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1.
Nature ; 601(7894): 573-578, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-35082415

RESUMEN

Owing to rapid development in their efficiency1 and stability2, perovskite solar cells are at the forefront of emerging photovoltaic technologies. State-of-the-art cells exhibit voltage losses3-8 approaching the theoretical minimum and near-unity internal quantum efficiency9-13, but conversion efficiencies are limited by the fill factor (<83%, below the Shockley-Queisser limit of approximately 90%). This limitation results from non-ideal charge transport between the perovskite absorber and the cell's electrodes5,8,13-16. Reducing the electrical series resistance of charge transport layers is therefore crucial for improving efficiency. Here we introduce a reverse-doping process to fabricate nitrogen-doped titanium oxide electron transport layers with outstanding charge transport performance. By incorporating this charge transport material into perovskite solar cells, we demonstrate 1-cm2 cells with fill factors of >86%, and an average fill factor of 85.3%. We also report a certified steady-state efficiency of 22.6% for a 1-cm2 cell (23.33% ± 0.58% from a reverse current-voltage scan).

2.
Environ Toxicol ; 39(4): 2077-2085, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38100242

RESUMEN

Colorectal cancer (CRC) exhibits highly metastatic potential even in the early stages of tumor progression. Gallic acid (GA), a common phenolic compound in plants, is known to possess potent antioxidant and anticancer activities, thereby inducing cell death or cell cycle arrest. However, whether GA reduces the invasiveness of CRC cells without inducing cell death remains unclear. Herein, we aimed to investigate the antimetastatic activity of low-dose GA on CRC cells and determine its underlying mechanism. Cell viability and tumorigenicity were analyzed by MTS, cell adhesion, and colony formation assay. Invasiveness was demonstrated using migration and invasion assays. Changes in protein phosphorylation and expression were assessed by Western blot. The involvement of microRNAs was validated by microarray analysis and anti-miR antagonist. Our findings showed that lower dose of GA (≤100 µM) did not affect cell viability but reduced the capabilities of colony formation, cell adhesion, and invasiveness in CRC cells. Cellularly, GA downregulated the cellular level of integrin αV/ß3, talin-1, and tensin and diminished the phosphorylated FAK, paxillin, Src, and AKT in DLD-1 cells. Microarray results revealed that GA increased miR-1247-3p expression, and pretreatment of anti-miR antagonist against miR-1247-3p restored the GA-reduced integrin αV/ß3 and the GA-inhibited paxillin activation in DLD-1 cells. Consistently, the in vivo xenograft model showed that GA administration inhibited tumor growth and liver metastasis derived from DLD-1 cells. Collectively, our findings indicated that GA inhibited the metastatic capabilities of CRC cells, which may result from the suppression of integrin/FAK axis mediated by miR1247-3p.


Asunto(s)
Neoplasias Colorrectales , MicroARNs , Humanos , Paxillin/genética , Paxillin/metabolismo , Integrinas/genética , Integrinas/metabolismo , Ácido Gálico/farmacología , Antagomirs , Integrina alfaV/metabolismo , Línea Celular Tumoral , Proliferación Celular , MicroARNs/genética , MicroARNs/metabolismo , Neoplasias Colorrectales/metabolismo , Movimiento Celular , Regulación Neoplásica de la Expresión Génica
3.
Int J Med Sci ; 19(10): 1557-1566, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36185329

RESUMEN

Extra-proliferation and increased migration of vascular smooth cells con-tribute to the formation of atherosclerosis. Ras small G proteins play a critical role in the prolif-eration and migration of a wide range of cells. Mulberry, an economic fruit in Asia, exhibits anti-inflammation, anti-migration, and anti-oxidant properties. The mechanisms of action of mulberry extracts on K-Ras small G protein-induced proliferation and migration of vascular smooth muscle cell have not been extensively investigated. In this study, we explored the effects of mulberry polyphenol extracts (MPE) on the proliferation and migration of K-Ras-overexpressing A7r5 smooth muscle cells. The overexpression of K-Ras enhanced the ex-pression and activity of matrix metalloproteinase (MMP)-2, promoted vascular endothelial growth factor (VEGF) production, and eventually triggered the migration of A7r5 cells. Treatment with MPE attenuated K-Ras-induced phenomenon. In addition, MPE blocked K-Ras-induced actin fibril stress. MPE dose-dependently diminished K-Ras-induced Rho A, Rac1, CDC42, and phosphorylated focal adhesion kinase (FAK) expression. MPE elevated Rho B ex-pression. Phosphorylated AKT and glycogen synthase kinase (GSK) induced by K-Ras were also repressed by MPE treatment. MPE enhanced the interaction of IκB with NFκB. MPE restored the G0/G1 population and p21 and p27 expressions, which were repressed by K-Ras. Finally, MPE triggered the degradation of K-Ras by ubiquitination. MPE inhibited the migration and proliferation of vascular smooth cell through K-Ras-induced pathways and eventually pre-vented atherosclerosis.


