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1.
J Environ Sci (China) ; 127: 833-843, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36522111

RESUMO

Compared with the traditional liquid-liquid extraction method, solid-phase extraction agents are of great significance for the recovery of indium metal due to their convenience, free of organic solvents, and fully exposed activity. In this study, P2O4 (di-2-ethylhexyl phosphoric acid) was chemically modified by using UiO-66 to form the solid-phase extraction agent P2O4-UiO-66-MOFs (di-2-ethylhexyl phosphoric acid-UiO-66-metal-organic frameworks) to adsorb In(III). The results show that the Zr of UiO-66 bonds with the P-OH of P2O4 to form a composite P2O4-UiO-66-MOF, which was confirmed by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). The adsorption process of indium on P2O4-UiO-66-MOFs followed pseudo first-order kinetics, and the adsorption isotherms fit the Langmuir adsorption isotherm model. The adsorption capabilities can reach 192.8 mg/g. After five consecutive cycles of adsorption-desorption-regeneration, the indium adsorption capacity by P2O4-UiO-66-MOFs remained above 99%. The adsorption mechanism analysis showed that the P=O and P-OH of P2O4 molecules coated on the surface of P2O4-UiO-66-MOFs participated in the adsorption reaction of indium. In this paper, the extractant P2O4 was modified into solid P2O4-UiO-66-MOFs for the first time. This work provides a new idea for the development of solid-phase extractants for the recovery of indium.


Assuntos
Estruturas Metalorgânicas , Estruturas Metalorgânicas/química , Índio , Espectroscopia de Infravermelho com Transformada de Fourier , Extração em Fase Sólida/métodos , Adsorção
2.
Wei Sheng Wu Xue Bao ; 55(9): 1144-53, 2015 Sep 04.
Artigo em Zh | MEDLINE | ID: mdl-26762027

RESUMO

OBJECTIVE: We analyzed the transcriptional regulation of aco gene cluster and the phenotype of acoR mutant, to determine the effect of acoR deletion on sporulation efficiency and Cry protein production. METHODS: Sequence of aco gene cluster in Bacillus thuringiensis was analyzed by sequence alignment. RT-PCR was carried out to reveal the transcriptional units of the aco gene cluster. acoR insertion mutant was constructed by homologous recombination. Transcriptional activity was analyzed by promoter fusions with lacZ gene. Comparison of the Cry1Ac protein production was determined by protein quantitation. RESULTS: The aco gene cluster was composed of four genes. The acoABCL formed one transcriptional unit. The transcriptional activity of acoA promoter sharply decreased in sigL and acoR mutants, respectively. Deletion of acoR had no effect on growth and Cry protein production, but decreased the motility of cells and sporulation efficiency. CONCLUSION: The aco gene cluster is controlled by Sigma 54 and activated by AcoR. Deletion of acoR has no effect on Cry protein production, but decreased the motility of the cells.


Assuntos
Bacillus thuringiensis/genética , Proteínas de Bactérias/genética , Regulação Bacteriana da Expressão Gênica , Família Multigênica , Bacillus thuringiensis/metabolismo , Proteínas de Bactérias/metabolismo , Deleção de Genes , Regiões Promotoras Genéticas , Transcrição Gênica
3.
Materials (Basel) ; 17(8)2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38673146

RESUMO

The development of a new generation of solid particle solar receivers (SPSRs) with high solar absorptivity (0.28-2.5 µm) and high infrared emissivity (1-22 µm) is crucial and has attracted much attention for the attainment of the goals of "peak carbon" and "carbon neutrality". To achieve the modulation of infrared emission and solar absorptivity, two types of medium- and high-entropy rare-earth hexaboride (ME/HEREB6) ceramics, (La0.25Sm0.25Ce0.25Eu0.25)B6 (MEREB6) and (La0.2Sm0.2Ce0.2Eu0.2Ba0.2)B6 (HEREB6), with severe lattice distortions were synthesized using a high-temperature solid-phase method. Compared to single-phase lanthanum hexaboride (LaB6), HEREB6 ceramics show an increase in solar absorptivity from 54.06% to 87.75% in the range of 0.28-2.5 µm and an increase in infrared emissivity from 76.19% to 89.96% in the 1-22 µm wavelength range. On the one hand, decreasing the free electron concentration and the plasma frequency reduces the reflection and ultimately increases the solar absorptivity. On the other hand, the lattice distortion induces changes in the B-B bond length, leading to significant changes in the Raman scattering spectrum, which affects the damping constant and ultimately increases the infrared emissivity. In conclusion, the multicomponent design can effectively improve the solar energy absorption and heat transfer capacity of ME/HEREB6, thus providing a new avenue for the development of solid particles.

