Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
Más filtros










Base de datos
Tipo de estudio
Intervalo de año de publicación
1.
ACS Omega ; 9(6): 6888-6893, 2024 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-38371768

RESUMEN

With climate change and environmental issues, the emissions of CO2 and its greenhouse effect have become a focal point. At present, the utilization of CO2 includes its synthesis into chemicals and fuels such as methane, methanol, and CO. CO2 utilization can be achieved through carbon capture and storage technologies, which involve capturing CO2 from industrial emissions and storing it to reduce the CO2 concentration in the atmosphere. However, these CO2 capture and utilization technologies still face challenges, such as technical immaturity and high costs. One of the CO2 capture and utilization technologies is the production of energy storage materials. In this study, CO2 captured by molten salt was used as the carbon source, and TiO2 nanotube arrays were used as precursors. Titanium carbide nanotube arrays(TiC-NTAs)with high specific surface area and high conductivity were prepared by electrolysis. Afterward, the electrochemical energy storage performance of TiC in different electrolytes was tested. The results show that reducing the ionic radius of the electrolyte is conducive to increasing the area-specific capacitance of the device and that the degradation of the cycle life of the quasi-solid supercapacitor may be caused by an increase in the internal resistance due to the loss of water from the electrolyte. This study provides a reference value for the low-temperature synthesis of nanometal carbides and the selection of electrolytes.

2.
Pol J Pathol ; 74(3): 182-193, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37955537

RESUMEN

S100 calcium-binding protein A16 (S100A16) has previously been reported to play a role in tumor cells. Nevertheless, the role that S100A16 played in nephroblastoma cells remains obscure. The expression of S100A16 and DEPDC1 were detected via RT-q PCR and western blotting. Cell transfection was performed to overexpress DEPDC1 or interfere S100A16. CCK8 was applied for the assessment of cell viability. The apoptotic level and the capabilities of WiT49 cells to proliferate, invade and migrated were appraised utilizing Tunel, colony formation Transwell, and wound healing, separately. The angiogenesis was estimated through tube formation assay. Co-immunoprecipitation (CO-IP) was performed to examine the targeted binding of S100A16 to DEPDC1. The contents of PI3K/Akt/mTOR pathway-related proteins were resolved by virtue of western blot. S100A16 and DEPDC1 expression levels were significantly increased in nephroblastoma cell lines. S100A16 deletion suppressed nephroblastoma cell proliferative, invasive, migrative and angiogenetic capabilities but facilitated the apoptotic level. Moreover, S100A16 could bind DEPDC1, DEPDC1 overexpression partially reversed the inhibitory effect of S100A16 interference on nephroblastoma cell. DEPDC1 overexpression also partially counteracted the suppressive impacts of S100A16 interference on PI3K/Akt/mTOR pathway-related proteins. S100A16 synergistic with DEPDC1 promotes the progression and angiogenesis of nephroblastoma cell through the PI3K/Akt/mTOR pathway.


Asunto(s)
Proteínas Proto-Oncogénicas c-akt , Tumor de Wilms , Humanos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Línea Celular Tumoral , Serina-Treonina Quinasas TOR/metabolismo , Tumor de Wilms/genética , Proteínas de Neoplasias/metabolismo , Proteínas Activadoras de GTPasa/metabolismo , Proteínas S100/metabolismo
3.
Materials (Basel) ; 16(17)2023 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-37687667

