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1.
Small ; : e2309431, 2024 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-38402425

RESUMEN

Clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein 9 (Cas9) is a promising gene editing tool to treat diseases at the genetic level. Nonetheless, the challenge of the safe and efficient delivery of CRISPR/Cas9 to host cells constrains its clinical applicability. In the current study, a facile, redox-responsive CRISPR/Cas9-Ribonucleoprotein (RNP) delivery system by combining iron-coordinated aggregation with liposomes (Fe-RNP@L) is reported. The Fe-RNP is formed by the coordination of Fe3+ with amino and carboxyl groups of Cas9, which modifies the lipophilicity and surface charge of RNP and alters cellular uptake from primary endocytosis to endocytosis and cholesterol-dependent membrane fusion. RNP can be rapidly and reversibly released from Fe-RNP in response to glutathione without loss of structural integrity and enzymatic activity. In addition, iron coordination also improves the stability of RNP and substantially mitigates cytotoxicity. This construct enabled highly efficient cytoplasmic/nuclear delivery (≈90%) and gene-editing efficiency (≈70%) even at low concentrations. The high payload content, high editing efficiency, good stability, low immunogenicity, and ease of production and storage, highlight its potential for diverse genome editing and clinical applications.

2.
Nanotechnology ; 35(32)2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38697049

RESUMEN

Perovskite quantum dots (QDs) and organic materials have great research potential in the field of optoelectronic devices. In this paper, MEH-PPV/CsPbBr3heterojunction photodetectors (PDs) are prepared by spin coating method based on the good photoelectric properties of CsPbBr3perovskite QDs and MEH-PPV. The MEH-PPV/CsPbBr3heterojunction improves the energy level arrangement, and CsPbBr3QDs can passivate the surface defects of MEH-PPV films to achieve effective charge separation and transfer, thus inhibiting the dark current and improving the photoelectric performance of the device. Under 532 nm laser irradiation, the responsivity (R) of MEH-PPV/CsPbBr3heterojunction PD is 11.98 A W-1, the specific detectivity (D*) is 6.98 × 1011Jones, and the response time is 15/16 ms. This work provides experience for the study of perovskite QDs and organic materials heterojunction optoelectronic devices.

3.
Molecules ; 29(13)2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38999048

RESUMEN

Self-powered photoelectrochemical (PEC) ultraviolet photodetectors (UVPDs) are promising for next-generation energy-saving and highly integrated optoelectronic systems. Constructing a heterojunction is an effective strategy to increase the photodetection performance of PEC UVPDs because it can promote the separation and transfer of photogenerated carriers. However, both crystal defects and lattice mismatch lead to deteriorated device performance. Here, we introduce a structural regulation strategy to prepare TiO2 anatase-rutile heterophase homojunctions (A-R HHs) with oxygen vacancies (OVs) photoanodes through an in situ topological transformation of titanium metal-organic framework (Ti-MOF) by pyrolysis treatment. The cooperative interaction between A-R HHs and OVs suppresses carrier recombination and accelerates carrier transport, thereby significantly enhancing the photodetection performance of PEC UVPDs. The obtained device realizes a high on/off ratio of 10,752, a remarkable responsivity of 24.15 mA W-1, an impressive detectivity of 3.28 × 1011 Jones, and excellent cycling stability. More importantly, under 365 nm light illumination, a high-resolution image of "HUST" (the abbreviation of Harbin University of Science and Technology) was obtained perfectly, confirming the excellent optical imaging capability of the device. This research not only presents an advanced methodology for constructing TiO2-based PEC UVPDs, but also provides strategic guidance for enhancing their performance and practical applications.

