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1.
Adv Mater ; : e2310480, 2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38669281

RESUMEN

Conjugated polymers are promising materials for thermoelectric applications, however, at present few effective and well-understood strategies exist to further advance their thermoelectric performance. Here a new model system is reported for a better understanding of the key factors governing their thermoelectric properties: aligned, ribbon-phase poly[2,5-bis(3-dodecylthiophen-2-yl)thieno[3,2-b]thiophene] (PBTTT) doped by ion-exchange doping. Using a range of microstructural and spectroscopic methods, the effect of controlled incorporation of tie-chains between the crystalline domains is studied through blending of high and low molecular weight chains. The tie chains provide efficient transport pathways between crystalline domains and lead to significantly enhanced electrical conductivity of 4810 S cm-1, which is not accompanied by a reduction in Seebeck coefficient or a large increase in thermal conductivity. Respectable power factors of 173 µW m-1 K-2 are demonstrated in this model system. The approach is generally applicable to a wide range of semicrystalline conjugated polymers and could provide an effective pathway for further enhancing their thermoelectric properties and overcome traditional trade-offs in optimization of thermoelectric performance.

2.
Adv Mater ; : e2314062, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38558210

RESUMEN

Doping is a crucial strategy to enhance the performance of various organic electronic devices. However, in many cases, the random distribution of dopants in conjugated polymers leads to the disruption of the polymer microstructure, severely constraining the achievable performance of electronic devices. Here, it is shown that by ion-exchange doping polythiophene-based P[(3HT)1-x-stat-(T)x] (x = 0 (P1), 0.12 (P2), 0.24 (P3), and 0.36 (P4)), remarkably high electrical conductivity of >400 S cm-1 and power factor of >16 µW m-1 K-2 are achieved for the random copolymer P3, ranking it among highest ever reported for unaligned P3HT-based films, significantly higher than that of P1 (<40 S cm-1, <4 µW m-1 K-2). Although both polymers exhibit comparable field-effect transistor hole mobilities of ≈0.1 cm2 V-1 s-1 in the pristine state, after doping, Hall effect measurements indicate that P3 exhibits a large Hall mobility up to 1.2 cm2 V-1 s-1, significantly outperforming that of P1 (0.06 cm2 V-1 s-1). GIWAXS measurement determines that the in-plane π-π stacking distance of doped P3 is 3.44 Å, distinctly shorter than that of doped P1 (3.68 Å). These findings contribute to resolving the long-standing dopant-induced-disorder issues in P3HT and serve as an example for achieving fast charge transport in highly doped polymers for efficient electronics.

3.
Polymers (Basel) ; 16(3)2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38337280

RESUMEN

In this study, gold nanoparticles (AuNPs) were synthesized in situ using chitin nanogels (CNGs) as templates to prepare composites (CNGs@AuNPs) with good photothermal properties, wherein their drug release properties in response to stimulation by near-infrared (NIR) light were investigated. AuNPs with particle sizes ranging from 2.5 nm to 90 nm were prepared by varying the reaction temperature and chloroauric acid concentration. The photothermal effect of different materials was probed by near-infrared light. Under 1 mg/mL of chloroauric acid at 120 °C, the prepared CNGs@AuNPs could increase the temperature by 32 °C within 10 min at a power of 2 W/cm2. The Adriamycin hydrochloride (DOX) was loaded into the CNGs@AuNPs to investigate their release behaviors under different pH values, temperatures, and near-infrared light stimulations. The results showed that CNGs@AuNPs were pH- and temperature-responsive, suggesting that low pH and high temperature could promote drug release. In addition, NIR light stimulation accelerated the drug release. Cellular experiments confirmed the synergistic effect of DOX-loaded CNGs@AuNPs on chemotherapy and photothermal therapy under NIR radiation.