RESUMEN

Ultra-high Temperature Oxidation-Resistant Alloys (UTORAs) have received a lot of attention due to the increased research demand for deep space exploration around the world. However, UTORAs have the disadvantages of easy oxidation and chalking. So, in this study, a UTORAs is prepared by hot-press sintering on VZrHfNbTa (HEA: High Entropy Alloys can generally be defined as more than five elements by the equal atomic ratio or close to the equal atomic ratio alloying, the mixing entropy is higher than the melting entropy of the alloy, generally forming a high entropy solid solution phase of a class of alloys.) a substrate coated with hafnium. The bonding mechanism, resistance to high-temperature oxidation, and hardness of the sample tests are carried out. The results show that zirconium in the matrix will diffuse into the hafnium coating during the high-temperature sintering process and form the HfZr alloy transition layer, the coating thickness of the composite is about 120 µm, and the diffusion distance of zirconium in the hafnium coating is about 60 µm, this transition layer chemically combines the hafnium coating and the HEA substrate into a monolithic alloy composite. The results of high-temperature oxidation experiments show that the oxidation degree of the hafnium-coated VZrHfNbTa composite material is significantly lower than that of the VZrHfNbTa HEA after oxidation in air at 1600 °C for 5 h. The weight gain of the coated sample after oxidation is 56.56 mg/cm2, which is only 57.7% compared to the weight gain of the uncoated sample (98.09 mg/cm2 for uncoated), and the surface of the uncoated HEA shows obvious dents, oxidation, and pulverization occurred on the surface and interior of the sample. In contrast, the coated composite alloy sample mainly undergoes surface oxidation sintering to form a dense HfO2 protective layer, and the internal oxidation of the hafnium-coated VZrHfNbTa composite alloy is significantly lower than that of the uncoated VZrHfNbTa HEA.

4.
Front Microbiol ; 14: 1141418, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37234544

RESUMEN

Introduction: Proteus mirabilis is a multi-host pathogen that causes diseases of varying severity in a wide range of mammals, including humans. Proteus mirabilis is resistant to multiple antibiotics and has acquired the ability to produce expanded spectrum of ß-lactamases, leading to serious public health problems. However, the available information on P. mirabilis isolated from feces of dogs, is still poorly understood, as is the correlation between its virulence-associated genes (VAGs) and antibiotic resistance genes (ARGs). Method: In this study, we isolated 75 strains of P. mirabilis from 241 samples, and investigated the swarming motility, biofilm formation, antimicrobial resistance (AMR), distribution of VAGs and ARGs, as well as the presence of class 1, 2, and 3 integrons in these isolates. Results: Our findings suggest a high prevalence of intensive swarming motility and strong biofilm formation ability among P. mirabilis isolates. Isolates were primarily resistant to cefazolin (70.67%) and imipenem (70.67%). These isolates were found to carry ureC, FliL, ireA, zapA, ptA, hpmA, hpmB, pmfA, rsbA, mrpA, and ucaA with varying prevalence levels of 100.00, 100.00, 100.00, 98.67, 98.67, 90.67, 90.67, 90.67, 90.67, 89.33, and 70.67%, respectively. Additionally, the isolates were found to carry aac(6')-Ib, qnrD, floR, blaCTX-M, blaCTX-M-2, blaOXA-1, blaTEM, tetA, tetB and tetM with varying prevalence levels of 38.67, 32.00, 25.33, 17.33, 16.00, 10.67, 5.33, 2.67, 1.33, and 1.33%, respectively. Among 40 MDR strains, 14 (35.00%) were found to carry class 1 integrons, 12 (30.00%) strains carried class 2 integrons, while no class 3 integrons was detected. There was a significant positive correlation between the class 1 integrons and three ARGs: blaTEM, blaCTX-M, and blaCTX-M-2. This study revealed that P. mirabilis strains isolated from domestic dogs exhibited a higher prevalence of MDR, and carried fewer VAGs but more ARGs compared to those isolated from stay dogs. Furthermore, a negative correlation was observed between VAGs and ARGs. Discussion: Given the increasing antimicrobial resistance of P. mirabilis, veterinarians should adopt a prudent approach towards antibiotics administration in dogs to mitigate the emergence and dissemination of MDR strains that pose a potential threat to public health.

5.
Genes (Basel) ; 14(4)2023 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-37107653

RESUMEN

Circular RNAs (circRNAs) are a newly discovered class of endogenously expressed non-coding RNAs (ncRNAs). They are highly stable, covalently closed molecules that frequently exhibit tissue-specific expression in eukaryotes. A small number of circRNAs are abundant and have been remarkably conserved throughout evolution. Numerous circRNAs are known to play important biological roles by acting as microRNAs (miRNAs) or protein inhibitors ('sponges'), by regulating the function of proteins, or by being translated themselves. CircRNAs have distinct cellular functions due to structural and production differences from mRNAs. Recent advances highlight the importance of characterizing circRNAs and their targets in a variety of insect species in order to fully understand how they contribute to the immune responses of these insects. Here, we focus on the recent advances in our understanding of the biogenesis of circRNAs, regulation of their abundance, and biological roles, such as serving as templates for translation and in the regulation of signaling pathways. We also discuss the emerging roles of circRNAs in regulating immune responses to various microbial pathogens. Furthermore, we describe the functions of circRNAs encoded by microbial pathogens that play in their hosts.


