic networks formed by the same repertoire of myeloid-specific transcription factors.
Assuntos
Linhagem da Célula/imunologia , Regulação da Expressão Gênica no Desenvolvimento , Redes Reguladoras de Genes , Macrófagos/imunologia , Proteínas Proto-Oncogênicas/imunologia , Transativadores/imunologia , Peixe-Zebra/imunologia , Sequência de Aminoácidos , Animais , Aorta/citologia , Aorta/crescimento & desenvolvimento , Aorta/imunologia , Diferenciação Celular , Linhagem da Célula/genética , Embrião não Mamífero , Humanos , Imunidade Inata , Fatores Reguladores de Interferon/genética , Fatores Reguladores de Interferon/imunologia , Macrófagos/citologia , Mesonefro/citologia , Mesonefro/crescimento & desenvolvimento , Mesonefro/imunologia , Camundongos , Especificidade de Órgãos , Isoformas de Proteínas/genética , Isoformas de Proteínas/imunologia , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-ets/genética , Proteínas Proto-Oncogênicas c-ets/imunologia , Transdução de Sinais , Transativadores/genética , Saco Vitelino/citologia , Saco Vitelino/crescimento & desenvolvimento , Saco Vitelino/imunologia , Peixe-Zebra/genética , Peixe-Zebra/crescimento & desenvolvimentoRESUMO
To realize the error parameter estimation of strap-down inertial navigation system (SINS) and improve the navigation accuracy for aircraft, a hybrid improved restricted Boltzmann machine BP neural network (IRBM-BPNN) approach, which combines restricted Boltzmann machine (RBM) and BP neural network (BPNN), is proposed to forecast the inertial measurement unit (IMU) instrument errors and initial alignment errors of SINS. Firstly, the error generation mechanism of SINS is analyzed, and initial alignment error model and IMU instrument error model are established. Secondly, an unsupervised RBM method is introduced to initialize BPNN to improve the forecast performance of the neural network. The RBM-BPNN model is constructed through the information fusion of SINS/GPS/CNS integrated navigation system by using the sum of position deviation, the sum of velocity deviation and the sum of attitude deviation as the inputs and by using the error parameters of SINS as the outputs. The RBM-BPNN structure is improved to enhance its forecast accuracy, and the pulse signal is increased as the input of the neural network. Finally, we conduct simulation experiments to forecast and compensate the error parameters of the proposed IRBM-BPNN method. Simulation results show that the artificial neural network method is feasible and effective in forecasting SINS error parameters, and the forecast accuracy of SINS error parameters can be effectively improved by combining RBM and BPNN methods and improving the neural network structure. The proposed IRBM-BPNN method has the optimal forecast accuracy of SINS error parameters and navigation accuracy of aircraft compared with the radial basis function neural network method and BPNN method.
RESUMO
In this work, quinone-modified metal-organic framework MIL-101(Fe)(Q-MIL-101(Fe)), as a novel heterogeneous Fenton-like catalyst, was synthesized for the activation of persulfate (PS) to remove bisphenol A (BPA). The synthetic Q-MIL-101(Fe) was characterized via X-ray diffraction, scanning electron microscope, Fourier transform infrared, electrochemical impedance spectroscopy, cyclic voltammetry and X-ray photoelectron spectroscopy. As compared to the pure MIL-101(Fe), Q-MIL-101(Fe) displayed better catalytic activity and reusability. The results manifested that the Q-MIL-101(Fe) kept quinone units, which successfully promoted the redox cycling of Fe3+/Fe2+ and enhanced the removal efficiency. In addition, the reaction factors of Q-MIL-101(Fe) were studied (e.g. pH, catalyst dosage, PS concentration and temperature), showing that the optimum conditions were [catalyst] = 0.2 g/L, [BPA] = 60 mg/L, [PS] = 4 mmol/L, pH = 6.79, temperature = 25 °C. On the basis of these findings, the probable mechanism on the heterogeneous activation of PS by Q-MIL-101(Fe) was proposed.