4.
Int J Parasitol ; 54(5): 213-223, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38185351

RESUMEN

The genomic evolution of Polyopisthocotylea remains poorly understood in comparison to the remaining three classes of Neodermata: Monopisthocotylea, Cestoda, and Trematoda. Moreover, the evolutionary sequence of major events in the phylogeny of Neodermata remains unresolved. Herein we sequenced the mitogenome and transcriptome of the polyopisthocotylean Diplorchis sp., and conducted comparative evolutionary analyses using nuclear (nDNA) and mitochondrial (mtDNA) genomic datasets of Neodermata. We found strong mitonuclear discordance in the phylogeny of Neodermata. Polyopisthocotylea exhibited striking mitonuclear discordance in relative evolutionary rates: the fastest-evolving mtDNA in Neodermata and a comparatively slowly-evolving nDNA genome. This was largely attributable to its very long stem branch in mtDNA topologies, not exhibited by the nDNA data. We found indications that the fast evolution of mitochondrial genomes of Polyopisthocotylea may be driven both by relaxed purifying selection pressures and elevated levels of directional selection. We identified mitochondria-associated genes encoded in the nuclear genome: they exhibited unique evolutionary rates, but not correlated with the evolutionary rate of mtDNA, and there is no evidence for compensatory evolution (they evolved slower than the rest of the genome). Finally, there appears to exist an exceptionally large (≈6.3 kb) nuclear mitochondrial DNA segment (numt) in the nuclear genome of newly sequenced Diplorchis sp. A 3'-end segment of the 16S rRNA gene encoded by the numt was expressed, suggesting that this gene acquired novel, regulatory functions after the transposition to the nuclear genome. In conclusion, Polyopisthocotylea appears to be the lineage with the fastest-evolving mtDNA sequences among all of Bilateria, but most of the substitutions were accumulated deep in the evolutionary history of this lineage. As the nuclear genome does not exhibit a similar pattern, the circumstances underpinning this evolutionary phenomenon remain a mystery.


Asunto(s)
Genoma Mitocondrial , Trematodos , Animales , Filogenia , ARN Ribosómico 16S , Trematodos/genética , ADN Mitocondrial/genética , Mitocondrias/genética
5.
Materials (Basel) ; 16(21)2023 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-37959642

RESUMEN

Groundwater contamination by trichloroethylene (TCE) presents a pressing environmental challenge with far-reaching consequences. Traditional remediation methods have shown limitations in effectively addressing TCE contamination. This study reviews the limitations of conventional remediation techniques and investigates the application of oxidant-based controlled-release materials, including encapsulated, loaded, and gel-based potassium permanganate since the year 2000. Additionally, it examines reductant controlled-release materials and electron donor-release materials such as tetrabutyl orthosilicate (TBOS) and polyhydroxybutyrate (PHB). The findings suggest that controlled-release materials offer a promising avenue for enhancing TCE degradation and promoting groundwater restoration. This study concludes by highlighting the future research directions and the potential of controlled-release materials in addressing TCE contamination challenges.

6.
Materials (Basel) ; 16(19)2023 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-37834540

RESUMEN

A novel prediction model for crack development of reinforced concrete (RC) piles with localized chloride corrosion in the marine environment is proposed. A discrete method is used to solve the corrosion pit radius model and a crack extension model is developed to investigate the initiation and extension of cracks. The maximum corrosion degree of the reinforced concrete pile is predicted according to the limit crack criterion, and finally, a sensitivity analysis is carried out on the important parameters of crack extension. The results show that the radius of the corrosion pit, the depth corrosion pit, and the cross-sectional area loss of reinforcement gradually increase as the corrosion level increases. The loss of the local reinforcement section at crack initiation increases with the increase in the ratio of concrete cover to initial diameter and increases with the increase in the pitting factor. The required pit depth for reinforcement cracking increases with the increase in the ratio of concrete cover thickness to diameter. The loss of the cross-sectional area of reinforcement and the radius of the corrosion pit increase with the increase in the initial diameter of reinforcement. Increasing the pitting factor can reduce the pit depth and make the crack width develop faster before reaching the limit crack width. Increasing the concrete cover thickness can provide an improvement in the propagation of cracks. A comparative analysis shows that the localized corrosion pattern is more in conformity with marine engineering practice.