Asunto(s)
MicroARNs , ARN Circular , Animales , ARN Circular/genética , ARN Circular/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , ARN Mensajero , Insectos/genética , Insectos/metabolismo , Sistema Inmunológico/metabolismo
6.
RSC Adv ; 12(35): 22881-22892, 2022 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-36105980

RESUMEN

Perovskites with flexible structures and excellent redox properties have attracted considerable attention in industry, and their denitration activities can be further improved with metal substitution. In order to investigate the effect of Ce and Cu substitution on the physicochemical properties of perovskite in NH3-SCR system, a series of La1-x Ce x Mn1-y Cu y O3 (x = 0, 0.1, y = 0, 0.05, 0.1, 0.2, 0.4) catalysts were prepared by citrate sol-gel method and employed for NO removal in the simulated flue gas, and the physical and chemical properties of the catalysts were studied using XRD, SEM, BET, XPS, DRIFT characterizations. The Ce substitution on A-site cation of LaMnO3 can improve the denitration activity of the perovskite catalyst, and La0.9Ce0.1MnO3 displays NO conversion of 86.7% at 350 °C. The characterization results indicate that the high denitration activity of La0.9Ce0.1MnO3 is mainly attributed to the larger surface area, which contributes to the adsorption of NH3 and NO. Besides, the appropriate Cu substitution on B-site cation of La0.9Ce0.1MnO3 can further improve the denitration activity of perovskite catalyst, and La0.9Ce0.1Mn0.8Cu0.2O3 displays the NO conversion of 91.8% at 350 °C. Although the specific surface area of La0.9Ce0.1Mn0.8Cu0.2O3 is lower than La0.9Ce0.1MnO3, the Cu active sites and the Ce3+ contents are more developed, making many reaction units formed on the catalyst surface and redox properties of catalyst improved. In addition, strong metal interaction (Ce4+ + Mn2+ + Cu2+ ↔ Ce3+ + Mn3+/Mn4+ + Cu+) and high concentrations of chemical adsorbed oxygen and lattice oxygen both strengthen the redox reaction on catalyst surface, thus contributing to the better denitration activity of La0.9Ce0.1Mn0.8Cu0.2O3. Therefore, appropriate cerium and copper substitution will markedly improve the denitration activity of La-Mn perovskite catalyst. We also reasonably conclude a multiple reaction mechanism during NH3-SCR denitration process basing on DRIFT results, which includes the Eley-Rideal mechanism and Langmuir-Hinshelwood mechanism.

7.
Biotechnol Lett ; 44(7): 845-855, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35614284

RESUMEN

Hfq is an RNA-binding protein, its main function is to participate in post-transcriptional regulation of bacteria and regulate small regulatory RNA (sRNA) and messenger RNA (mRNA) stability, but the Hfq function of Bacillus subtilis (B. subtilis) has not been fully explained. In this study, we used the strains of B. subtilis168 (BS168), BS168Δhfq and BS168Δhfq-C to explore the effects of Hfq on the glucose utilization, biofilm formation and quorum sensing (QS) system of B. subtilis. The results showed that the knockout of hfq resulted in growth defects when bacteria were cultured in the Luria-Bertani (LB) medium, but we did not observe the same effects in Nitrogen medium (NM) and Inorganic Salt-free medium (ISM). We further found that the growth of strains under different glucose concentrations was also different, which was related to the expression of CcpA. Interestingly, the hfq mutant showed increased resistance to a high-glucose environment. Furthermore, the biofilm and extracellular poly saccharides (EPS) formation of BS168Δhfq decreased significantly. At the same time, changes were observed in the morphology of the biofilm, such as larger intercellular space of the biofilm and thinner edge. The qRT-PCR results confirmed that the hfq knockout caused significant up-regulation or down-regulation of gene expression in QS system, and down-regulated genes were involved in the positive regulation of biofilm formation. Taken together, we demonstrated that Hfq plays a vital role in glucose utilization, biofilm formation and QS of B. subtilis, which provides a new perspective for subsequent related research.