4.
Materials (Basel) ; 17(10)2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38793275

RESUMO

The use of solar interface evaporation for seawater desalination or sewage treatment is an environmentally friendly and sustainable approach; however, achieving efficient solar energy utilization and ensuring the long-term stability of the evaporation devices are two major challenges for practical application. To address these issues, we developed a novel ceramic fiber@bioderived carbon composite aerogel with a continuous through-hole structure via electrospinning and freeze-casting methods. Specifically, an aerogel was prepared by incorporating perovskite oxide (Ca0.25La0.5Dy0.25)CrO3 ceramic fibers (CCFs) and amylopectin-derived carbon (ADC). The CCFs exhibited remarkable photothermal conversion efficiencies, and the ADC served as a connecting agent and imparted hydrophilicity to the aerogel due to its abundant oxygen-containing functional groups. After optimizing the composition and microstructure, the (Ca0.25La0.5Dy0.25)CrO3 ceramic fiber@biomass-derived carbon aerogel demonstrated remarkable properties, including efficient light absorption and rapid transport of water and solutes. Under 1 kW m-2 light intensity irradiation, this novel material exhibited a high temperature (48.3 °C), high evaporation rate (1.68 kg m-2 h-1), and impressive solar vapor conversion efficiency (91.6%). Moreover, it exhibited long-term stability in water evaporation even with highly concentrated salt solutions (25 wt%). Therefore, the (Ca0.25La0.5Dy0.25)CrO3 ceramic fiber@biomass-derived carbon aerogel holds great promise for various applications of solar interface evaporation.

5.
Microbiol Res ; 235: 126438, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32088504

RESUMO

Acetoin (3-hydroxy-2-butanone) is an important physiological metabolic product in many microorganisms. Acetoin breakdown is catalyzed by the acetoin dehydrogenase enzyme system (AoDH ES), which is encoded by acoABCL operon. In this study, we analyzed transcription and regulation of the aco operon in Bacillus thuringiensis (Bt). RT-PCR analysis revealed that acoABCL forms one transcriptional unit. The Sigma 54 controlled consensus sequence was located 12 bp from the acoA transcriptional start site (TSS). ß-galactosidase assay revealed that aco operon transcription is induced by acetoin, controlled by sigma 54, and positively regulated by AcoR. The HTH domain of AcoR recognized and specifically bound to a 13-bp inverted repeat region that participates in 30-bp fragment mapping 81 bp upstream of the acoA TSS. The GAF domain in AcoR represses enhancer transcriptional activity at the acoA promoter. Transcriptions of the aco operon and acoR were repressed by glucose via CcpA, and CcpA specifically bound to sequences within the acoR promoter fragment. In the acoABCL and acoR mutants, acetoin use was abolished, suggesting that the aco operon is essential for utilization of acetoin. The data presented here improve our understanding of the regulation of the aco gene cluster in bacteria.


Assuntos
Acetoína/metabolismo , Bacillus thuringiensis/genética , Proteínas de Bactérias/genética , Regulação Bacteriana da Expressão Gênica , Família Multigênica , Transcrição Gênica , Bacillus thuringiensis/metabolismo , Redes e Vias Metabólicas/genética , Óperon
6.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 28(3): 918-926, 2020 Jun.
Artigo em Zh | MEDLINE | ID: mdl-32552958

