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1.
Phys Chem Chem Phys ; 25(29): 19666-19683, 2023 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-37436136

RESUMEN

A Janus metastructure (MS) assisted by a waveguide structure (WGS) resting on anapole modes and exhibiting direction-dependent behavior has been developed in the terahertz (THz) region. Ultra-broadband absorption is formed by the destructive interference through the anapole as well as Janus trait and is shaped by nested WGS. In this design, vanadium dioxide (VO2) is expected to attain functional transformation from plasmon-induced transparency (PIT) to absorption. The insulating nature of the VO2 results in the creation of the PIT, which is characterized by a wide and high transmission window ranging from 1.944 THz to 2.284 THz, corresponding to the relative bandwidth of 7.4% above 0.9. However, when the VO2 reaches the metallic state, a high absorptivity of 0.921 at 2.154 THz can be implemented in the -z-direction owing to the excitement of the toroidal dipole and electric dipole moments in the near-infrared region. And in the +z-direction, the broadband absorption above 0.9 in the 1.448-2.497 THz range takes shape in virtue of surface plasmon polariton modes, in which intensely localized oscillation of free electrons is confined to the metal-dielectric interface supported by the WGS. Noting that the MS is equipped with a favorable sensitivity to the incidence angle, we develop an ultra-broadband backward absorption in the TM mode from 0.7-10 THz nearly all above 0.9 when the incidence angle changes from 30°-70°. Moreover, owing to the highly symmetrical structure, the MS exhibits exotic polarization angular stability. All the awesome properties make this MS a good candidate for various applications such as in electromagnetic wave steering, spectral analysis, and sensors.

2.
Chin Med J (Engl) ; 133(2): 141-147, 2020 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-31868806

RESUMEN

BACKGROUND: Super-responders (SRs) to cardiac resynchronization therapy (CRT) regain near-normal or normal cardiac function. The extent of cardiac synchrony of SRs and whether continuous biventricular (BIV) pacing is needed remain unknown. The aim of this study was to evaluate the cardiac electrical and mechanical synchrony of SRs. METHODS: We retrospectively analyzed CRT recipients between 2008 and 2016 in 2 centers to identify SRs, whose left ventricular (LV) ejection fraction was increased to ≥50% at follow-up. Cardiac synchrony was evaluated in intrinsic and BIV-paced rhythms. Electrical synchrony was estimated by QRS duration and LV mechanical synchrony by single-photon emission computed tomography myocardial perfusion imaging. RESULTS: Seventeen SRs were included with LV ejection fraction increased from 33.0 ±â€Š4.6% to 59.3 ±â€Š6.3%. The intrinsic QRS duration after super-response was 148.8 ±â€Š30.0 ms, significantly shorter than baseline (174.8 ±â€Š11.9 ms, P = 0.004, t = -3.379) but longer than BIV-paced level (135.5 ±â€Š16.7 ms, P = 0.042, t = 2.211). Intrinsic LV mechanical synchrony significantly improved after super-response (phase standard deviation [PSD], 51.1 ±â€Š16.5° vs. 19.8 ±â€Š8.1°, P < 0.001, t = 5.726; phase histogram bandwidth (PHB), 171.7 ±â€Š64.2° vs. 60.5 ±â€Š22.9°, P < 0.001, t = 5.376) but was inferior to BIV-paced synchrony (PSD, 19.8 ±â€Š8.1° vs. 15.2 ±â€Š6.4°, P = 0.005, t = 3.414; PHB, 60.5 ±â€Š22.9° vs. 46.0 ±â€Š16.3°, P = 0.009, t = 3.136). CONCLUSIONS: SRs had significant improvements in cardiac electrical and LV mechanical synchrony. Since intrinsic synchrony of SRs was still inferior to BIV-paced rhythm, continued BIV pacing is needed to maintain longstanding and synchronized contraction.