Assuntos
Complexos de Coordenação , Estruturas Metalorgânicas , Poluentes Químicos da Água/química , QuinonasRESUMO
In this study, a novel composite containing an iron based metal-organic framework (MOF) and BiOBr was successfully synthesized by a simple method, and was fully characterized by X-ray diffraction patterns, Fourier transform infrared spectra, UV-vis diffuse reflectance spectra, and transmission electron microscopy. Moreover, the photocatalytic activities of BiOBr/MIL-88B(Fe) composites and the pure materials were evaluated by measuring the degradation of Rhodamine B under visible light. The results show that the composite exhibits better photocatalytic activities than pure materials, which can be ascribed to the high adsorption capacity of MIL-88B(Fe) and the enhanced separation of photogenerated charge carriers from assembly of MIL-88B(Fe) on BiOBr. And the effects of various operating parameters such as catalyst dosage, medium pH, the mass ratio of BiOBr, and MIL-88B(Fe) and the dye initial concentration on the degradation of RhB have been studied.
Assuntos
Bismuto/química , Compostos de Ferro/química , Processos Fotoquímicos , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da ÁguaRESUMO
In this study, cobalt etched graphite felt electrodes were produced using a simple etching technique. It was used in combination with a solid polymer electrolyte (SPE) for the degradation of the target contaminant Orange II by Electro-Fenton (EF) technique in low conductivity water. In this method, 94% of Orange II in low conductivity water was removed in 90 min. The characterization analysis substantiates the hypothesis that the electrodes produced exhibit a three-dimensional porous structure, augmented defect concentration, and enhanced electron transfer capability. In addition, the potential reaction mechanism was inferred from the radical quenching experiments, and hydroxyl radicals (·OH) were deemed the main reactive substances. The combination of cobalt etched graphite felt electrodes with SPE demonstrates remarkable efficacy in the treatment of organic wastewater characterized by low electrical conductivity.
Assuntos
Compostos Azo , Benzenossulfonatos , Grafite , Poluentes Químicos da Água , Grafite/química , Cobalto , Polímeros , Eletrodos , Água , Poluentes Químicos da Água/química , Peróxido de Hidrogênio/química , OxirreduçãoRESUMO
OBJECTIVE: To describe the characterization of a novel deletion causing α-thalassemia. METHODS: The proband, a 30-year-old female, displayed mild anemia from thalassemia screening. Gap-PCR was used to detect the four common deletional α-thalassemia, and a PCR-reverse dot blot was performed for the three point mutations of the α-globin gene. Multiplex ligation-dependent probe amplification (MLPA) was used to query possible breakpoints of a potential novel deletion. Third-generation sequencing (TGS) was used to identify the novel deletion after the MLPA failed. Gap-PCR and Sanger sequencing were validated for the breakpoint. RESULTS: No abnormal results were detected by Gap-PCR and PCR-reverse dot blot. MLPA only showed a large deletion upstream of the HBZ-1 probe, but the scope could not be determined. However, a novel 107 kb deletion at the α-globin gene was discovered by the TGS. The Gap-PCR products with the specific breakpoint fragment of the 107 kb deletion were confirmed by Sanger sequencing. CONCLUSIONS: A 107 kb deletion causing α-thalassemia was the first reported worldwide. TGS played an important role in this study and can be recommended as a reliable tool for rare or potential deletions in thalassemia.