Asunto(s)
Aterosclerosis , Proteínas de Unión al GTP Monoméricas , Morus , Actinas/metabolismo , Antioxidantes/farmacología , Aterosclerosis/tratamiento farmacológico , Aterosclerosis/genética , Aterosclerosis/metabolismo , Movimiento Celular/genética , Proliferación Celular/genética , Células Cultivadas , Regulación hacia Abajo , Proteína-Tirosina Quinasas de Adhesión Focal/metabolismo , Frutas/metabolismo , Glucógeno Sintasa Quinasas/metabolismo , Humanos , Proteínas de Unión al GTP Monoméricas/metabolismo , Proteínas de Unión al GTP Monoméricas/farmacología , Músculo Liso Vascular , Miocitos del Músculo Liso , Polifenoles/metabolismo , Polifenoles/farmacología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal , Factor A de Crecimiento Endotelial Vascular/metabolismo
4.
Protein Expr Purif ; 187: 105950, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34363980

RESUMEN

Interleukin-17A (IL-17A) produced by Th17 cells, contributes to the pathogenesis of various autoimmune diseases by stimulating the release of cytokines and chemokines and its regulation. Anti-IL-17A antibody which blocks the function of IL-17A has been proved to be an effective treatment of autoimmune disease. The aim of our study was to generate a potential humanized anti-IL-17A therapeutic monoclonal antibody (mAb) through a comprehensive panel of in vitro and in vivo biological activity studies, as well as physicochemical characterization. HZD37-5, a humanized monoclonal antibody specifically recognizing N78 loci of IL-17A, binds to human and rhesus monkeys, blocks IL-17 induced signal transduction and the release of IL-6, IL-8, CXCL-1 and G-GSF. In an in vivo efficacy mouse model, HZD37-5 significantly inhibited human IL-17A induced-keratinocyte chemoattractant (KC) secretion in a dose-dependent manner. The pharmacokinetics (PK) study result of HZD37-5 in rhesus monkeys indicated that HZD37-5 had favorable PK characteristics with limited distribution (78.0-78.8 ml/kg), slow elimination (5.00-6.45 ml/day/kg), long half-life (9.1-10.7 days) and high bioavailability (103%) following a single IV or SC dose at 1.5 mg/kg. These findings provided a comprehensive preclinical characterization of HZD37-5 and supported that it may be developed as a potential therapeutic for the treatment of autoimmune diseases, including psoriasis, psoriatic arthritis, axial spondyloarthritis, etc.


Asunto(s)
Anticuerpos Monoclonales Humanizados/farmacocinética , Enfermedades Autoinmunes/tratamiento farmacológico , Interleucina-17/inmunología , Animales , Anticuerpos Monoclonales Humanizados/inmunología , Quimiocina CXCL1/inmunología , Factores Quimiotácticos/inmunología , Relación Dosis-Respuesta a Droga , Humanos , Interleucina-6/inmunología , Interleucina-8/inmunología , Queratinocitos/inmunología , Macaca mulatta , Ratones , Conejos , Transducción de Señal
5.
Small ; 16(49): e2005022, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33201580

RESUMEN

Dimensional engineering of perovskite solar cells has attracted significant research attention recently because of the potential to improve both device performance and stability. Here, a novel 2D passivation scheme for 3D perovskite solar cells is demonstrated using a mixed cation composition of 2D perovskite based on two different isomers of butylammonium iodide. The dual-cation 2D perovskite outperforms its single cation 2D counterparts in surface passivation quality, resulting in devices with an impressive open-circuit voltage of 1.21 V for a perovskite composition with an optical bandgap of ≈1.6 eV, and a champion efficiency of 23.27%. Using a combination of surface elemental analysis and valence electron spectra decomposition, it is shown that an in situ interaction between the 2D perovskite precursor and the 3D active layer results in surface intermixing of 3D and 2D perovskite phases, providing an effective combination of defect passivation and enhanced charge transfer, despite the semi-insulating nature of the 2D perovskite phase. The demonstration of the synergistic interaction of multiple organic spacer cations in a 2D passivation layer offers new opportunities for further enhancement of device performance with mixed dimensional perovskite solar cells.