Asunto(s)
Bacillus subtilis , Percepción de Quorum , Bacillus subtilis/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Biopelículas , Regulación Bacteriana de la Expresión Génica , Glucosa/metabolismo , Percepción de Quorum/genética
8.
Dalton Trans ; 51(21): 8279-8289, 2022 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-35579562

RESUMEN

In this work, a photoelectrochemical (PEC) aptasensor for detecting kanamycin (KAN) was designed based on an aptamer modified Bi/BiOBr/titania nanorod array (TiO2 NRA). Bi/BiOBr was loaded onto the TiO2 NRA via a one-pot solvothermal method using glucose as a reductant. The p-n heterojunction structure constructed from chrysanthemums like BiOBr and the TiO2 NRA improves the electron transfer rate. Combined with metal Bi with the surface plasmon resonance (SPR) effect, it further increases the absorption range of visible light and enhances the light response performance of the PEC aptasensor. The KAN aptamer is fixed to the Bi/BiOBr/TiO2 NRA photoelectric material through the CN structure. Once the aptamer precisely captures KAN molecules, photocurrent changes are generated to realize the detection of KAN. The designed PEC aptasensor shows good detection performance in the linear response range of 1 pM-200 nM, and the detection limit is 0.7 pM (S/N = 3). The aptasensor was applied to the determination of KAN in milk with satisfactory results.


Asunto(s)
Aptámeros de Nucleótidos , Técnicas Biosensibles , Nanotubos , Aptámeros de Nucleótidos/química , Bismuto , Técnicas Electroquímicas/métodos , Kanamicina , Límite de Detección , Nanotubos/química , Titanio
10.
Langmuir ; 38(7): 2276-2286, 2022 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-35138855

RESUMEN

Developing a photoactive material by combining the characteristics of a wide light response range and effective separation of photogenerated electron-hole pairs remains a huge challenge for the construction of a photoelectrochemical (PEC) sensing platform. Herein, a gold nanoparticle (AuNP)/MoS2/TiO2 composite was prepared through the facile hydrothermal method coupled with an in situ photoreduction technology. Benefiting from both the compositional and structure merits, the composite not only extends the absorption range to visible light but also enhances the photoelectric conversion efficiency by transferring photogenerated electrons into the conduction band of semiconductors from the plasmonic AuNP. Meanwhile, the thiolated aptamers were attached to the surface of AuNP/MoS2/TiO2 composites through the Au-S bonding to construct a visible light driven PEC aptasensor for ultrasensitive detection chloramphenicol (CAP). In the presence of CAP, the aptamers anchored on the surface of the photoactive materials could specifically recognize CAP and interact with it to form a bioaffinity complex with a steric hindrance effect, resulting in the rapid decrease of photocurrent responses. Based on this photocurrent suppression strategy, the constructed PEC aptasensing platform exhibited a high sensitivity with a wide linear range from 5 pM to 100 nM and a low detection limit of 0.5 pM.


Asunto(s)
Aptámeros de Nucleótidos , Técnicas Biosensibles , Nanopartículas del Metal , Aptámeros de Nucleótidos/química , Cloranfenicol , Técnicas Electroquímicas/métodos , Oro/química , Luz , Límite de Detección , Nanopartículas del Metal/química , Molibdeno/química , Titanio
11.
Biotechnol Lett ; 43(9): 1779-1785, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34129180

RESUMEN

OBJECTIVE: To study the function of the RNA-binding protein Hfq in Bacillus subtilis cellulose decomposition. RESULTS: In the medium with sodium carboxymethylcellulose (Na-CMC) as the sole carbon source, the knockout of Hfq resulted in a 38.0% ± 2.1% and 76.6% ± 7.1% decrease in cellulose hydrolysis ability and cellulase activity, respectively. The results of real-time quantitative PCR revealed that several cellulase genes (eglS, bglA, and bglC) were significantly downregulated in the Hfq knockout strain. The isogenic Δhfq complemented strain recovered the cellulose hydrolysis ability, cellulase activity, and expression level of cellulase genes. In addition, the survival of Hfq mutant in stationary phase was significantly affected. CONCLUSION: RNA-binding protein Hfq is involved in the regulation of cellulose hydrolysis ability, cellulase activity, cellulase gene expression, and stationary phase survival.