Asunto(s)
Terapia de Resincronización Cardíaca/métodos , Insuficiencia Cardíaca/terapia , Función Ventricular Izquierda/fisiología , Anciano , Femenino , Ventrículos Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Prohibitinas , Estudios Retrospectivos , Resultado del Tratamiento
3.
J Biomed Res ; 32(5): 361-370, 2018 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-29784899

RESUMEN

Sleepiness affects normal social life, which attracts more and more attention. Circadian phenotypes contribute to obvious individual differences in susceptibility to sleepiness. We aimed to identify candidate single nucleotide polymorphisms (SNPs) which may cause circadian phenotypes, elucidate the potential mechanisms, and generate corresponding SNP-gene-pathways. A genome-wide association studies (GWAS) dataset of circadian phenotypes was utilized in the study. Then, the Identify Candidate Causal SNPs and Pathways analysis was employed to the GWAS dataset after quality control filters. Furthermore, genotype-phenotype association analysis was performed with HapMap database. Four SNPs in three different genes were determined to correlate with usual weekday bedtime, totally providing seven hypothetical mechanisms. Eleven SNPs in six genes were identified to correlate with usual weekday sleep duration, which provided six hypothetical pathways. Our results demonstrated that fifteen candidate SNPs in eight genes played vital roles in six hypothetical pathways implicated in usual weekday bedtime and six potential pathways involved in usual weekday sleep duration.

4.
Bioorg Med Chem ; 20(14): 4316-22, 2012 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-22710102

RESUMEN

Nitroimidazoles and their derivatives have drawn continuing interest over the years because of their varied biological activities, recently found application in drug development for antimicrobial chemotherapeutics and antiangiogenic hypoxic cell radiosensitizers. In order to search for novel antibacterial agents, we designed and synthesized a series of secnidazole analogs based on oxadiazole scaffold (4-21). Among these compounds, 4 and 7-21 were reported for the first time. These compounds were tested for antibacterial activities against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus. This new nitroimidazole derivatives class demonstrated strong antibacterial activities. Escherichia coli ß-ketoacyl-acyl carrier protein synthase III (FabH) inhibitory assay and docking simulation indicated that the compounds 2-(2-methoxyphenyl)-5-((2-methyl-5-nitro-1H-imidazol-1-yl)methyl)-1,3,4-oxadiazole (11) with MIC of 1.56-3.13 µg/mL against the tested bacterial strains and 2-((2-methyl-5-nitro-1H-imidazol-1-yl)methyl)-5-(2-methylbenzyl)-1,3,4-oxadiazole (12) with MIC of 1.56-6.25 µg/mL were most potent inhibitors of Escherichia coli FabH.


Asunto(s)
Acetiltransferasas/antagonistas & inhibidores , Antiinfecciosos/síntesis química , Diseño de Fármacos , Inhibidores Enzimáticos/síntesis química , Proteínas de Escherichia coli/antagonistas & inhibidores , Nitroimidazoles/química , Oxadiazoles/química , 3-Oxoacil-(Proteína Transportadora de Acil) Sintasa , Acetiltransferasas/metabolismo , Antiinfecciosos/química , Antiinfecciosos/farmacología , Sitios de Unión , Simulación por Computador , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Escherichia coli/efectos de los fármacos , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Acido Graso Sintasa Tipo II/antagonistas & inhibidores , Acido Graso Sintasa Tipo II/metabolismo , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Nitroimidazoles/síntesis química , Nitroimidazoles/farmacología , Estructura Terciaria de Proteína , Relación Estructura-Actividad
5.
Bioorg Med Chem ; 19(18): 5708-15, 2011 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-21872479

RESUMEN

A series of novel Schiff base derivatives have been designed and synthesized, and their biological activities were also evaluated as potential inhibitors of FabH. These compounds were assayed for antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus. Compounds with potent antibacterial activities were tested for their E. coli FabH inhibitory activity. Compound 3v showed the most potent antibacterial activity with MIC of 1.56-6.25 µg/mL against the tested bacterial strains and exhibited the most potent E. coli FabH inhibitory activity with IC(50) of 4.3 µM. Docking simulation was performed to position compound 3v into the E. coli FabH active site to determine the probable binding conformation.


Asunto(s)
Antibacterianos/síntesis química , Antibacterianos/farmacología , Bases de Schiff/síntesis química , Bases de Schiff/farmacología , Tiourea/farmacología , Antibacterianos/química , Bacillus subtilis/efectos de los fármacos , Cristalografía por Rayos X , Relación Dosis-Respuesta a Droga , Escherichia coli/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Modelos Moleculares , Estructura Molecular , Pseudomonas aeruginosa/efectos de los fármacos , Bases de Schiff/química , Staphylococcus aureus/efectos de los fármacos , Estereoisomerismo , Relación Estructura-Actividad , Tiourea/análogos & derivados , Tiourea/química
6.
Eur J Med Chem ; 46(9): 4702-8, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21816517