6.
J Emerg Med ; 56(2): 210-212, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30420310

RESUMEN

BACKGROUND: The Heimlich maneuver is a simple and universal resuscitative procedure that is performed to relieve foreign-body airway obstruction. We present a case of silent Stanford type A aortic dissection, a rarely reported complication of the Heimlich maneuver. CASE REPORT: A 67-year-old male presented to the emergency department with left-sided hemiplegia shortly after receiving a Heimlich maneuver. Acute ischemic stroke was suspected, and the thrombolytic protocol was initiated. Fortunately, Stanford type A aortic dissection was diagnosed before the thrombolytic therapy was initiated. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Aortic dissection can develop after the Heimlich maneuver. For patients who develop a neurologic deficit after the Heimlich maneuver, vascular dissection should be considered as a possible cause.


Asunto(s)
Disección Aórtica/etiología , Maniobra de Heimlich/efectos adversos , Anciano , Obstrucción de las Vías Aéreas/terapia , Disección Aórtica/diagnóstico , Disección Aórtica/diagnóstico por imagen , Angiografía por Tomografía Computarizada/métodos , Humanos , Masculino , Resucitación/métodos , Resucitación/normas
7.
Small ; 14(26): e1800181, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29806184

RESUMEN

The solvent-engineering method is widely used to fabricate top-performing perovskite solar cells, which, however, usually exhibit inferior reproducibility. Herein, a two-stage annealing (TSA) strategy is demonstrated for processing of perovskite films, namely, annealing the intermediate phase at 60 °C for the first stage then at 100 °C for the second stage. Compared to conventional direct annealing temperature (DHA) at 100 °C, using this strategy, MAPbI3 films become more controllable, leading to superior film uniformity and device reproducibility with the champion device efficiency reaching 19.8%. More specifically, the coefficient of variation of efficiency for 49 cells is reduced to 5.9%, compared to 9.8% for that using DHA. The TSA process is carefully studied using Fourier transform infrared spectroscopy, X-ray diffraction, and UV-vis absorption spectroscopy. It is found that in comparison with DHA the formation of hydrogen bonding and crystallization of perovskite are much slower and can be better controlled when using TSA. The improvements in film uniformity and device reproducibility are attributed to: 1) controllable MAPbI3 crystal growth stemming from the progressive formation of hydrogen bonding between methylammonium and halide; 2) suppression of intermediate phase film dewetting, which is believed to be due to its decreased mobility at the initial low-temperature annealing stage.

8.
Rapid Commun Mass Spectrom ; 31(4): 381-388, 2017 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-27933719

RESUMEN

RATIONALE: In order to determine the degree of cross-linking on the surface and its variations in a nanometer-scale depth of organic materials, we developed an approach based on time-of-flight secondary ion mass spectrometry (TOF-SIMS), which provides rich chemical information in the form of fragment ions. TOF-SIMS is extremely surface-sensitive and capable of depth profiling with the use of a sputter ion beam to remove controllable amounts of substance. METHODS: Poly(methyl methacrylate) (PMMA) films spin-coated on a Si substrate were cross-linked using a recently developed, surface sensitive, hyperthermal hydrogen projectile bombardment technique. The ion intensity ratio between two ubiquitous hydrocarbon ions, C6 H- and C4 H- , detected in TOF-SIMS, denoted as ρ, was used to assess the degree of cross-linking of the PMMA films. The cross-linking depth of the PMMA films was revealed by depth profiling ρ into the polymer films using a C60+ sputter beam. RESULTS: The control PMMA film spin-coated on a Si substrate was characterized by ρ = 32% on its surface when using a 25 keV Bi3+ primary ion beam. This parameter on the PMMA films subjected to HHIC treatment for 10, 100 and 500 s increased to 45%, 56% and 65%, respectively. The depth profiles of ρ obtained using a 10 keV C60+ ion beam resembled an exponential decay, from which the cross-linking depth was estimated to be 3, 15 and 39 nm, respectively, for the three cross-linked PMMA films. CONCLUSIONS: We demonstrated that the ion intensity ratio of C6 H- to C4 H- detected in TOF-SIMS provides a unique and simple means to assess the degree of cross-linking of the surface of PMMA films cross-linked by the surface sensitive hyperthermal hydrogen projectile bombardment technique. With a C60+ sputter beam, we were able to depth profile the PMMA films and determine cross-linking depths of the cross-linked polymer films at nanometer resolutions. Copyright © 2017 John Wiley & Sons, Ltd.