Asunto(s)
Bacillus subtilis/crecimiento & desarrollo , Celulasa/genética , Celulosa/química , Proteína de Factor 1 del Huésped/genética , Bacillus subtilis/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Carboximetilcelulosa de Sodio/química , Celulasa/metabolismo , Medios de Cultivo/química , Regulación hacia Abajo , Regulación Bacteriana de la Expresión Génica , Técnicas de Inactivación de Genes , Proteína de Factor 1 del Huésped/metabolismo , Hidrólisis
12.
Mater Sci Eng C Mater Biol Appl ; 119: 111521, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33321608

RESUMEN

Magnesium alloys can work as biomedical materials due to their Young's modules similar to that of bone. Nevertheless, in a human plasma, one of the major drawbacks of these materials is the low corrosion resistance. Here, AZ80 corrosion in the solutions containing chloride, bicarbonate, sulphate and hydrogen phosphate ions were investigated by a short-term immersion test and electrochemical techniques. The results showed that bicarbonate and hydrogen phosphate could retard corrosion rate, while chloride and sulphate accelerated corrosion rate. During the early immersion stage, the corrosion rate increased with the presence of bicarbonate. It was caused by the reaction of bicarbonate and hydroxide promoting the dissolution of magnesium and accelerating corrosion. In the later stage, the reduced corrosion rate was due to the formation of various protective films. The sample formed a new sparse porous MgSO4·5H2O compounds in the sulphate ion solution, which could not effectively prevent chloride ions from entering the matrix and thus accelerated the dissolution of magnesium. With the presence of hydrogen phosphate, magnesium phosphate with a much lower solubility was formed, preferentially precipitated on the surface and was not influenced by the chloride ions. The corrosion mechanisms of magnesium alloys in above ions were proposed.


Asunto(s)
Aleaciones , Magnesio , Materiales Biocompatibles , Corrosión , Humanos , Iones , Ensayo de Materiales , Propiedades de Superficie
13.
RSC Adv ; 12(1): 378-388, 2021 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-35424492

RESUMEN

This study aims to investigate the enhanced low temperature denitration activity and promotional mechanism of a cerium-based catalyst through copper modification. In this paper, copper and cerium oxides were supported on TiO2-ZrO2 by an impregnation method, their catalytic activity tests of selective catalytic reduction (SCR) of NO with NH3 were carried out and their physicochemical properties were characterized. The CuCe/TiO2-ZrO2 catalyst shows obviously enhanced NH3-SCR activity at low temperature (<300 °C), which is associated with the well dispersed active ingredients and the synergistic effect between copper and cerium species (Cu2+ + Ce3+ ↔ Cu+ + Ce4+), and the increased ratios of surface chemisorbed oxygen and Cu+/Cu2+ lead to the enhanced low-temperature SCR activity. The denitration reaction mechanism over the CuCe/TiO2-ZrO2 catalyst was investigated by in situ DRIFTS and DFT studies. Results illustrate that the NH3 is inclined to adsorb on the Cu acidic sites (Lewis acid sites), and the NH2 and NH2NO species are the key intermediates in the low-temperature NH3-SCR process, which can explain the promotional effect of Cu modification on denitration activity of Ce/TiO2-ZrO2 at the molecular level. Finally, we have reasonably concluded a NH3-SCR catalytic cycle involving the Eley-Rideal mechanism and Langmuir-Hinshelwood mechanism, and the former mechanism dominates in the NH3-SCR reaction.