7.
Materials (Basel) ; 15(17)2022 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-36079314

RESUMEN

TiH2-basd powder metallurgy (PM) is one of the effective ways to prepared high temperature titanium alloy. To study the thermomechanical behavior of near-α titanium alloy and proper design of hot forming, isothermal compression test of TiH2-based PM near-α type Ti-5.05Al-3.69Zr-1.96Sn-0.32Mo-0.29Si (Ti-1100) alloy was performed at temperatures of 1123-1323 K, strain rates of 0.01-1 s-1, and maximum deformation degree of 60%. The hot deformation characteristics of alloy were analyzed by strain hardening exponent (n), strain rate sensitivity (m), and processing map, along with microstructure observation. The flow stress revealed that the difference in softening/hardening behavior at temperature of 1273-1323 K and the strain rate of 1 s-1 compared to the lower deformation temperature and strain rate. The strain hardening exponents at temperatures of 1123 K are all negative under all strain rates, and the most severe flow softening with minimum value of n was observed at 1123 K and 1 s-1. The strain rate sensitives showed that the peak region with m value greater than 0.5 generally appeared in the high temperature range of 1273-1323 K, while strain rate sensitivity at low temperature behaved differently with strain rates. The processing map developed for strain of 0.6 exhibited high power dissipation efficiency at high temperatures of 1273-1323 K and a low strain rate of 0.01 s-1, due to microstructure evolution of ß phase. The decrease of strain rate at 1323 K resulted in the formation of globularization of α lamellae. The instability domain of flow behavior was identified in the temperature range of 1123-1173 K and at the strain rate higher than 0.01 s-1 reflecting the localized plastic flow and adiabatic shear banding, and inhomogenous microstructure. The variation of power dissipation energy (η) slope with strain demonstrated that the power dissipation mechanism during hot deformation has been changed from temperature-dependent to microstructure-dependent with the increase of temperature for the alloy deformed at 0.1 s-1. Eventually, the optimum processing range to deform the material is at 1273-1323 K and a strain rate range of 0.01-0.165 s-1 (lnε˙ = -4.6--1.8).

8.
Small ; 18(19): e2200073, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35257478

RESUMEN

Atomically dispersed metal catalysts often exhibit high catalytic performances, but the metal loading density must be kept low to avoid the formation of metal nanoparticles, making it difficult to improve the overall activity. Diverse strategies based on creating more anchoring sites (ASs) have been adopted to elevate the loading density. One problem of such traditional methods is that the single atoms always gather together before the saturation of all ASs. Here, a chemical scissors strategy is developed by selectively removing unwanted metallic materials after excessive loading. Different from traditional ways, the chemical scissors strategy places more emphasis on the accurate matching between the strength of etching agent and the bond energies of metal-metal/metal-substrate, thus enabling a higher loading up to 2.02 wt% even on bare substrate without any pre-treatment (the bare substrate without any pre-treatment generally only has a few ASs for single atom loading). It can be inferred that by combining with other traditional methods which can create more ASs, the loading could be further increased by saturating ASs. When used for CH3 OH generation via photocatalytic CO2 reduction, the as-made single-atom catalyst exhibits impressive catalytic activity of 597.8 ± 144.6 µmol h-1 g-1 and selectivity of 81.3 ± 3.8%.


Asunto(s)
Nanopartículas del Metal , Metales , Catálisis , Metales/química , Fenómenos Físicos
9.
Exp Ther Med ; 22(6): 1465, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34737805