Assuntos
Talassemia alfa , Feminino , Humanos , Adulto , Talassemia alfa/genética , Talassemia alfa/diagnóstico , alfa-Globinas/genética , Família Multigênica , Reação em Cadeia da Polimerase Multiplex , Mutação Puntual , Deleção de Genes , Deleção de Sequência/genéticaRESUMO
A series of FeMn bimetallic ferrocene-based metal-organic frameworks (FeMn-Fc-MOFs) with various molar ratios of Fe and Mn (1:9, 2:8, 4:6, 6:4) were successfully synthesized using a simple hydrothermal synthesis method and employed as an efficient activator on persulfate (PS) activation for water decontamination. Characterizations demonstrated that Fe and Mn were smoothly introduced into ferrocene-based MOFs and various molar ratios of Fe:Mn had some influence on crystallinity and surface structure of FeMn-Fc-MOFs. Within 120 min, Fe4Mn6-Fc-MOFs demonstrated the best catalytic activity among the different molar ratios, and acid orange 7(AO7) degradation rate was up to 92.0%. In addition, electrochemical experiments revealed that Fe4Mn6-Fc-MOFs possessed superior electron transfer capability than other FeMn-Fc-MOFs, leading to better catalytic performance. Moreover, quenching tests and electron paramagnetic resonance (EPR) detection indicated that hydroxyl radicals and sulfate radicals were both responsible for AO7 decomposition. Notably, the redox cycle of Fe(II)/Fe(III) and Mn(II)/Mn(IV) was discovered in the Fe4Mn6-Fc-MOFs/PS system, which was considered as the limiting process for the cleavage of the O-O bond in PS to generate active radicals. Ultimately, the Fe4Mn6-Fc-MOFs exhibits an excellent universality and good cycling stability for 5 continuous runs. This paper broadens the application of ferrocene-based MOFs on heterogeneous PS activation in environmental catalysis.
Assuntos
Poluentes Ambientais , Estruturas Metalorgânicas , Estruturas Metalorgânicas/química , Compostos Férricos , Metalocenos , Compostos Ferrosos , CatáliseRESUMO
OBJECTIVE: The 4.2â kb deletion (-α4.2/) is a common a+-thalassemia with a carrier rate, followed by the South-East Asian deletion (-SEA) and the 3.7â kb deletion (-α3.7/). There are few reports about 4.2â kb deletion sub-types. Herein, we present a patient with double heterozygous -α4.2â /-α4.2â ¡who was identified using third-generation sequencing (TGS). METHODS: Hematology and hemoglobin fraction analysis were carried out by complete blood count (CBC) and capillary electrophoresis (CE). Gap-PCR was used to detect the common deletional α-thalassemia, and multiple ligation-dependent probe amplification (MLPA) was performed to screen the large deletion. Sanger sequencing identified the variant. The different deletions were confirmed by TGS. RESULTS: CBC showed the patient with microcytic hypochromic anemia, and CE indicated the presence of a Hb variant. Gap-PCR and MLPA detected 4.2â kb deletion homozygotes (-α4.2/-α4.2). The Hb variant was confirmed as Hb Q-Thailand by Sanger sequencing. The patient was identified as compound heterozygous of 4.2â kb deletion and Hb Q-Thailand (-α4.2/-α4.2-Q-Thailand, -α4.2â /-α4.2â ¡) using TGS. CONCLUSIONS: Hb Q-Thailand (-α4.2-Q-Thailand/) complex 4.2â kb deletion heterozygote (-α4.2/) is easily misdiagnosed as 4.2â kb homozygous using Gap-PCR and MLPA. The TGS enables the identification of the two different 4.2â kb deletion sub-types.
Assuntos
Anemia Hipocrômica , Humanos , Anemia Hipocrômica/genética , Povo Asiático , Eletroforese Capilar , Heterozigoto , Homozigoto , Análise de Sequência de DNARESUMO
This work presents the role of commercial microfiltration membranes combined with single particle inductively coupled plasma-mass spectrometry (SP-ICP-MS) in removing environmental matrix interference for model silver nanoparticles (AgNPs) determination. The filters with different pore sizes (0.22 µm, 0.45 µm, 0.8 µm) and materials (mixed cellulose ester, polyether sulfone, and nylon) were investigated to acquire the recovery of particle concentration and size of AgNPs spiked into different real aqueous solutions, including ultrapure water, tap water, surface water, and sewage effluent. The maximum recovery of nanoparticle concentration was 70.2% through the 0.8 µm polyether sulfone membrane. The heated filters were able to improve the recovery of AgNPs particle concentration in the real aqueous environment. Hence, the pretreatment method by SP-ICP-MS combined with filtration membrane was simple, fast, and low-cost to quantify AgNPs in natural water environments.
