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1.
Nanomaterials (Basel) ; 14(11)2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38869533

RESUMEN

In this study, a KrF excimer laser with a high-absorption coefficient in metal oxide films and a wavelength of 248 nm was selected for the post-processing of a film and metal oxide thin film transistor (MOTFT). Due to the poor negative bias illumination stress (NBIS) stability of indium gallium zinc oxide thin film transistor (IGZO-TFT) devices, terbium-doped Tb:In2O3 material was selected as the target of this study. The XPS test revealed the presence of both Tb3+ and Tb4+ ions in the Tb:In2O3 film. It was hypothesized that the peak of the laser thermal effect was reduced and the action time was prolonged by the f-f jump of Tb3+ ions and the C-T jump of Tb4+ ions during the laser treatment. Studies related to the treatment of Tb:In2O3 films with different laser energy densities have been carried out. It is shown that as the laser energy density increases, the film density increases, the thickness decreases, the carrier concentration increases, and the optical band gap widens. Terbium has a low electronegativity (1.1 eV) and a high Tb-O dissociation energy (707 kJ/mol), which brings about a large lattice distortion. The Tb:In2O3 films did not show significant crystallization even under laser energy density treatment of up to 250 mJ/cm2. Compared with pure In2O3-TFT, the doping of Tb ions effectively reduces the off-state current (1.16 × 10-11 A vs. 1.66 × 10-12 A), improves the switching current ratio (1.63 × 106 vs. 1.34 × 107) and improves the NBIS stability (ΔVON = -10.4 V vs. 6.4 V) and positive bias illumination stress (PBIS) stability (ΔVON = 8 V vs. 1.6 V).

2.
Nanomaterials (Basel) ; 11(11)2021 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-34835811

RESUMEN

Silver nanowire (AgNW) conductive film fabricated by solution processing was investigated as an alternative to indium tin oxide (ITO) in flexible transparent electrodes. In this paper, we studied a facile and effective method by electrodepositing Al2O3 on the surface of AgNWs. As a result, flexible transparent electrodes with improved stability could be obtained by electrodepositing Al2O3. It was found that, as the annealing temperature rises, the Al2O3 coating layer can be transformed from Al2O3·H2O into a denser amorphous state at 150 °C. By studying the increase of electrodeposition temperature, it was observed that the transmittance of the AgNW-Al2O3 composite films first rose to the maximum at 70 °C and then decreased. With the increase of the electrodeposition time, the figure of merit (FoM) of the composite films increased and reached the maximum when the time was 40 s. Through optimizing the experimental parameters, a high-stability AgNW flexible transparent electrode using polyimide (PI) as a substrate was prepared without sacrificing optical and electrical performance by electrodepositing at -1.1 V and 70 °C for 40 s with 0.1 mol/L Al(NO3)3 as the electrolyte, which can withstand a high temperature of 250 °C or 250,000 bending cycles with a bending radius of 4 mm.

3.
Sci Rep ; 6: 21014, 2016 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-26880221

RESUMEN

It has been more than a decade since the thermal conductivity of vertically aligned carbon nanotube (VACNT) arrays was reported possible to exceed that of the best thermal greases or phase change materials by an order of magnitude. Despite tremendous prospects as a thermal interface material (TIM), results were discouraging for practical applications. The primary reason is the large thermal contact resistance between the CNT tips and the heat sink. Here we report a simultaneous sevenfold increase in in-plane thermal conductivity and a fourfold reduction in the thermal contact resistance at the flexible CNT-SiO2 coated heat sink interface by coupling the CNTs with orderly physical overlapping along the horizontal direction through an engineering approach (shear pressing). The removal of empty space rapidly increases the density of transport channels, and the replacement of the fine CNT tips with their cylindrical surface insures intimate contact at CNT-SiO2 interface. Our results suggest horizontally aligned CNT arrays exhibit remarkably enhanced in-plane thermal conductivity and reduced out-of-plane thermal conductivity and thermal contact resistance. This novel structure makes CNT film promising for applications in chip-level heat dissipation. Besides TIM, it also provides for a solution to anisotropic heat spreader which is significant for eliminating hot spots.