4.
Curr Ther Res Clin Exp ; 100: 100743, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38617895

RESUMEN

Objective: This study aims to analyze a severe adverse reaction of pulmonary fibrosis induced by dronedarone hydrochloride tablets, and to provide a reference for clinical rational medication through drug precautions. Methods: A case of pulmonary fibrosis induced by dronedarone hydrochloride tablets, along with related literature was retrospectively analyzed. Results: Patients over 65 years old with a history of exposure to amiodarone may increase the incidence of pulmonary toxicity induced by dronedarone, and dronedarone should not be selected as a substitute treatment drug for patients with amiodarone-induced pulmonary toxicity. Conclusions: It is recommended that clinicians monitor the diffusion capacity of carbon monoxide and lung ventilation function of patients before and after using dronedarone for treatment. For patients with a history of amiodarone exposure, intermittent monitoring of chest X-rays and lung function is necessary. If lung function decreases, dronedarone should be immediately discontinued.

5.
Nanotechnology ; 34(22)2023 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-36854175

RESUMEN

Ga2O3is a good candidate for deep ultraviolet photodetectors due to its wide-bandgap, good chemical, and thermal stability. Ga2O3-based photoelectrochemical (PEC) photodetectors attract increasing attention due to the simple fabrication and self-powered capability, but the corresponding photoresponse is still inferior. In this paper, the oxygen vacancy (Vo) engineering towardsα-Ga2O3was proposed to obtain high-performance PEC photodetectors. Theα-Ga2O3nanorods were synthesized by a simple hydrothermal method with an annealing process. The final samples were named as Ga2O3-400, Ga2O3-500, and Ga2O3-600 for annealing at 400 ℃, 500 ℃, and 600 ℃, respectively. Different annealing temperatures lead to different Voconcentrations in theα-Ga2O3nanorods. The responsivity is 101.5 mA W-1for Ga2O3-400 nanorod film-based PEC photodetectors under 254 nm illumination, which is 1.4 and 4.0 times higher than those of Ga2O3-500 and Ga2O3-600 nanorod film-based PEC photodetectors, respectively. The photoresponse ofα-Ga2O3nanorod film-based PEC photodetectors strongly depends on the Voconcentration and high Voconcentration accelerates the interfacial carrier transfer of Ga2O3-400, enhancing the photoresponse of Ga2O3-400 nanorod film-based PEC photodetectors. Furthermore, theα-Ga2O3nanorod film-based PEC photodetectors have good multicycle, long-term stability, and repeatability. Our result shows thatα-Ga2O3nanorods have promising applications in deep UV photodetectors.

6.
Ecotoxicol Environ Saf ; 255: 114796, 2023 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-36948006

RESUMEN

Plastic particle pollution poses an emerging threat to ecological and human health. Laboratory animal studies have illustrated that nano-sized plastics can accumulate in the testis and cause testosterone deficiency and spermatogenic impairment. In this study, TM3 mouse Leydig cells were in vitro exposed to polystyrene nanoparticles (PS-NPs, size 20 nm) at dosages of 50, 100 and 150 µg/mL to investigate their cytotoxicity. Our results demonstrated that PS-NPs can be internalized into TM3 Leydig cells and led to a concentration-dependent decline in cell viability. Furthermore, PS-NPs stimulation amplified ROS generation and initiated cellular oxidative stress and apoptosis. Moreover, PS-NPs treatment affected the mitochondrial DNA copy number and collapsed the mitochondrial membrane potential, accompanied by a disrupted energy metabolism. The cells exposed to PS-NPs also displayed a down-regulated expression of steroidogenesis-related genes StAR, P450scc and 17ß-HSD, along with a decrease in testosterone secretion. In addition, treatment with PS-NPs destructed plasma membrane integrity, as presented by increase in lactate dehydrogenase release and depolarization of cell membrane potential. In summary, these data indicated that exposure to PS-NPs in vitro produced cytotoxic effect on Leydig cells by inducing oxidative injury, mitochondrial impairment, apoptosis, and cytomembrane destruction. Our results provide new insights into male reproductive toxicity caused by NPs.