RESUMO

OBJECTIVE: To investigation the types and frequencies of thalassemia gene mutations in pregnant population in Nanping area of Fujian Province, so as to provide a basis for prevention and control of birth children with moderate and severe thalassaemia in this area. METHODS: The genotyping of α and ß thalassemia was performed using the gap-PCR (gap-PCR) technique combined with reverse dot blot (RDB). The genotyping test was performed by Gap-PCR for three rare deficient thalassemia. The cases with negative detection were further detected by Sanger sequencing method, so as to identify rare α or ß thalassemia mutation. RESULTS: 1120 specimens were genotyped for thalassemia, out of them 547 thalassemia genes were determined. The detection rate was 48.8% (547/1120). 340 specimens were diagnosed as α thalassemia, and the detection rate was 30.6%, including 266 cases of --SEA/αα, 44 cases of -α3.7/αα, 12 cases of -α4.2/αα, 8 cases of ααQS/αα,. 3 cases of Hb H disease ( 2 cases of --SEA/-α3.7, 1 case of --SEA/-α4.2), 2 cases of ααCS/αα, 2 cases of ααWS/αα, 1 case of -α3.7/-α3.7, and 1 case of -α3.7/ααQS. Also, they contain 11 cases of rare α thalassemia, 8 kinds of rare types of α thalassemia mutations in combination, such as 4 cases of ααIVS-II-55 (T→G) in α1/αα, 1 case of ααIVS-I-62 (C→T) in α1/αα, 1 case of ααCD106(CTG→GTG)in α2/αα, 1 case of ααHBA2:c.-24C>G/αα, 1 case of ααIVS-II-55 (T→G) in α1/ααIVS-II-55 (T→G) in α1, 1 case of ααIVS-II-55 (T→G) in α1/ααIVS-II-119 (G;+CTCGGCCC) in α2, 1 case of ααIVS-II-88 (G→A) in α2/αα, and 1 case of --THAI/αα. Among them, 5 α mutation sites were first reported, namely ααIVS-I-62 (C→T) in α1, ααIVS-II-55 (T→G) in α1, ααIVS-II-119 (G; +CTCGGCCC ) in α2, ααIVS-II-88 (G→A) in α2 and ααCD106 (CTG→GTG) in α2; 2 α thalassemia mutation sites: ααHBA2: c.-24C>G and --THAI were detected again in the Chinese population, respectively. 188 specimens were diagnosed as ß thalassemia with a detection rate of 16.8%. Among them, 68 cases of ßIVS-II-654/ßN, 47 cases of ßCD41-42/ßN, 20 cases of ßCD17/ßN, 17 cases of ß-28/ßN, 7 cases of ßCD27-28/ßN, 7 cases of ßE/ßN, 3 cases of ßCD71-72/ßN and 2 cases of ßCD43/ßN. And 17 cases were diagnosed as rare ß thalassemia, 8 kinds of rare types were ß thalassemia mutations in combination. There were 4 cases of ßIVS-II-81 (C→T)/ßN, 3 cases of ßHb J-Bangkok/ßN, 3 cases of ßHb New York/ßN, 2 cases of ß-96 (G→T)/ßN, 2 cases of ßIVS-II-806 (G→C)/ßN, 1 case of ßCodons 8/9/ßN, 1 case of ßHb G-Coushatta/ßN, 1 case of ßIVS-II-827 (A→T)/ßN. Among them, 3 ß thalassemia mutation sites were reported for the first time, namely ß-96 (G→T), ßIVS-II-806 (G→C) and ßIVS-II-827 (A→T); it was found that in the Chinese population as ßCodons 8/9, ßHb G-Coushatta, ßHb J-Bangkok, ßHb New York, and ßIVS-II-81 (C→T), respectively. 19 cases were diagnosed as αß-complex thalassemia, out of which 15 types of thalassemia mutation combinations were detected. They contain 2 cases of rare αß-complex thalassemia, which are ααIVS-II-55 (T→G)/αα complex ßIVS-II-81 (C→T)/ßN, ααIVS-II-65 (G→A) in α1/αα complex ßHb G-Coushatta/ßN. CONCLUSION: The types of thalassemia gene mutations in Nanping area of Fujian province are genetically heterogeneous. The prevention and control strategies of thalassaemia in this area should be based on the prevention and treatment of common α thalassemia and ß thalassaemia. And the attention should be paid to the types of rare and unknown gene mutations using screening and testing method.