4.
J Am Coll Cardiol ; 56(25): 2084-9, 2010 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-21144968

RESUMEN

OBJECTIVES: We compared the safety and efficacy of the XIENCE V (Abbott Vascular, Santa Clara, California) everolimus-eluting stent (EES) with the TAXUS Express (Boston Scientific, Natick, Massachusetts) paclitaxel-eluting stent (PES) among the large cohort of randomized diabetic patients enrolled in the SPIRIT IV (Clinical Evaluation of the XIENCE V Everolimus Eluting Coronary Stent System) trial. BACKGROUND: Diabetes mellitus remains a significant predictor of adverse clinical outcomes after percutaneous coronary intervention with drug-eluting stents, and the comparative outcomes of different drug-eluting stents in diabetic patients remains ill-defined. METHODS: In the SPIRIT IV trial, 3,687 patients with up to 3 de novo native coronary artery lesions were prospectively randomized 2:1 to receive EES or PES. Randomization was stratified by the presence of diabetes and lesion complexity. The primary end point was the occurrence of target lesion failure (TLF) (cardiac death, target-vessel myocardial infarction, or ischemia-driven target lesion revascularization) at 1 year. Clinical outcomes were evaluated in randomized diabetic (n = 1,185 [786 EES; 399 PES]) and nondiabetic patients (n = 2,498 [1,669 EES; 829 PES]). RESULTS: The EES compared with PES reduced TLF in nondiabetic patients (3.1% vs. 6.7%, p < 0.0001), with significant reductions in myocardial infarction, stent thrombosis, and target lesion revascularization. In contrast, no difference in TLF (6.4% vs. 6.9%, respectively, p = 0.80) or any of its components was present among diabetic patients, regardless of insulin use. A significant interaction between the presence of diabetes and stent type on TLF (p(interaction) = 0.02) was observed. CONCLUSIONS: In the SPIRIT IV randomized trial, EES compared with PES provided similar clinical outcomes in diabetic patients and superior clinical outcomes in nondiabetic patients at 1 year. (SPIRIT IV Clinical Trial: Clinical Evaluation of the XIENCE V Everolimus Eluting Coronary Stent System in the Treatment of Subjects With de Novo Native Coronary Artery Lesions; NCT00307047).


Asunto(s)
Angioplastia Coronaria con Balón/instrumentación , Enfermedad de la Arteria Coronaria/terapia , Angiopatías Diabéticas/terapia , Stents Liberadores de Fármacos , Inmunosupresores/administración & dosificación , Paclitaxel/administración & dosificación , Sirolimus/análogos & derivados , Anciano , Enfermedad de la Arteria Coronaria/complicaciones , Everolimus , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Sirolimus/administración & dosificación , Insuficiencia del Tratamiento
5.
ChemMedChem ; 4(1): 88-99, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19006142

RESUMEN

Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are part of the preferred treatment regimens for individuals infected with HIV. These NNRTI-based regimens are efficacious, but the most popular NNRTIs have a low genetic barrier to resistance and have been associated with adverse events. There is therefore still a need for efficacious antiviral medicines that facilitate patient adherence and allow durable suppression of viral replication. As part of an extensive program targeted toward the discovery of NNRTIs that have favorable pharmacokinetic properties, good potency against NNRTI-resistant viruses, and a high genetic barrier to drug resistance, we focused on the optimization of a series of diaryl ether NNRTIs. In the course of this effort, we employed molecular modeling to design a new set of NNRTIs that that are active against wild-type HIV and key NNRTI-resistant mutant viruses. The structure-activity relationships observed in this series of compounds provide insight into the structural features required for NNRTIs that inhibit the replication of a wide range of mutant viruses. Selected compounds have promising pharmacokinetic profiles.


Asunto(s)
Fármacos Anti-VIH/química , Transcriptasa Inversa del VIH/química , Éteres Fenílicos/química , Éteres Fenílicos/farmacología , Inhibidores de la Transcriptasa Inversa/química , Animales , Fármacos Anti-VIH/farmacocinética , Fármacos Anti-VIH/farmacología , Simulación por Computador , Perros , Diseño de Fármacos , Farmacorresistencia Viral/genética , VIH/genética , Transcriptasa Inversa del VIH/antagonistas & inhibidores , Concentración 50 Inhibidora , Modelos Moleculares , Mutación , Éteres Fenílicos/farmacocinética , Ratas , Inhibidores de la Transcriptasa Inversa/farmacocinética , Inhibidores de la Transcriptasa Inversa/farmacología , Relación Estructura-Actividad
6.
J Med Chem ; 51(23): 7449-58, 2008 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-19007201