RESUMEN

Cisplatin (DDP) resistance is one of the main causes of treatment failure in patients with colon cancer (CC). Autophagy is a key mechanism of resistance to chemotherapy. Since autophagy-related 7 (ATG7) has been reported to be involved in the regulation of autophagy and DDP resistance for lung and esophageal cancer, the present study aimed to explore the functions of microRNA (miR)-4486 in the autophagy-mediated DDP resistance of CC. The expression level of miR-4486 in HCT116, DDP-resistant HCT116 cells (HCT116/DDP), SW480 and DDP-resistant SW480 cells (SW480/DDP) was quantified by reverse transcription-quantitative PCR. Western blotting was utilized to analyze the expression of ATG7, autophagy-related proteins Beclin 1 and LC3-I/II, as well as apoptosis-related proteins Bcl-2, Bax and cleaved-caspase 3 in HCT116/DDP and SW480/DDP cells. The half maximal inhibitory concentration of DDP on all cell lines and the cell viability of HCT116/DDP and SW480/DDP cells were measured using Cell Counting Kit 8 assay. Luciferase assay was used to examine the potential targets of miR-4486 and ATG7. The effects of upregulating mimic miR-4486 expression on the apoptosis and autophagy of HCT116/DDP and SW480/DDP cells were determined by flow cytometry and electron microscopy, respectively. It was found that miR-4486 expression was significantly decreased in HCT116/DDP and SW480/DDP cells compared with that in HCT116 and SW480 cells. Overexpression of miR-4486 could increase the sensitivity of HCT116/DDP and SW480/DDP cells to DDP by reducing cell viability, promoting apoptosis and inhibiting autophagy through downregulating Beclin 1 expression and the LC3-II/LC3-I ratio. Additionally, ATG7 was identified to be a target gene of miR-4486, where ATG7 overexpression could partially reverse the effects of miR-4486 on cell viability and apoptosis by promoting the formation of autophagosomes. In conclusion, the present results demonstrated that miR-4486 could reverse DDP resistance in HCT116/DDP and SW480/DDP cells by targeting ATG7 to inhibit autophagy.

10.
Angew Chem Int Ed Engl ; 60(28): 15344-15347, 2021 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-33904226

RESUMEN

Cu-based electrocatalysts facilitate CO2 electrochemical reduction (CO2 ER) to produce multi-carbon products. However, the roles of Cu0 and Cu+ and the mechanistic understanding remain elusive. This paper describes the controllable construction of Cu0 -Cu+ sites derived from the well-dispersed cupric oxide particles supported on copper phyllosilicate lamella to enhance CO2 ER performance. 20 % Cu/CuSiO3 shows the superior CO2 ER performance with 51.8 % C2 H4 Faraday efficiency at -1.1 V vs reversible hydrogen electrode during the 6 hour test. In situ attenuated total reflection infrared spectra and density functional theory (DFT) calculations were employed to elucidate the reaction mechanism. The enhancement in CO2 ER activity is mainly attributed to the synergism of Cu0 -Cu+ pairs: Cu0 activates CO2 and facilitates the following electron transfers; Cu+ strengthens *CO adsorption to further boost C-C coupling. We provide a strategy to rationally design Cu-based catalysts with viable valence states to boost CO2 ER.

11.
Angew Chem Int Ed Engl ; 59(31): 12664-12668, 2020 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-32227608

RESUMEN

It is of great significance to reveal the detailed mechanism of neighboring effects between monomers, as they could not only affect the intermediate bonding but also change the reaction pathway. This paper describes the electronic effect between neighboring Zn/Co monomers effectively promoting CO2 electroreduction to CO. Zn and Co atoms coordinated on N doped carbon (ZnCoNC) show a CO faradaic efficiency of 93.2 % at -0.5 V versus RHE during a 30-hours test. Extended X-ray absorption fine structure measurements (EXAFS) indicated no direct metal-metal bonding and X-ray absorption near-edge structure (XANES) showed the electronic effect between Zn/Co monomers. In situ attenuated total reflection-infrared spectroscopy (ATR-IR) and density functional theory (DFT) calculations further revealed that the electronic effect between Zn/Co enhanced the *COOH intermediate bonding on Zn sites and thus promoted CO production. This work could act as a promising way to reveal the mechanism of neighboring monomers and to influence catalysis.