Asunto(s)
Células Intersticiales del Testículo , Nanopartículas , Ratones , Animales , Masculino , Humanos , Células Intersticiales del Testículo/metabolismo , Microplásticos/metabolismo , Poliestirenos/toxicidad , Plásticos/metabolismo , Nanopartículas/toxicidad , Nanopartículas/metabolismo , Testosterona/metabolismo
7.
J Am Chem Soc ; 144(33): 15193-15202, 2022 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-35926139

RESUMEN

Data carriers using spin waves in spintronic and magnonic logic devices offer operation at low power consumption and free of Joule heating yet requiring noncollinear spin structures of small sizes. Heterometallic rings can provide such an opportunity due to the controlled spin-wave transmission within such a confined space. Here, we present a series of {ScnGdn} (n = 4, 6, 8) heterometallic rings, which are the first Sc-Ln clusters to date, with tunable magnetic interactions for spin-wave excitations. By means of time- and temperature-dependent spin dynamics simulations, we are able to predict distinct spin-wave excitations at finite temperatures for Sc4Gd4, Sc6Gd6, and Sc8Gd8. Such a new model is previously unexploited, especially due to the interplay of antiferromagnetic exchange, dipole-dipole interaction, and ring topology at low temperatures, rendering the importance of the latter to spin-wave excitations.

8.
Langmuir ; 34(30): 8857-8865, 2018 07 31.
Artículo en Inglés | MEDLINE | ID: mdl-29979601

RESUMEN

Natural cellulose has been used as a coating to stabilize oil-in-water (o/w) emulsions by exploiting the amphiphilic character of the cellulose chains molecularly dissolved in the ionic liquid 1-ethyl-3-methylimidazolium acetate. Its cellulose coating exhibits a continuous amorphous structure which differs significantly from the cellulose particle stabilization used in Pickering emulsions. The structure of these cellulose-coated o/w emulsion particles, in particular the cellulose coating shell characteristics (thickness, porosity, and composition), is studied by using a combination of direct imaging methods such as cryogenic electron microscopy and fluorescence microscopy with small-angle neutron scattering measurements. This work suggests a unique multicompartment structure of the emulsion particles: an oil core, surrounded by an inner shell composed of a porous cellulose gel, encapsulated by a dense outer cellulose shell, a few nanometers in thickness. The thickness of the inner cellulose shell varies significantly. The nanoscale emulsion droplets exhibit a thickness of 10 ± 3 nm, whereas the larger micron-sized droplets exhibit a thicker inner cellulose shell of 500-750 nm. It is also inferred that the cellulose shells contain water rather than oil.

9.
Soft Matter ; 13(46): 8756-8765, 2017 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-29130090

RESUMEN

We investigate the transition of the phase separation kinetics from a complete to an arrested liquid-liquid phase separation (LLPS) in mixtures of bovine γ-globulin with polyethylene glycol (PEG). The solutions feature LLPS with upper critical solution temperature phase behavior. At higher PEG concentrations or low temperatures, non-equilibrium, gel-like states are found. The kinetics is followed during off-critical quenches by ultra-small angle X-ray scattering (USAXS) and very-small angle neutron scattering (VSANS). For shallow quenches a kinetics consistent with classical spinodal decomposition is found, with the characteristic length (ξ) growing with time as ξ ∼ t1/3. For deep quenches, ξ grows only very slowly with a growth exponent smaller than 0.05 during the observation time, indicating an arrested phase separation. For intermediate quench depths, a novel growth kinetics featuring a three-stage coarsening is observed, with an initial classical coarsening, a subsequent slowdown of the growth, and a later resumption of coarsening approaching again ξ ∼ t1/3. Samples featuring the three-stage coarsening undergo a temporarily arrested state. We hypothesize that, while intermittent coarsening and collapse might contribute to the temporary nature of the arrested state, migration-coalescence of the minority liquid phase through the majority glassy phase may be the main mechanism underlying this kinetics, which is also consistent with earlier simulation results.