9.
Phys Chem Chem Phys ; 19(4): 3094-3103, 2017 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-28079207

RESUMEN

The issue of hysteresis in perovskite solar cells has now been convincingly linked to the presence of mobile ions within the perovskite layer. Here we test the limits of the ionic theory by attempting to account for a number of exotic characterization results using a detailed numerical device model that incorporates ionic charge accumulation at the perovskite interfaces. Our experimental observations include a temporary enhancement in open-circuit voltage following prolonged periods of negative bias, dramatically S-shaped current-voltage sweeps, decreased current extraction following positive biasing or "inverted hysteresis", and non-monotonic transient behaviours in the dark and the light. Each one of these phenomena can be reproduced and ultimately explained by our models, providing further evidence for the ionic theory of hysteresis as well as valuable physical insight into the factors that coincide to bring these phenomena about. In particular we find that both interfacial recombination and carrier injection from the selective contacts are heavily affected by ionic accumulation, and are essential to explaining the non-monotonic voltage transients and S-shaped J-V curves. Inverted hysteresis is attributed to the occurrence of "positive" ionic accumulation, which may also be responsible for enhancing the stabilized open-circuit voltage in some perovskite cells.

10.
Tumour Biol ; 2016 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-27709553

RESUMEN

Infantile hemangioma (IH) is one of the most common vascular tumors of childhood. Long noncoding RNAs (lncRNAs) play a critical role in angiogenesis, but their involvement in hemangioma remains unknown. This study aimed to assess the expression profiles of lncRNAs in IH and adjacent normal tissue samples, exploring the biological functions of lncRNAs as well as their involvement in IH pathogenesis. The lncRNA expression profiles were determined by lncRNA microarrays. A total of 1259 and 857 lncRNAs were upregulated and downregulated in IH, respectively, at a fold change cutoff of 2.0 (p < 0.05); in addition, 1469 and 1184 messenger RNAs (mRNAs) were upregulated and downregulated, respectively (fold change cutoff of 2.0; p < 0.05). A total of 292 differentially expressed mRNAs were targeted by the lncRNAs with altered expression in hemangioma, including 228 and 64 upregulated and downregulated, respectively (cutoff of 2.0, p < 0.05). Gene ontology (GO) analyses revealed several angiogenesis-related pathways. An lncRNA-mRNA co-expression network for differentially expressed lncRNAs revealed significant associations of the lncRNAs MEG3, MEG8, FENDRR, and Linc00152 with their related mRNAs. The validation results of nine differentially expressed lncRNAs (MALAT1, MEG3, MEG8, p29066, p33867, FENDRR, Linc00152, p44557_v4, p8683) as well as two mRNAs (FOXF1, EGFL7) indicated that the microarray data correlated well with the QPCR results. Interestingly, MALAT1 knockdown induced apoptosis and S-phase cell cycle arrest in human umbilical vein endothelial cells (HUVECs). Overall, this study revealed the lncRNA expression profile of IH and that lncRNAs likely regulate several genes with important roles in angiogenesis.