14.
Phys Chem Chem Phys ; 22(41): 23743-23753, 2020 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-33057548

RESUMEN

Carbon nanotubes (CNT)-cerium oxide (CeO2) nanocomposites were fabricated successfully by one-pot microwave hydrothermal growth of regular CeO2 nanoparticles with a size of 8 nm on hydroxyl-functionalized multi-walled CNTs. These nanocomposite photocatalysts demonstrated an acid orange (AO7) photocatalytic degradation efficiency of above 90% under solar-simulated light irradiation for 3 h, which was much higher than that of the pure CeO2 nanoparticles. The enhanced photocatalytic activity was observed to mainly originate from the ˙O2- and hole traps, while the hydroxyl radical ˙OH played a secondary role.

15.
Langmuir ; 36(33): 9658-9667, 2020 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-32787068

RESUMEN

C-doped ZnO particles have been successfully prepared by the calcination using microwave hydrothermally prepared metal-organic framework-5 (MOF-5) as the precursor. MOF-5 was turned into C-doped ZnO through calcination at 500 °C, and its cubic shape was well-maintained. X-ray photoelectron spectroscopic studies confirmed the C-doping in the ZnO. The as-prepared C-doped ZnO demonstrated a Rhodamine B (RhB) degradation efficiency of 98% in 2 h under an solar-simulated light irradiation, much higher than that of C-doped ZnO derived from MOF-5 synthesized by the ordinary hydrothermal method. The trapping experiment revealed that the crucial factors in the RhB removal were photogenerated h+ and •O2-.

16.
Chemosphere ; 259: 127389, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32590175

RESUMEN

Metal-organic frameworks (MOFs) are promising for photocatalysis owing to their excellent structure and performance. Unfortunately, poor stability in both aqueous solutions and high temperatures and lack of adsorption centers during reactions limit their practical applications. Herein, a bimetallic MOF anchored corncob calcined derived activated carbon (CCAC) was successfully prepared by a one-step solvothermal method. Benefiting from unique structures and synergetic effect, the porous carbon provided a high specific surface area for stable MOF support and served as an organic pollutant buffer-reservoir, which was advantageous for efficient photocatalytic degradation of organic pollutants. The optimized MOF/CCAC-5 samples possessed excellent visible light degradation rate, i.e., 100% for Rh B, more than 96% for six mixed dyes, and 98% for tetracycline. This prominent photocatalytic activity was caused by active species, including photoelectrons (e-), photo-holes (h+) and superoxide free radicals (•O2-). The transient photocurrent response and electrochemical impedance tests showed that MOF/CCAC-5 exhibited a relatively high charge separation and low carrier recombination rate. Cyclic and simulation experiments indicated high reusability, stability and universality of the composite photocatalysts. These exciting results provide new pathways for the fabrication of MOFs anchored porous carbon materials.


Asunto(s)
Contaminantes Ambientales/química , Estructuras Metalorgánicas , Adsorción , Catálisis , Carbón Orgánico , Colorantes , Luz , Porosidad , Zea mays
17.
Int J Biol Macromol ; 162: 310-319, 2020 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-32569682

RESUMEN

CuS/ZnS/sodium alginate/reduced graphene oxide nanocomposites (CZSrG) were prepared by physical crosslinking followed by one-step reduction and were justified as green binder-free hydrogel high-capacitance electrodes. The physical crosslinking was realized simply through the hydrogen-bond interaction between sodium alginate (SA) and graphene oxide (GO), avoiding the usage of traditional Ca2+ crosslinking agent. The hydrogel structure made of CZSrG possessed the most beneficial effect of avoiding large volume change and increasing cycle stability for supercapacitors. When used as electrode, the specific capacitance of CZSrG was 992 F·g-1 (10 mV·s-1) in a three-electrode system. Furthermore, the fabricated supercapacitors had a specific capacitance of 252.1 F·g-1 (5 mV·s-1), and a power density of 1800 Wh·kg-1 at the energy density of 2.05 Wh·kg-1. Thus, the CZSrG has a favorable electrochemical performance and wide application prospects in supercapacitors.