10.
Soft Matter ; 12(46): 9334-9341, 2016 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-27830221

RESUMEN

We study the kinetics of the liquid-liquid phase separation (LLPS) and its arrest in protein solutions exhibiting a lower critical solution temperature (LCST) phase behavior using the combination of ultra-small angle X-ray scattering (USAXS) and very-small angle neutron scattering (VSANS). We employ a previously established model system consisting of bovine serum albumin (BSA) solutions with YCl3. We follow the phase transition from sub-second to 104 s upon an off-critical temperature jump. After a temperature jump, the USAXS profiles exhibit a peak that grows in intensity and shifts to lower q values with time. Below 45 °C, the characteristic length scale (ξ) obtained from this scattering peak increases with time with a power of about 1/3 for different sample compositions. This is in good agreement with the theoretical prediction for the intermediate stage of spinodal decomposition where the growth is driven by interface tension. Above 45 °C, ξ follows initially the 1/3 power law growth, then undergoes a significant slowdown, and an arrested state is reached below the denaturation temperature of the protein. This growth kinetics may indicate that the final composition of the protein-rich phase is located close to the high density branch of the LLPS binodal when a kinetically arrested state is reached.


Asunto(s)
Proteínas/química , Dispersión del Ángulo Pequeño , Cinética , Transición de Fase , Soluciones , Temperatura
11.
Surgery ; 175(4): 1140-1146, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38290878

RESUMEN

BACKGROUND: Hand-sewn anastomosis and stapled anastomosis are the 2 main types of gastrojejunal anastomotic methods in pancreaticoduodenectomy. There is ongoing debate regarding the most effective anastomotic method for reducing delayed gastric emptying after pancreaticoduodenectomy. This study aims to identify factors that influence delayed gastric emptying after pancreaticoduodenectomy and assess the impact of different anastomotic methods on delayed gastric emptying. METHODS: The study included 1,077 patients who had undergone either hand-sewn anastomosis (n = 734) or stapled anastomosis (n = 343) during pancreaticoduodenectomy between December 2016 and November 2021 at our department. We retrospectively analyzed the clinical data, and a 1:1 propensity score matching was performed to balance confounding variables. RESULTS: After propensity score matching, 320 patients were included in each group. Compared with the stapled anastomosis group, the hand-sewn anastomosis group had a significantly lower incidence of delayed gastric emptying (28 [8.8%] vs 55 [17.2%], P = .001) and upper gastrointestinal tract bleeding (6 [1.9%] vs 17 [5.3%], P = .02). Additionally, the hand-sewn anastomosis group had a significantly reduced postoperative length of stay and lower hospitalization expenses. However, the hand-sewn anastomosis group had a significantly longer operative time, which was consistent with the analysis before propensity score matching. Logistic regression analysis showed that stapled anastomosis, intra-abdominal infection, and clinically relevant postoperative pancreatic fistula were independent prognostic factors for delayed gastric emptying. CONCLUSION: Hand-sewn anastomosis was associated with a lower incidence rate of clinically relevant delayed gastric emptying after pancreaticoduodenectomy. Stapled anastomosis, intra-abdominal infection, and clinically relevant postoperative pancreatic fistula could increase the incidence of postoperative clinically relevant delayed gastric emptying. Hand-sewn anastomosis should be considered by surgeons to reduce the occurrence of postoperative delayed gastric emptying and improve patient outcomes.


Asunto(s)
Gastroparesia , Infecciones Intraabdominales , Humanos , Pancreaticoduodenectomía/efectos adversos , Pancreaticoduodenectomía/métodos , Estudios Retrospectivos , Gastroparesia/epidemiología , Gastroparesia/etiología , Gastroparesia/prevención & control , Fístula Pancreática/epidemiología , Fístula Pancreática/etiología , Fístula Pancreática/prevención & control , Anastomosis Quirúrgica/efectos adversos , Anastomosis Quirúrgica/métodos , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/prevención & control , Infecciones Intraabdominales/complicaciones , Vaciamiento Gástrico , Resultado del Tratamiento
12.
Adv Sci (Weinh) ; 11(16): e2304940, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38417114