12.
Int J Biol Macromol ; 268(Pt 2): 131721, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38649079

RESUMEN

Interferon (IFN) alpha/beta receptor 1 (IFNAR1) is indispensable for antiviral responses and the immune regulation. Dysregulation of the IFNAR1-mediaetd signaling pathways leads to deleterious autoimmune diseases such as systemic lupus erythematosus (SLE). QX006N, a humanized therapeutic monoclonal antibody, specifically targets human IFNAR1 and is in the clinical trial phase for treating SLE, but the molecular mechanism underlying the QX006N-mediated recognition of IFNAR1 remains unclear. Here, we report the high neutralization activities of QX006N against IFNAR1-mediated signal transduction. Meanwhile, we determine the structures of the fragment antigen-binding domain (Fab) of QX006N (QX006N-Fab) and QX006N-Fab in complex with the subdomains 1-3 of IFNAR1 (IFNAR1-SD123) at 2.87 Å and 2.68 Å resolutions, respectively. In the structure of the QX006N-Fab/IFNAR1-SD123 complex, QX006N-Fab only recognizes the SD3 subdomain of IFNAR1 by the hydrophobic, hydrogen-bonding and electrostatic interactions. Compared with the structure of the IFN/IFNAR1/IFNAR2 complex, the binding of QX006N-Fab to IFNAR1-SD3 blocks its association with IFN due to steric hindrance, which inhibits the IFN/IFNAR1/IFNAR2 complex formation for signal transduction. The results of this study provide the structural evidence for the specific targeting of IFNAR1 by the therapeutic antibody QX006N and pave the way for the rational design of antibody drugs to combat IFNAR1-related autoimmune diseases.


Asunto(s)
Anticuerpos Monoclonales Humanizados , Lupus Eritematoso Sistémico , Receptor de Interferón alfa y beta , Receptor de Interferón alfa y beta/metabolismo , Receptor de Interferón alfa y beta/química , Lupus Eritematoso Sistémico/tratamiento farmacológico , Lupus Eritematoso Sistémico/inmunología , Humanos , Anticuerpos Monoclonales Humanizados/química , Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticuerpos Monoclonales Humanizados/farmacología , Unión Proteica , Modelos Moleculares , Fragmentos Fab de Inmunoglobulinas/química , Fragmentos Fab de Inmunoglobulinas/inmunología , Transducción de Señal/efectos de los fármacos , Relación Estructura-Actividad
13.
Science ; 385(6708): 554-560, 2024 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-39088618

RESUMEN

Wide-bandgap (WBG) absorbers in tandem configurations suffer from poor crystallinity and weak texture, which leads to severe mixed halide-cation ion migration and phase segregation during practical operation. We control WBG film growth insensitive to compositions by nucleating the 3C phase before any formation of bromine-rich aggregates and 2H phases. The resultant WBG absorbers show improved crystallinity and strong texture with suppressed nonradiative recombination and enhanced resistance to various aging stresses. Perovskite/silicon tandem solar cells achieve power conversion efficiencies of 29.4% (28.8% assessed by a third party) in a 25-square centimeter active area and 32.5% in a 1-square centimeter active area. These solar cells retained 98.3 and 90% of the original efficiency after 1301 and 800 hours of operation at 25° and 50°C, respectively, at the maximum power point (AM 1.5G illumination, full spectrum, 1-sun) when encapsulated.

14.
Nanotechnology ; 24(4): 045402, 2013 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-23299200

RESUMEN

Here we report the fabrication of a novel photovoltaic device based on CuS nanotubes (CuSNTs) and indium tin oxide (ITO) Schottky junctions. Large-quantity synthesis of CuSNTs was accomplished via a solution-based sacrificial template method under moderate conditions, while ITO Schottky contacts were fabricated via micro-fabrication and pulsed laser deposition (PLD). Upon light illumination, CuSNTs-ITO Schottky junctions exhibited pronounced photovoltaic behavior, giving rise to a power conversion efficiency of 1.17% on a conventional SiO(2)/Si substrate. Furthermore, by utilizing PET as the substrate, transparent and flexible CuSNTs-ITO solar cells were constructed and showed performance close to their device counterparts on a rigid substrate. Notably, it was found that the flexible devices were robust against tensile strain and could stand a bending angle up to ∼95°. To enhance the light absorption of the devices, an Ag mirror layer was deposited on the rear side of the PET substrate so as to allow multiple reflection and absorption of the incident light. As a result, the flexible devices showed a substantial performance improvement, yielding an efficiency of ∼2%. Our results demonstrate that low-cost and environmentally friendly CuSNTs-ITO solar cells are promising candidates for new-generation photovoltaic devices.