RESUMO
AIMS: Alpha-thalassaemia is one of the most common monogenic disorders worldwide. Due to high guanine-cytosine (GC) content and high mutation diversity in α-globin gene cluster, deletional and non-deletional mutations were usually separately detected with different methods. The aim of this study was to develop a novel one-step method for α-thalassaemia genotyping. METHODS: A multiplex symmetric PCR melting curve strategy was designed for one-step α-thalassaemia genotyping. Based on this strategy, a novel method was developed to simultaneously detect four common deletional (-α3.7 , -α4.2 , _ _SEA , --THAI ) and five common non-deletional (αCD30(-GAG)α, αCD31(G>A)α, αWSα, αQSα, αCSα) α-thalassaemia mutations in a closed-tube reaction. This method was also evaluated by double-blind detection of 235 genotype-known samples and 1630 clinical samples. RESULTS: All nine α-thalassaemia mutations could be accurately identified by this novel method within 3 hours. The evaluation results also showed a 100% concordance with comparison methods. CONCLUSIONS: This method is rapid, accurate, low-cost and easy to operate, which can be used for molecular screening and genetic diagnosis of α-thalassaemia in clinical practice. The multiplex symmetric PCR melting curve strategy designed in this study can also provide an effective approach to the method development for high GC content templates and multiple mutations.
Assuntos
Talassemia alfa , Humanos , Talassemia alfa/diagnóstico , Talassemia alfa/genética , Genótipo , Mutação , Reação em Cadeia da Polimerase Multiplex , alfa-Globinas/genéticaRESUMO
Understanding how the morphology of a layered double hydroxide (LDH)-based catalyst alters its catalytic activity provides an available strategy for the rational design and fabrication of high-efficiency catalysts at a micro-scale. Herein, three nickel-iron layered double hydroxide (NiFe-LDH) catalysts including 2D-plate-like hexagon (P-NiFe-LDH), 2D/3D-flower-like solid sphere (FS-NiFe-LDH), and 2D/3D-flower-like hollow sphere (FH-NiFe-LDH) with regulable oxygen vacancies (OVs) were fabricated via a morphological regulation method of Ostwald ripening. The experimental results demonstrated that the three types of NiFe-LDH exhibited different abilities to activate persulfate (PS) for the abatement of acid orange 7 (AO7) with a sequence of FH-NiFe-LDH > FS-NiFe-LDH > P-NiFe-LDH. Particularly, the FH-NiFe-LDH with a hollow structure exhibited the most considerable activity with the first-order rate constant up to k = 0.02639 min-1, benefiting from the highly accessible surface areas, higher intrinsic activity of the exposed crystal planes, and abundant OVs. Characterizations further confirmed that these properties could profoundly allow for more exposure of active sites and enhance the reactivity of OV-connected Ni or Fe to facilitate electron transfer and generate more reactive radicals, therefore elucidating the morphologic origin of catalytic performance. Based on the quenching experiments, sulfate radicals (SO4·-), hydroxyl radicals (·OH), and oxygen radicals (O2·-) were identified to be involved in the decomposition process. Furthermore, the continuous redox cycle of Ni(II)/Ni(III)/Ni(II) and Fe(II)/Fe(III)/Fe(II) was responsible for the generation of active radicals via activating PS.
Assuntos
Compostos Férricos , Níquel , Níquel/química , Espécies Reativas de Oxigênio , Hidróxidos/química , Oxirredução , Sulfatos , Ferro/química , Oxigênio , Compostos FerrososRESUMO
Ferrocene-based metal-organic framework with different transition metals (M-Fc-MOFs, M = Fe, Mn, Co) was synthesized by a simple hydrothermal method and used as a heterogeneous catalyst for persulfate activation. The samples were characterized by X-ray diffraction, transmission electron microscopy, X-ray electron spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. Meanwhile, the influences of factors such as catalyst dosage, persulfate concentration, and pH on the degradation of acid orange 7 (AO7) were studied in detail. The results showed that hollow cobalt-based ferrocenyl metal-organic framework microspheres (Co-Fc-MOFs) exhibited the best catalytic performance, which is closely related to the synergy of Fc/Fc+ and Co(II)/Co(III) cycles in persulfate activation. Free radical quenching studies indicated that both sulfate and hydroxyl appeared to contribute to the degradation of AO7.