12.
ChemSusChem ; 13(23): 6353-6359, 2020 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-32175685

RESUMEN

The development of electrochemical CO2 conversion allows green carbon utilization. Formate and syngas are two typical products of electrochemical CO2 reduction, and the coproduction of these two products will maximize the energy efficiency of CO2 conversion. However, few works have successfully achieved the cogeneration of formate and syngas. This paper describes a novel strategy to maximize the efficiency of CO2 conversion through coproduction of formate and syngas on ultrasmall SnO2 nanodots (NDs) homogeneously anchored on carbon nanotubes (CNT#SnO2 NDs) electrodes. The CNT#SnO2 NDs not only decreased the adsorption energy of *OCHO but also reduced the adsorption energy difference of *COOH and *H. High energy efficiency toward formate and adjustable H2 /CO ratio were obtained over a broad potential window with long-term stability. In addition, CNT#SnO2 NDs and Ir foil were coupled together to construct an electrolyzer for electrochemical CO2 reduction reaction and oxygen evolution reaction (CO2 ERR-OER), which also produced formate and syngas with 24 h stability. A promising approach is presented for the electrochemical CO2 conversion in fuel production.

13.
Carbohydr Polym ; 236: 115999, 2020 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-32172833

RESUMEN

Cellulose nanofibers (CNFs) from kelp were prepared by cellulase treatment with lengths greater than 3 µm. CNFs were further oxidized by TEMPO-oxidized system, and the lengths of the oxidized CNFs (TEMPO-CNFs) were 0.6-1 µm. AFM and TEM images showed that intertwined CNFs fibers were divided into individual nanofibrils. The crystallinity of TEMPO-CNFs increased to 66.5 %. TGA analysis indicated that TEMPO-CNFs were more sensitive to temperature than cellulose and CNFs. FT-IR spectra revealed no changes in the basic cellulose structures of CNFs and TEMPO-CNFs. In the sunflower oil/water (20/80, v/v) model emulsions, the oil droplet sizes were less than 20 µm in CNFs emulsions, which became smaller in TEMPO-CNFs emulsions. Delamination was found in CNFs emulsions after three days of storage. Addition of NaCl increased the volumes of TEMPO-CNFs emulsions but enlarged the oil droplets sizes. TEMPO-CNFs emulsions had the largest volume with smallest and most homogeneous oil droplets at pH 3. TEMPO-CNFs emulsions showed good stability after storage for 30 days. Further, TEMPO-CNFs could also emulsify 50 % (v/v) of sunflower oil. All these results indicated that TEMPO-CNFs can be used in preparing Pickering emulsions.


Asunto(s)
Celulosa Oxidada/química , Emulsiones/química , Kelp/química , Laminaria/química , Nanofibras/química , Óxidos N-Cíclicos/química , Tamaño de la Partícula , Aceite de Girasol/química
14.
J Food Biochem ; 44(6): e13197, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32189350

RESUMEN

In this work, the cinnamaldehyde (CA) loaded nanoparticles were synthesized by directly cross-linking chitosan hydrochloride (CSH) and sulfobutyl ether-ß-cyclodextrin (SBE-ß-CD). The CA/SBE-ß-CD inclusion complex was firstly prepared, and its highest encapsulation efficiency (EE) was 86.34%. Field Emission Scanning Electron Microscope results indicated that the inclusion complex showed massive aggregates with a coarse and fluffy texture and irregular surface. Then, the inclusion complex interacted with CSH to form nanoparticles. The EE of CA in nanoparticles was improved. Atomic force microscopy showed the nanoparticles had regular and spherical morphology. Fourier transform infrared spectroscopy analysis demonstrated that CA was mainly encapsulated in the inner place of CSH/SBE-ß-CD nanoparticles (CSNs). The enhanced thermal stability of the nanoparticles was found in differential scanning calorimeter. X-ray diffraction implied that CA-CSNs existed in the amorphous state. CA-CSNs had excellent slow release property. Further, the bacteriostatic effect of CA-CSNs was much better than that of CA and CSNs. All the results indicated that CSNs can be used as a promising carrier to encapsulate CA. PRACTICAL APPLICATIONS: CA is an effective antimicrobial and generally recognized as Safe-GRAS. CA also exhibits many other bioactivities and has been commonly used for digestive, cardiovascular and immune system diseases. However, CA is easy to be oxidized and volatilized during storage for poor water solubility. The nanoencapsulations display the capacities of enhancing solubility of bioactive compounds, protecting them from degradation, and prolonging their residence. In this manuscript, CA loaded nanoparticles were investigated. The results suggested that the nanoencapsulation could benefit for improving water solubility and stability of CA. This strategy could be helpful for its application and development in food preservation.