RESUMEN

Inadequate ß-cell mass and insulin secretion are essential for the development of type 2 diabetes (T2D). TNF-α-induced protein 8-like 1 (Tipe1) plays a crucial role in multiple diseases, however, a specific role in T2D pathogenesis remains largely unexplored. Herein, Tipe1 as a key regulator in T2D, contributing to the maintenance of ß cell homeostasis is identified. The results show that the ß-cell-specific knockout of Tipe1 (termed Ins2-Tipe1BKO) aggravated diabetic phenotypes in db/db mice or in mice with high-fat diet-induced diabetes. Notably, Tipe1 improves ß cell mass and function, a process that depends on Gαs, the α subunit of the G-stimulating protein. Mechanistically, Tipe1 inhibited the K48-linked ubiquitination degradation of Gαs by recruiting the deubiquitinase USP5. Consequently, Gαs or cAMP agonists almost completely restored the dysfunction of ß cells observed in Ins2-Tipe1BKO mice. The findings characterize Tipe1 as a regulator of ß cell function through the Gαs/cAMP pathway, suggesting that Tipe1 may emerge as a novel target for T2D intervention.


Asunto(s)
Proliferación Celular , Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Ratones Noqueados , Transducción de Señal , Animales , Ratones , Células Secretoras de Insulina/metabolismo , Transducción de Señal/genética , Proliferación Celular/genética , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Péptidos y Proteínas de Señalización Intracelular/genética , Secreción de Insulina/genética , AMP Cíclico/metabolismo , Modelos Animales de Enfermedad , Masculino , Humanos , Ratones Endogámicos C57BL , Insulina/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/genética
13.
Nat Commun ; 15(1): 5636, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38965232

RESUMEN

Natural antimicrobial peptides (AMPs) and enzymes (AMEs) are promising non-antibiotic candidates against antimicrobial resistance but suffer from low efficiency and poor stability. Here, we develop peptide nanozymes which mimic the mode of action of AMPs and AMEs through de novo design and peptide assembly. Through modelling a minimal building block of IHIHICI is proposed by combining critical amino acids in AMPs and AMEs and hydrophobic isoleucine to conduct assembly. Experimental validations reveal that IHIHICI assemble into helical ß-sheet nanotubes with acetate modulation and perform phospholipase C-like and peroxidase-like activities with Ni coordination, demonstrating high thermostability and resistance to enzymatic degradation. The assembled nanotubes demonstrate cascade antifungal actions including outer mannan docking, wall disruption, lipid peroxidation and subsequent ferroptotic death, synergistically killing >90% Candida albicans within 10 min on disinfection pad. These findings demonstrate an effective de novo design strategy for developing materials with multi-antimicrobial mode of actions.


Asunto(s)
Antifúngicos , Candida albicans , Antifúngicos/farmacología , Antifúngicos/química , Candida albicans/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Nanotubos/química , Péptidos Antimicrobianos/farmacología , Péptidos Antimicrobianos/química , Peroxidación de Lípido/efectos de los fármacos , Péptidos/farmacología , Péptidos/química
14.
Anal Chim Acta ; 1250: 340970, 2023 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-36898811

RESUMEN

Immobilized enzymes outperform free enzymes in many properties and are widely used in environmental monitoring, engineering applications, food and medical fields. Based on the developed immobilization techniques, the search for immobilization with wider applicability, lower cost and more stable enzyme properties is of significant importance. In this study, we reported a molecular imprinting strategy for immobilizing peptide mimics of DhHP-6 on mesoporous materials. The DhHP-6 molecularly imprinted polymer (MIP) showed much higher adsorption capacity than raw mesoporous silica toward DhHP-6. The DhHP-6 peptide mimics was immobilized on the surface of mesoporous silica for the fast detection of phenolic compounds, a widely spread pollutant with highly toxic and difficult in degradation. Immobilized enzyme of DhHP-6-MIP exhibited higher peroxidase activity, better stability, and recyclability than free peptide. Notably, DhHP-6-MIP showed excellent linearity for the detection of the two phenols with detection limits of 0.28 µM and 0.25 µM, respectively. In combination with the spectral analysis and PCA method, DhHP-6-MIP provided better discrimination between the six phenolic compounds (phenol, catechol, resorcinol, hydroquinone, 2-chlorophenol, 2, 4-dichlorophenol). Our study showed that immobilization of peptide mimics by the molecular imprinting strategy using mesoporous silica as carriers was a simple and effective approach. The DhHP-6-MIP has great potentiality for the monitoring and degradation of environmental pollutants.