RESUMEN

A series of novel chalcone thiosemicarbazide derivatives (4a-4x) have been designed, synthesized, structurally determined, and their biological activities were also evaluated as potential EGFR kinase inhibitors. All the synthesized compounds are first reported. Among the compounds, compound 4r showed the most potent biological activity (IC(50) = 0.78 ± 0.05 µM for HepG2 and IC(50) = 0.35 µM for EGFR), which is comparable to the positive controls. Docking simulation was also performed to position compound 4r into the EGFR active site to determine the probable binding model. Antiproliferative assay results demonstrated that some of these compounds possessed good antiproliferative activity against HepG2. Compound 4r with potent inhibitory activity in tumor growth inhibition may be a potential anticancer agent.


Asunto(s)
Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Chalconas/química , Semicarbacidas/síntesis química , Semicarbacidas/farmacología , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Cristalografía por Rayos X , Receptores ErbB/antagonistas & inhibidores , Humanos , Espectroscopía de Resonancia Magnética , Semicarbacidas/química , Espectrometría de Masa por Ionización de Electrospray
7.
Bioorg Med Chem ; 19(15): 4513-9, 2011 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-21741250

RESUMEN

A series of novel cinnamic acid secnidazole ester derivatives have been designed and synthesized, and their biological activities were also evaluated as potential inhibitors of FabH. These compounds were assayed for antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus. Compounds with potent antibacterial activities were tested for their E. coli FabH inhibitory activity. Compound 3n showed the most potent antibacterial activity with MIC of 1.56-6.25 µg/mL against the tested bacterial strains and exhibited the most potent E. coli FabH inhibitory activity with IC50 of 2.5 µM. Docking simulation was performed to position compound 3n into the E. coli FabH active site to determine the probable binding conformation.


Asunto(s)
3-Oxoacil-(Proteína Transportadora de Acil) Sintasa/antagonistas & inhibidores , Antibacterianos/química , Antibacterianos/farmacología , Bacterias/enzimología , Cinamatos/química , Cinamatos/farmacología , Metronidazol/análogos & derivados , 3-Oxoacil-(Proteína Transportadora de Acil) Sintasa/metabolismo , Antibacterianos/síntesis química , Bacterias/efectos de los fármacos , Infecciones Bacterianas/tratamiento farmacológico , Cinamatos/síntesis química , Humanos , Concentración 50 Inhibidora , Metronidazol/síntesis química , Metronidazol/química , Metronidazol/farmacología , Pruebas de Sensibilidad Microbiana , Simulación de Dinámica Molecular
8.
Bioorg Med Chem ; 19(15): 4413-20, 2011 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-21752655

RESUMEN

FabH, ß-ketoacyl-acyl carrier protein (ACP) synthase III, is a particularly attractive target, since it is central to the initiation of fatty acid biosynthesis and is highly conserved among Gram-positive and Gram-negative bacteria. A series of o-hydroxybenzylamines 1-16 and its corresponding new urea derivatives 17-32 were synthesized and fully characterized by spectroscopic methods and elemental analysis. This new urea derivatives class demonstrates strong antibacterial activity. Escherichia coli FabH inhibitory assay and docking simulation indicated that the compounds 1-(5-bromo-2-hydroxybenzyl)-1-(4-fluorophenyl)-3-phenylurea (18) and 1-(5-bromo-2-hydroxybenzyl)-1-(4-chlorophenyl)-3-phenylurea (20) were potent inhibitors of E. coli FabH.


Asunto(s)
3-Oxoacil-(Proteína Transportadora de Acil) Sintasa/antagonistas & inhibidores , Antibacterianos/química , Antibacterianos/farmacología , Bacterias/efectos de los fármacos , Bacterias/enzimología , Diseño de Fármacos , Urea/análogos & derivados , 3-Oxoacil-(Proteína Transportadora de Acil) Sintasa/metabolismo , Antibacterianos/síntesis química , Infecciones Bacterianas/tratamiento farmacológico , Infecciones Bacterianas/enzimología , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Escherichia coli/efectos de los fármacos , Escherichia coli/enzimología , Infecciones por Escherichia coli/tratamiento farmacológico , Infecciones por Escherichia coli/enzimología , Bacterias Gramnegativas , Humanos , Pruebas de Sensibilidad Microbiana , Modelos Moleculares , Unión Proteica
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