Asunto(s)
Cobre/química , Suministros de Energía Eléctrica , Lentes , Nanotubos/química , Plata/química , Energía Solar , Compuestos de Estaño/química , Cobre/efectos de la radiación , Módulo de Elasticidad , Electrodos , Diseño de Equipo , Análisis de Falla de Equipo , Nanotubos/ultraestructura , Tamaño de la Partícula , Semiconductores , Plata/efectos de la radiación , Compuestos de Estaño/efectos de la radiación
15.
Acta Cardiol Sin ; 29(4): 366-9, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27122731

RESUMEN

UNLABELLED: Infective endocarditis in hypertrophic obstructive cardiomyopathy is rare. Management of this disease is challenging due to the unique features of dynamic pressure gradient over the left ventricular outflow tract and its unpredictable interaction with the management of sepsis. The added complexity of infective endocarditis further complicates an already difficult situation. A 72-year-old man with hypertrophic obstructive cardiomyopathy presented with acute stroke, fever, and Staphylococcus aureus bacteremia. Infective endocarditis of the aortic valve was confirmed. Despite treatment with antibiotics and aortic valve replacement, the patient had recurrent bacteremia and developed a periannular abscess and a subaortic-right atrial fistula, with a resulting fatal outcome. KEY WORDS: Aortic valve replacement; Endocarditis; Hypertrophic obstructive cardiomyopathy; Subaortic-right atrial fistula.

16.
Adv Mater ; 35(17): e2211257, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36753745

RESUMEN

Metal halide perovskites are promising as next-generation photovoltaic materials, but stability issues are still a huge obstacle to their commercialization. Here, the formation and evolution of cracks in perovskite films during thermal cycling, which affect their mechanical stability, are investigated. Compressive strain is employed to suppress cracks and delamination by in situ formed polymers with low elastic modulus during crystal growth. The resultant devices pass the thermal-cycling qualification (IEC61215:2016), retaining 95% of the initial power conversion efficiency (PCE) and compressive strain after 230 cycles. Meanwhile, the p-i-n devices deliver PCEs of 23.91% (0.0805 cm2 ) and 23.27% (1 cm2 ). The findings shed light on strain engineering with respect to their evolution, which enables mechanically stable perovskite solar cells.

17.
J Am Chem Soc ; 134(36): 14869-76, 2012 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-22856890

RESUMEN

A three terminal molecular memory device was monitored with in situ Raman spectroscopy during bias-induced switching between two metastable states having different conductivity. The device structure is similar to that of a polythiophene field effect transistor, but ethylviologen perchlorate was added to provide a redox counter-reaction to accompany polythiophene redox reactions. The conductivity of the polythiophene layer was reversibly switched between high and low conductance states with a "write/erase" (W/E) bias, while a separate readout circuit monitored the polymer conductance. Raman spectroscopy revealed reversible polythiophene oxidation to its polaron form accompanied by a one-electron viologen reduction. "Write", "read", and "erase" operations were repeatable, with only minor degradation of response after 200 W/E cycles. The devices exhibited switching immediately after fabrication and did not require an "electroforming" step required in many types of memory devices. Spatially resolved Raman spectroscopy revealed polaron formation throughout the polymer layer, even away from the electrodes in the channel and drain regions, indicating that thiophene oxidation "propagates" by growth of the conducting polaron form away from the source electrode. The results definitively demonstrate concurrent redox reactions of both polythiophene and viologen in solid-state devices and correlate such reactions with device conductivity. The mechanism deduced from spectroscopic and electronic monitoring should guide significant improvements in memory performance.


Asunto(s)
Polímeros/química , Tiofenos/química , Viológenos/química , Estructura Molecular , Oxidación-Reducción , Espectrometría Raman , Factores de Tiempo
18.
Plant Cell Rep ; 31(1): 121-31, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21932029

RESUMEN

A resveratrol synthase gene was cloned from the peanut plant (Arachis hypogaea) by RT-PCR and was transformed into purple sweet potato (Ipomoea batatas) by Agrobacterium-mediated transformation. Stem sections were infected with bacterial solution of OD(600) = 0.4 for 20 min and then cocultured for 2 days. Infected explants were cultured on MS media containing 50 mg/l kanamycin, 0.02 mg/l NAA and 1 mg/l 6-BA for bud induction or containing 75 mg/l kanamycin, 1.0 mg/l NAA and 0.1 mg/l 6-BA for root formation. The bud and root induction rates were 37.5 and 25.0%, respectively. 105 regenerated plants were obtained, with 11 positive plants by PCR and Southern blotting analyses. A high level of resveratrol glucoside (340 µg/g dry weight), but no resveratrol, was detected in the transformed plants by HPLC. This study also provides a stable genetic transformation and plant regeneration method for metabolic modification of purple sweet potato.