Asunto(s)
Impresión Molecular , Nanopartículas , Polímeros/química , Fenoles/química , Impresión Molecular/métodos , Polímeros Impresos Molecularmente , Péptidos , Dióxido de Silicio/química , Adsorción
15.
Front Endocrinol (Lausanne) ; 14: 1114463, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36891048

RESUMEN

As emerging organic contaminants, per- and polyfluoroalkyl substances (PFASs) have aroused worldwide concern due to their environmental persistence, ubiquitous presence, bioaccumulation, and potential toxicity. It has been demonstrated that PFASs can accumulate in human body and cause multiple adverse health outcomes. Notably, PFASs have been detected in the semen of human, posing a potential hazard to male fecundity. This article reviews the evidence about the toxic effects of exposure to PFASs on male reproduction, focusing on the sperm quality. Epidemiological studies showed that PFASs, such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), were adversely associated with the semen parameters in humans, including sperm count, morphology and motility. Experimental results also confirmed that PFAS exposure led to testicular and epididymal damage, therefore impairing spermatogenesis and sperm quality. The mechanisms of reproductive toxicity of PFASs may be involved in blood-testosterone barrier destruction, testicular apoptosis, testosterone synthesis disorder, and membrane lipid composition alteration, oxidative stress and Ca2+ influx in sperm. In conclusion, this review highlighted the potential threat of exposure to PFASs to human spermatozoa.


Asunto(s)
Contaminantes Ambientales , Fluorocarburos , Masculino , Humanos , Semen , Contaminantes Ambientales/toxicidad , Fluorocarburos/toxicidad , Espermatozoides , Testosterona
16.
Nat Commun ; 14(1): 5808, 2023 09 19.
Artículo en Inglés | MEDLINE | ID: mdl-37726302

RESUMEN

Amyloid-like assembly is not only associated with pathological events, but also leads to the development of novel nanomaterials with unique properties. Herein, using Fmoc diphenylalanine peptide (Fmoc-F-F) as a minimalistic model, we found that histidine can modulate the assembly behavior of Fmoc-F-F and induce enzyme-like catalysis. Specifically, the presence of histidine rearranges the ß structure of Fmoc-F-F to assemble nanofilaments, resulting in the formation of active site to mimic peroxidase-like activity that catalyzes ROS generation. A similar catalytic property is also observed in Aß assembled filaments, which is correlated with the spatial proximity between intermolecular histidine and F-F. Notably, the assembled Aß filaments are able to induce cellular ROS elevation and damage neuron cells, providing an insight into the pathological relationship between Aß aggregation and Alzheimer's disease. These findings highlight the potential of histidine as a modulator in amyloid-like assembly of peptide nanomaterials exerting enzyme-like catalysis.


Asunto(s)
Histidina , Nanoestructuras , Especies Reactivas de Oxígeno , Proteínas Amiloidogénicas , Péptidos
17.
Materials (Basel) ; 15(3)2022 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-35160681

RESUMEN

Thermal interface materials with high thermal conductivity and low hardness are crucial to the heat dissipation of high-power electronics. In this study, a high magnetic field was used to align the milled carbon fibers (CFs, 150 µm) in silicone rubber matrix to fabricate thermal interface materials with an ordered and discontinuous structure. The relationship among the magnetic field density, the alignment degree of CFs, and the properties of the resulting composites was explored by experimental study and theoretical analysis. The results showed higher alignment degree and enhanced thermal conductivity of composites under increased magnetic flux density within a certain curing time. When the magnetic flux density increased to 9 T, the CFs showed perfect alignment and the composite showed a high thermal conductivity of 11.76 W/(m·K) with only 20 vol% CF loading, owing to the ordered structure. Meanwhile, due to the low filler loading and discontinuous structure, a low hardness of 60~70 (shore 00) was also realized. Their thermal management performance was further confirmed in a test system, revealing promising applications for magnetic aligned CF-rubber composites in thermal interface materials.