RESUMEN

Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are recommended components of preferred combination antiretroviral therapies used for the treatment of HIV. These regimens are extremely effective in suppressing virus replication. Structure-based optimization of diaryl ether inhibitors led to the discovery of a new series of pyrazolo[3,4-c]pyridazine NNRTIs that bind the reverse transcriptase enzyme of human immunodeficiency virus-1 (HIV-RT) in an expanded volume relative to most other inhibitors in this class.The binding mode maintains the beta13 and beta14 strands bearing Pro236 in a position similar to that in the unliganded reverse transcriptase structure, and the distribution of interactions creates the opportunity for substantial resilience to single point mutations. Several pyrazolopyridazine NNRTIs were found to be highly effective against wild-type and NNRTI-resistant viral strains in cell culture.


Asunto(s)
Diseño de Fármacos , Transcriptasa Inversa del VIH/antagonistas & inhibidores , Pirazoles/farmacología , Inhibidores de la Transcriptasa Inversa/farmacología , Animales , Fármacos Anti-VIH/síntesis química , Fármacos Anti-VIH/química , Fármacos Anti-VIH/farmacología , Sitios de Unión , Línea Celular Transformada , Cristalografía por Rayos X , Perros , Transcriptasa Inversa del VIH/metabolismo , VIH-1/efectos de los fármacos , VIH-1/enzimología , Haplorrinos , Humanos , Enlace de Hidrógeno , Pruebas de Sensibilidad Microbiana , Modelos Moleculares , Estructura Molecular , Pirazoles/síntesis química , Pirazoles/química , Ratas , Inhibidores de la Transcriptasa Inversa/síntesis química , Inhibidores de la Transcriptasa Inversa/química , Estereoisomerismo , Relación Estructura-Actividad
7.
Mutat Res ; 579(1-2): 133-48, 2005 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-16054658

RESUMEN

Pro-fs is a human immunodeficiency virus type 1 (HIV-l)-encoded putative selenoprotein, predicted by a theoretical analysis of the viral genome; it is potentially expressed by a -1 frameshift from the protease coding region. Pro-fs has significant sequence similarity to the DNA binding loop of nuclear factor kappa B (NF-kappaB), which is known to bind thioredoxin (Trx). We hypothesize that the putative HIV-1 pro-fs gene product functions by mimicry of NF-kappaB via binding to Trx. The hypothesis was tested in vitro by co-immunoprecipitation and GST-pull down assays, using a purified mutant pro-fs protein, in which the two potential selenocysteine residues were mutated to cysteines, in order to permit expression in bacteria. Both experiments showed that pro-fs binds to human wild type Trx (Trx-wt) with high affinity. Mutation of the two conserved cysteine residues in the Trx active site redox center to serine (Ser) (Trx-CS) weakened but failed to abolish the interaction. In pro-fs-transfected 293T cells, using confocal microscopy and fluorescence resonance energy transfer (FRET), we have observed that pro-fs localizes in cell nuclei and forms oligomers. Upon stimulation by phorbol 12-myristate 13-acetate (PMA), Trx translocates into cell nuclei. Significant FRET efficiency was detected in the nuclei of PMA-stimulated 293T cells co-expressing fluorescence-tagged pro-fs and Trx-wt or Trx-CS. These results indicate that in living cells the double cysteine mutant of pro-fs binds to both Trx and Trx-CS with high affinity, suggesting that Trx-pro-fs binding is a structurally-specific interaction, involving more of the Trx molecule than just its active site cysteine residues. These results establish the capacity for functional mimicry of the Trx binding ability of the NF-kappaB/Rel family of transcription factors by the putative HIV-1 pro-fs protein.


Asunto(s)
VIH-1/química , FN-kappa B/metabolismo , Péptidos/metabolismo , Proteínas de los Retroviridae/metabolismo , Tiorredoxinas/metabolismo , Animales , Sitios de Unión , Células Cultivadas , Cisteína/genética , Escherichia coli/genética , Transferencia Resonante de Energía de Fluorescencia , Glutatión Transferasa/genética , Glutatión Transferasa/metabolismo , Humanos , Inmunoprecipitación , Mamíferos , Imitación Molecular , Mutación , Péptidos/química , Péptidos/genética , Proteínas de los Retroviridae/química , Proteínas de los Retroviridae/genética , Proteínas de los Retroviridae/aislamiento & purificación
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