Asunto(s)
Quitosano , Nanopartículas , beta-Ciclodextrinas , Acroleína/análogos & derivados , Éteres
15.
J Am Chem Soc ; 142(15): 6878-6883, 2020 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-32220209

RESUMEN

The grain boundary in copper-based electrocatalysts has been demonstrated to improve the selectivity of solar-driven electrochemical CO2 reduction toward multicarbon products. However, the approach to form grain boundaries in copper is still limited. This paper describes a controllable grain growth of copper electrodeposition via poly(vinylpyrrolidone) used as an additive. A grain-boundary-rich metallic copper could be obtained to convert CO2 into ethylene and ethanol with a high selectivity of 70% over a wide potential range. In situ attenuated total reflection surface-enhanced infrared absorption spectroscopy unveils that the existence of grain boundaries enhances the adsorption of the key intermediate (*CO) on the copper surface to boost the further CO2 reduction. When coupling with a commercially available Si solar cell, the device achieves a remarkable solar-to-C2-products conversion efficiency of 3.88% at a large current density of 52 mA·cm-2. This low-cost and efficient device is promising for large-scale application of solar-driven CO2 reduction.

16.
Angew Chem Int Ed Engl ; 58(41): 14549-14555, 2019 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-31418998

RESUMEN

The photocatalytic CO2 reduction reaction (CRR) represents a promising route for the clean utilization of stranded renewable resources, but poor selectivity resulting from the competing hydrogen evolution reaction (HER) in aqueous solution limits its practical applicability. In the present contribution a photocatalyst with hydrophobic surfaces was fabricated. It facilitates an efficient three-phase contact of CO2 (gas), H2 O (liquid), and catalyst (solid). Thus, concentrated CO2 molecules in the gas phase contact the catalyst surface directly, and can overcome the mass-transfer limitations of CO2 , inhibit the HER because of lowering proton contacts, and overall enhance the CRR. Even when loaded with platinum nanoparticles, one of the most efficient HER promotion cocatalysts, the three-phase photocatalyst maintains a selectivity of 87.9 %. Overall, three-phase photocatalysis provides a general and reliable method to enhance the competitiveness of the CRR.

17.
Artif Cells Nanomed Biotechnol ; 47(1): 1248-1255, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30945565

RESUMEN

Mitochondrial dysfunction is a major contributory factor for myocardial ischemia-reperfusion (I/R) injury. It has been reported that Pink1-Parkin-mediated mitochondrial autophagy could effectively remove damaged mitochondria and excess ROS to ensure the stability of intracellular mitochondria. The present study was designed to evaluate whether the polymerized porcine haemoglobin (pPolyHb), a novel type of haemoglobin oxygen carrier, has an effect on I/R injury via regulating the Pink1-Parkin mediated mitochondrial autophagy pathway in myocardial H9C2 cells. The results revealed that pPolyHb could effectively reduce apoptosis and improve the survival rates of H9C2 cells. In addition, Pink1 and Parkin levels gradually decreased with pPolyHb reoxygenation. The inhibition of mitochondrial autophagy through mitochondrial-division inhibitor-1(mdivi-1) resulted in a decrease in anti-apoptotic protein Bcl-2 and an increase in pro-apoptotic protein Bax and CytC. In conclusion, pPolyHb has a protective effect on myocardial ischemia-reperfusion injury by regulating moderate mitochondrial autophagy.