Assuntos
Talassemia alfa , Talassemia beta , China , Feminino , Genótipo , Humanos , Mutação , Gravidez , Tailândia , Talassemia alfa/genética , Talassemia beta/genética
7.
R Soc Open Sci ; 6(6): 190547, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31312503

RESUMO

Herein, we report the synthesis of a new type of porous Mo2C/C composite by using luffa sponge-derived carbon template and ammonium molybdate ((NH4)6Mo7O24•4H2O) in molten NaCl-KCl salt media. The product exhibits a higher specific surface area and three-dimensional porous structure, including macrochannels, micropores and mesopores. The desirable porous structure results from the carbon template structure and Mo2C coating formed.

8.
J Colloid Interface Sci ; 460: 264-72, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26343979

RESUMO

The ß-NaYF4:Yb(3+),Tm(3+)/g-C3N4 (NYT/C3N4) photocatalyst has been successfully fabricated by a stepwise method. Firstly, the advanced near-infrared (NIR) driven photocatalyst was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and UV-Vis-NIR diffuse reflectance spectroscopy. It was found that NYT/C3N4 photocatalyst consisted of uniform hexagonal phase NaYF4 nanocrystals with about 20nm diameter distributed on surface of g-C3N4 sheets, and the NYT/C3N4 composite exhibited strong near-infrared light absorption and the energy transfer from ß-NaYF4:Yb(3+),Tm(3+) to g-C3N4 was confirmed. Secondly, the photocatalytic activities of the catalysts were evaluated by the degradation of methyl blue dye and colorless phenol under the irradiation of 980nm laser. The results suggested that NYT/C3N4 nanocomposite is an advanced NIR-driven photocatalyst. Moreover the NYT/C3N4 photocatalyst showed good stability for photocatalytic decoloration of dye in the recycled tests. This study suggested a promising system to utilize the NIR energy of sunlight for photochemical and photoelectrical applications based on g-C3N4, which will contribute to the utilization of solar energy in the future.

9.
Biomed Microdevices ; 8(4): 309-15, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17003961

RESUMO

This paper proposes a cross-shaped micromixer featuring a pair barrier within the mixing channel. The proposed device obtains a rapid mixing of two sample fluids by means of the electrokinetic instability-induced shedding effects which are produced when a DC electric field of an appropriate intensity is applied. The proposed device uses a single high-voltage power source to simultaneously drive and mix the sample fluids. The effectiveness of the mixer is characterized experimentally as a function of the applied electric field intensity and the extent to which a pair barrier obstruct the mixing channel. The experimental results indicate that the mixing performance reaches 96% at a cross-section located 1 mm downstream of the cross-junction when an electric field of 300 V/cm is applied. The micromixing method presented in this study provides a simple low-cost solution to mixing problems in lab-on-a-chip systems.


Assuntos
Técnicas Analíticas Microfluídicas , Microfluídica , Cinética , Técnicas Analíticas Microfluídicas/instrumentação , Técnicas Analíticas Microfluídicas/métodos , Microfluídica/instrumentação , Microfluídica/métodos
10.
Electrophoresis ; 27(24): 4982-90, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17109376

RESUMO

This paper presents a T-shaped micromixer featuring 45 degrees parallelogram barriers (PBs) within the mixing channel. The presented device obtains a rapid mixing of two sample fluids with conductivity ratio of 10:1 (sample concentration:running buffer concentration) by means of the electrokinetic instability-induced shedding effects which are produced when a direct current (DC) electric field of an appropriate intensity is applied. The presented device uses a single high-voltage power source to simultaneously drive and mix the sample fluids. The effectiveness of the mixer is characterized experimentally as a function of the applied electrical field intensity and the extent to which the PBs obstruct the mixing channel. The experimental results indicate that the mixing performance reaches 91% at a cross-section located 2.3 mm downstream of the T-junction when the barriers obstruct 4/5 of the channel width and an electrical field of 300 V/cm is applied. The micromixing method presented in this study provides a simple low-cost solution to mixing problems in lab-on-a-chip systems.


Assuntos
Técnicas Analíticas Microfluídicas/instrumentação , Desenho de Equipamento
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