18.
Spectrochim Acta A Mol Biomol Spectrosc ; 281: 121606, 2022 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-35839694

RESUMEN

2-Methylimidazole (MIM) is a classic organic ligand that shows excellent thermal stability and chemical robustness and is widely used in ZIFs. Recently, transformations of MOFs have been realized by using metals or ligands. In this study, we propose a new strategy-adjusting MIM by extending the alkyl chain length -to change the properties of related MOFs. Furthermore, we used copper as the metal core to replace zinc to mimic the active sites of laccases (electron transfer between copper and imidazole ring). As a result, the nanostructures transformed from nanoleaves to nanovesicles, which changed the Cu(II)/Cu(I) ratio from 3.7 to 1.7, as well as the lattice constant (decreased the diffraction angle) and enzyme-like activity (inhibition). In addition, we revealed that superoxidase anions were the main factors responsible for its laccase-like activity. We applied it to detect and discriminate phenolics. Laccase-mimicking activity was best at pH 7.0. When compared to protein laccase, the Cu-MeIm nanozyme had a greater Vmax at the same mass concentration. It was used to identify and distinguish phenolics. In the presence of Cu-MeIm nanozymes, the linear range is 0.1-2 mM and the detection limit of 2,4-DCP is 0.034 mM.


Asunto(s)
Lacasa , Nanoestructuras , Cobre/química , Lacasa/química , Lacasa/metabolismo , Ligandos , Compuestos Orgánicos , Fenoles
19.
J Nutr Biochem ; 110: 109144, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36057413

RESUMEN

Lycopene (LYC) has been regarded as a nutraceutical that has powerful antioxidant and hepatoprotective bioactivities. In the present study, we aimed to investigate the beneficial effects of LYC on hepatic insulin signal transduction under oxidative stress conditions and the possible involvement of FGF21 and mitochondria pathways. Two-month-old CD-1 mice were treated by intraperitoneal injection of D-galactose (D-gal) 150 mg/kg/day for 8 weeks and received 0.03% LYC (w/w, mixed into diet). The results showed that LYC increased the expression of FGF21, alleviated mitochondrial dysfunction and improved hepatic insulin signal transduction in D-gal-treated mice. Furthermore, knockdown of FGF21 by small interfering RNA notably suppressed mitochondrial function and blunted LYC-stimulated insulin signal transduction in H2O2-treated HepG2 cells. Moreover, suppressed mitochondrial function via oligomycin also inhibited insulin signal transduction, indicating that LYC supplementation ameliorated oxidative stress-induced hepatic dysfunction of insulin signal transduction by up-regulating FGF21 and enhancing mitochondrial function.


Asunto(s)
Peróxido de Hidrógeno , Insulina , Animales , Ratones , Licopeno/farmacología , Peróxido de Hidrógeno/metabolismo , Insulina/metabolismo , Estrés Oxidativo , Mitocondrias/metabolismo , Transducción de Señal
20.
RSC Adv ; 12(51): 32898-32902, 2022 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-36425211

RESUMEN

Nanozyme is a material with enzyme-like catalytic activity, which has been widely used in environmental, antibacterial, and other fields of research. However, there are few reports on the toxicity of nanozymes. In this work, nanozymes co-assembled from sodium N-lauroyl sarcosinate (Ls) and Cu ions possess a Cu(i)-Cu(ii) electron transfer system similar to that of natural laccases. Reaction kinetic studies show that the catalyst follows a typical Michaelis-Menten model. Cu-N-lauroyl sarcosinate nanozyme (Cu-Ls NZ) possess excellent laccase-like activity to oxidize a variety of phenol-containing substrates, such as phenol, 4-iodophenol, and 2,4,5-trichlorophenol. To evaluate the toxicity of the material, the nematode C. elegans was exposed to various concentrations of Cu-Ls NZ. Effects on physiological levels were determined. The results showed that high doses of Cu-Ls NZ increased the amount of reactive oxygen species (ROS), decreased the locomotor activity of nematodes, and inhibited their larval growth.

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