Asunto(s)
Autofagia/efectos de los fármacos , Hemoglobinas/farmacología , Mitocondrias/efectos de los fármacos , Daño por Reperfusión Miocárdica/patología , Miocitos Cardíacos/efectos de los fármacos , Proteínas Quinasas/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Animales , Apoptosis/efectos de los fármacos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Citocromos c/metabolismo , Citoprotección/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Hemoglobinas/química , Humanos , L-Lactato Deshidrogenasa/metabolismo , Mitocondrias/patología , Daño por Reperfusión Miocárdica/prevención & control , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Oxígeno/metabolismo , Multimerización de Proteína , Estructura Cuaternaria de Proteína , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Porcinos , Proteína X Asociada a bcl-2/metabolismo
18.
J Am Chem Soc ; 141(12): 4791-4794, 2019 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-30862159

RESUMEN

Electrocatalytic reduction of carbon dioxide (CO2ER) to reusable carbon resources is a significant step to balance the carbon cycle. This Communication describes a seed-mediated growth method to synthesize ultrathin Pd-Au alloy nanoshells with controllable alloying degree on Pd nanocubes. Specifically, Pd@Pd3Au7 nanocrystals (NCs) show superior CO2ER performance, with a 94% CO faraday efficiency (FE) at -0.5 V vs reversible hydrogen electrode and approaching 100% CO FE from -0.6 to -0.9 V. The enhancement primarily originates from ensemble and ligand effects, i.e., appropriately proportional Pd-Au sites and electronic back-donation from Au to Pd. In situ attenuated total reflection infrared spectra and density functional theory calculations clarify the reaction mechanism. This work may offer a general strategy for the synthesis of bimetallic NCs to explore the structure-activity relationship in catalytic reactions.

19.
Food Chem ; 272: 643-652, 2019 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-30309593

RESUMEN

This study investigated the effects of a novel edible coating combining fish gelatin with curcumin/ß-cyclodextrin (CUR/ßCD) emulsion on the quality of grass carp fillets (GCFs) during storage at 4 °C. For all samples, the quality parameters, including weight loss, pH, total volatile basic nitrogen (TVB-N), peroxide value (PV), thiobarbituric acid (TBA) value, SDS-PAGE, free amino acids (FAA), microbiological (total viable counts (TVC), Pseudomonas counts, yeasts and molds, and H2S-producing bacteria), color and sensorial characteristics, were tested periodically. The coatings containing CUR/ßCD emulsions exhibited better preservative effects than gelatin/ßCD coating. Therefore, fish gelatin coating enriched with CUR/ßCD emulsion can be used as an effective way to maintain the quality of GCF and extend its shelf life during storage at 4 °C.


Asunto(s)
Emulsiones/química , Almacenamiento de Alimentos/métodos , Gelatina/química , Sustancias Protectoras/química , Alimentos Marinos/análisis , Aminoácidos/análisis , Animales , Carpas , Curcumina/química , Concentración de Iones de Hidrógeno , Pseudomonas/aislamiento & purificación , Alimentos Marinos/microbiología , Temperatura , Tiobarbitúricos/análisis , beta-Ciclodextrinas/química
20.
Chem Soc Rev ; 48(7): 1874-1907, 2019 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-30525133

RESUMEN

Photocatalysis is a promising route to convert solar energy into chemical energy directly, providing an alternative solution to environment and natural resource problems. Theoretically, all photocatalytic reactions are driven by charge carriers whose behavior can be divided into charge generation, separation, migration and surface reactions. Efficiencies of charge utilization in every step determine the overall performance of photocatalysis. Yolk-shell (YS) structures can provide an ideal platform for the efficient utilization of charge carriers. Typically, a YS structure is constructed from a hollow shell and an inner core, which can enhance light scattering in the hollow space and provide a large surface to create sufficient active sites, both of which can significantly improve the efficacy of charge utilization. Additionally, many strategies can be adopted to modify the YS structure for further enhancement of charge behaviors in every step. Existing reviews about YS structures mainly concentrate on the universality of the application of YSs, while the strategies to improve photocatalytic performance based on YSs have not been elaborately illustrated. This review describes the classification, synthesis, formation mechanism of YS structures and the rational regulation of the behaviors of photogenerated charge carriers, aiming at their effective utilization based on YS structures in heterogeneous photocatalytic reactions.

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