Asunto(s)
Alginatos/química , Cobre/química , Capacidad Eléctrica , Electroquímica/métodos , Grafito/química , Nanogeles/química , Sulfuros/química , Compuestos de Zinc/química , Reactivos de Enlaces Cruzados/química , Electroquímica/instrumentación , Electrodos , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Nanocompuestos/química , Nanocompuestos/ultraestructura , Nanogeles/ultraestructura , Sulfuros/síntesis química , Compuestos de Zinc/síntesis química
18.
Int J Biol Macromol ; 152: 576-583, 2020 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-32105684

RESUMEN

Polyacrylamide (PAM) has been used as a coagulant aid in water treatment process for past decades, but it has caused great damages to human nervous system. Developing new coagulant aid with high biological safety is urgently demanded. This study provides a natural biomacromolecule coagulant aid with good biosecurity-Enteromorpha prolifera polysaccharide (Ep). Its coagulant aid efficiency and mechanism were investigated in terms of organics removal, floc properties and membrane fouling degree. In addition, contrast experiments were conducted with PAM to evaluate its potential of industrial applications. Results showed that organics removal could be increased by 23% when 0.3 mg/L Ep was used, which exhibited comparable aid effects to PAM. Due to the bridging-sweep aid role of Ep, flocs sizes, growth rate and recovery factor reached 470 µm, 62.6 µm/min and 0.492, respectively, while only 170 µm, 14.0 µm/min and 0.326 were obtained by PAM. Additionally, flocs exhibited more porous and multi-branched structures when Ep was applied, which caused less ultrafiltration membrane fouling (eventual J/J0 value = 0.52). As a result, Ep could be considered as a potential substitute of PAM, since better biosecurity, higher organics removal and lower membrane fouling could be obtained simultaneously by Ep addition.


Asunto(s)
Incrustaciones Biológicas/prevención & control , Sustancias Húmicas , Membranas Artificiales , Polisacáridos/química , Ultrafiltración/métodos , Ulva/química , Resinas Acrílicas , Coagulantes/química , Floculación , Cinética , Espectroscopía de Resonancia Magnética , Ensayo de Materiales , Polímeros/química , Espectroscopía Infrarroja por Transformada de Fourier , Purificación del Agua/métodos
19.
ChemSusChem ; 13(10): 2522-2539, 2020 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-32045509

RESUMEN

Sodium-ion capacitors (SICs), designed to attain high energy density, rapid energy delivery, and long lifespan, have attracted much attention because of their comparable performance to lithium-ion capacitors (LICs), alongside abundant sodium resources. Conventional SIC design is based on battery-like anodes and capacitive cathodes, in which the battery-like anode materials involve various reactions, such as insertion, alloying, and conversion reactions, and the capacitive cathode materials usually depend on activated carbon (AC). However, researchers have attempted to construct SICs based on battery-like cathodes and capacitive anodes or a combination of both in recent years. In this Minireview, charge storage mechanisms and material design strategies for SICs are summarized, with a focus on the battery-like anode materials from both inorganic and organic sources. Additionally, the challenges in the fabrication of SICs and future research directions are discussed.

20.
Phys Chem Chem Phys ; 22(9): 5114-5122, 2020 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-32073008

RESUMEN

Recently, flexible metacomposites with negative permittivity have triggered extensive interest owing largely to their promising applications in areas such as sensors, cloaking, and wearable and flexible electronic devices. In this paper, flexible silver nanowire/carbon fiber felt (AgNW/CFF) metacomposites with weakly negative permittivity were fabricated by adjusting their composition and microstructure. Along with the formation of a conductive AgNW network, the resulting composites gradually presented metal-like behavior. Interestingly, weakly negative permittivity with a small absolute value (as low as about 6.4) and good flexibility were observed in the composites with 3.7 wt% AgNWs. The one-dimensional silver nanowires contribute to reducing the overall electron density of the resulting composites, which is responsible for the weakly negative permittivity. As the AgNWs increased, the Drude-like negative permittivity got stronger owing to the enhancement of the electron density. Further investigation from the perspective of microelectronics revealed that the negative permittivity is dependent on the inductive characteristic. The proposed design strategy for AgNW/CFF composites with tunable negative permittivity opens up a new approach to flexible metacomposites.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...