Asunto(s)
Aciltransferasas/genética , Arachis/genética , Ipomoea batatas/genética , Aciltransferasas/metabolismo , Agrobacterium/genética , Clonación Molecular , Medios de Cultivo/química , Regulación Enzimológica de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Kanamicina/farmacología , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/genética , Raíces de Plantas/metabolismo , Plantas Modificadas Genéticamente/genética , Resveratrol , Análisis de Secuencia , Estilbenos/análisis , Estilbenos/metabolismo , Transformación Genética
19.
Nutrients ; 14(22)2022 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-36432495

RESUMEN

Mulberry leaf (Morus alba L.) is used as a traditional medicine and potential health food to treat various metabolic diseases, such as hypertension, diabetes, and hyperlipidemia. However, we sought the mechanisms by which functional components of mulberry leaves mediate diabetic steatohepatitis. We applied an in vitro model of HepG2 cells induced by glucolipotoxicity and evaluated the effects of MLE and its major components nCGA, Crp, and CGA. The results showed that MLE and nCGA reduced liver fat accumulation by inhibiting SREBP-1/FASN, SREBP-2/HMG-CoAR, and activating PPARα/CPT-1. Additionally, MLE and nCGA decreased inflammatory responses associated with NF-κB, TNF-α, and IL-6 to alleviate steatohepatitis. Furthermore, we showed that MLE and nCGA exerted anti-glucolipotoxicity effects by downregulating miR-34a, thus activating SIRT1/AMPK signaling, and subsequently suppressing hepatic lipid accumulation.


Asunto(s)
Hígado Graso , MicroARNs , Morus , Ácido Clorogénico/farmacología , Ácido Clorogénico/metabolismo , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/genética , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/metabolismo , Extractos Vegetales/farmacología , Extractos Vegetales/metabolismo , Hojas de la Planta/metabolismo , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Hígado Graso/metabolismo , Lípidos
20.
Nutrients ; 14(15)2022 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-35893859

RESUMEN

Mulberry leaf (Morus alba L.) has been used as a health food and in traditional medicine to treat several metabolic diseases, including diabetes, hypertension, and hyperlipidemia. However, the mechanism by which mulberry leaf and its functional components mediate atherosclerosis remains unclear. This study aimed to determine the effect of mulberry leaf extract (MLE) and its major component, neochlorogenic acid (nCGA), on the proliferation and migration of rat aortic vascular smooth muscle cells (VSMCs, A7r5 cell line) under diabetic cultured conditions (oleic acid and high glucose, OH). Our findings showed that MLE and nCGA significantly inhibited cell proliferation and migration in A7r5 cells as determined by a scratch wound assay and a Transwell assay. Furthermore, we observed MLE and nCGA inhibited cell proliferation and migration, such as reducing the phosphoinositide 3-kinases (PI3K)/protein kinase B (Akt), focal adhesion kinase (FAK), and small GTPase proteins using Western blot analysis. In conclusion, we confirmed the anti-atherosclerotic effects of MLE and nCGA in reducing vascular smooth muscle cell (VSMC) migration and proliferation under diabetic cultured conditions via inhibition of FAK/small GTPase proteins, PI3K/Akt, and Ras-related signaling.


Asunto(s)
Aterosclerosis , Proteínas de Unión al GTP Monoméricas , Morus , Animales , Aterosclerosis/metabolismo , Movimiento Celular , Proliferación Celular , Células Cultivadas , Ácido Clorogénico/análogos & derivados , Proteína-Tirosina Quinasas de Adhesión Focal/metabolismo , Proteínas de Unión al GTP Monoméricas/metabolismo , Músculo Liso Vascular , Miocitos del Músculo Liso , Estrés Oxidativo , Fosfatidilinositol 3-Quinasas/metabolismo , Extractos Vegetales/metabolismo , Extractos Vegetales/farmacología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ácido Quínico/análogos & derivados , Ratas , Transducción de Señal
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