Assuntos
Compostos Azo/química , Benzenossulfonatos/química , Estruturas Metalorgânicas , Poluentes Químicos da Água , Metalocenos , Microesferas , Poluentes Químicos da Água/químicaRESUMO
Goethite is the most ubiquitous iron oxide mineral in soils, and adsorption of organic pollutants on goethite dominates the fate and transportation in the environment. In this study, the facet-dependent adsorption behavior of ciprofloxacin (CIP) on goethite was systematically investigated with in situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectra and two-dimensional correlation analysis (2D-COS). The experimental results indicated that the goethite samples with higher facet proportion of {021}/{110} exhibited the better adsorption capacity compared to goethite with lower facet proportion of {021}/{110}. The reason is the more existence of singly coordinated sites with higher reactivity on the {021} facet. Moreover, CIP was found to be adsorbed on {021} and {110} facets by forming a tridentate complex involving the bridge coordination of bidentate ligands, H-bonding, and a bidentate chelate complex.
Assuntos
Ciprofloxacina , Compostos de Ferro , Adsorção , Antibacterianos , Concentração de Íons de Hidrogênio , Minerais , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
The decomposition of levofloxacin was performed in an aqueous solution under ultrasound irradiation. The effect of operating conditions, including pH value, reaction time, initial concentration, and ultrasound power on the chemical oxygen demand (COD) removal rate was examined at room temperature (23 +/- 2 degrees C). Under a given condition (initial levofloxacin concentration = 20 mg/L, ultrasonic power = 400 W, and pH = 5.86), a 56.6% COD removal rate was obtained after 120 minutes of reaction time. It also was found that 5-day biochemical oxygen demand (BOD5) of the solution increased evidently after sonochemical treatment, and the ratio of BOD5/COD, which was a good measure for biodegradability, increased from 0 to 0.40, indicating that the biodegradability of the solution was enhanced. Based on the results, it is feasible that sonochemical oxidation can be used for the pretreatment of levofloxacin effluent before biological treatment processes.
Assuntos
Antibacterianos/química , Levofloxacino , Ofloxacino/química , Ultrassom , Eliminação de Resíduos Líquidos/métodos , Tetracloreto de Carbono/química , Concentração de Íons de Hidrogênio , terc-Butil Álcool/químicaRESUMO
OBJECTIVE: To enhance the dissolution rate of daidzein with solid dispersion technique. METHOD: Solid dispersions were prepared by the solvent method using water-solubility chitosan as a hydrophilic carrier. DSC, IR and X-ray methods were used to verify the formation of solid dispersion. RESULT: Dissolution percentages of solid dispersions were more than 90 percent in the drug-carrier ratio of 1:5 and 1:9. But dissolution percentages of physical mixtures and pure drug were 40 and 38.4 percent respectively. Part of daidzein dispersed in solid dispersion in the form of microcrystalline. CONCLUSION: Water-soluble chitosan solid dispersion can significantly increase dissolution rate of daidzein.
Assuntos
Quitosana/química , Isoflavonas/química , Água/química , Varredura Diferencial de Calorimetria , Solubilidade , Espectrofotometria Infravermelho , Difração de Raios XRESUMO
In this work, four novel defective MIL-101(Fe) catalysts with coordinatively unsaturated sites were successfully prepared via a facile synthesis strategy by employing benzoic acid, acetic acid, oxalic acid, or citric acid as a modulator. The modified catalysts were demonstrated the existence of defects in the parent framework by a series of characterizations. As compared to the initial MIL-101(Fe), the electronic structure of defective MIL-101(Fe) catalyst was effectively adjusted; meanwhile, the coordinatively unsaturated Fe sites were efficiently generated and the pore sizes were enlarged. Besides, the defective MIL-101(Fe) catalysts exhibited excellent catalytic performance for rhodamine B degradation by persulfate activation. To be specific, the degradation rates of rhodamine B increased from 58.70 to 94.05%, 86.11%, 78.70%, and 82.62%, respectively. The defective MIL-101(Fe) with coordinatively unsaturated sites showed good reusability and stability, and the probable catalytic mechanism was also investigated.