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1.
J Phys Chem A ; 128(6): 1041-1048, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38311924

RESUMEN

To determine the H-abstraction reaction probabilities of H/O/OH radicals with a polypropylene (PP) surface, a first-principles calculation was performed based on the DLPNO-CCSD(T)/CBS//M06-2X-D3/def-TZVP theory level. The PP chain model used in this study was 2,4,6-trimethylheptane. The rate constants of the H/O/OH radicals with the isolated PP chain model were calculated based on the conventional transition-state theory. By comparing the experimental values and considering the error factors and their compensation, it was concluded that the orders of magnitude of the predicted rate constants were accurate. The resulting rate constants were converted to reaction probabilities between the H/O/OH radicals and the PP surface. The method used in this study is applicable for obtaining theoretical values of surface reaction probabilities based on first-principles calculations. The calculation at the DLPNO-CCSD(T)/CBS theory level has high accuracy but consumes a large amount of computational resources. The study also demonstrated that the double-hybrid functionals, wB97x-2-D3(BJ) and rev-DSD-PBEP86-D3(BJ), with a 3-ζ or 4-ζ basis set, could reproduce the electronic energy values obtained from DLPNO-CCSD(T)/CBS while using only approximately 1/100 of the computational resources required by the latter under our computer configuration.

2.
Biol Pharm Bull ; 39(3): 415-22, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26934931

RESUMEN

Public concern regarding the transport of air pollutants from mainland East Asia to the leeward area by the prevailing westerlies in spring and winter monsoon has been growing in recent years. We collected total suspended particle (TSP) in Beijing, a metropolis of China located windward of Japan, in spring (late February 2011-May 2011) and in winter (November 2012-early February 2013), then analyzed metals, ions, and organic compounds and mutagenicity, and compared the pollution levels with samples collected at two Japanese metropolises (Osaka and Nagoya) during the same periods. The medians of concentration of TSP and other factors in Beijing were much larger than those in the Japanese metropolises. Especially, the concentrations of polycyclic aromatic hydrocarbons (PAHs) were remarkably high in Beijing in winter, and the median of total PAHs concentration in Beijing was 62-63 times larger than that in the Japanese sites. The mutagenicity of TSP from Beijing toward Salmonella typhimurium YG1024, with and without a mammalian metabolic system (S9 mix), was 13-25 times higher than that from the Japanese sites in winter. These results suggest that air pollution levels in Beijing are very high compared with those at the two Japanese metropolises we evaluated. The diagnostic ratios of PAHs and nitrated polycyclic aromatic hydrocarbons (NPAHs) suggest that the major sources of PAHs and NPAHs in Beijing are different from those at the two Japanese sites in winter, and that the major source in Beijing is coal/biomass combustion.


Asunto(s)
Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Mutágenos/análisis , China , Ciudades , Monitoreo del Ambiente , Hierro/análisis , Japón , Plomo/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Estaciones del Año
3.
Gan To Kagaku Ryoho ; 40(12): 1993-5, 2013 Nov.
Artículo en Japonés | MEDLINE | ID: mdl-24393990

RESUMEN

The patient was a 68-year-old man who had undergone sigmoidectomy 1 year previously. Adjuvant therapy with tegafur- uraci(l UFT) and Leucovorin( UZEL) was administered. Seven months later, the carcinoembryonic antigen( CEA) level increased to 7.5 ng/mL. Enhanced computed tomography (CT) revealed a 4-cm mass in the mesorectum, and the patient was diagnosed as having local recurrence. Chemotherapy with oxaliplatin, 5-fluorouracil, and Leucovorin( mFOLFOX6) and radiation therapy( 60 Gy) were administered. As the tumor could not be detected after chemoradiotherapy, abdominoperineal resection was performed. Pathological examination showed no cancer and indicated a complete response. The patients CEA level has not increased and no recurrence has been detected on enhanced CT for 3.5 years. The tumor could be decreased in size by chemoradiotherapy and the operation could be safely performed without resecting other organs. Although surgery is generally performed for local recurrence, multidisciplinary therapy could be useful in performing such surgery safely.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Quimioradioterapia , Neoplasias del Recto/terapia , Neoplasias del Colon Sigmoide/patología , Anciano , Humanos , Masculino , Neoplasias del Recto/secundario , Recurrencia , Inducción de Remisión , Neoplasias del Colon Sigmoide/tratamiento farmacológico , Neoplasias del Colon Sigmoide/cirugía
4.
Biointerphases ; 10(2): 029514, 2015 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-25934074

RESUMEN

The atmospheric-pressure helium plasma jet is an emerging technology for plasma biomedical applications. In this paper, the authors focus on the effect of discharge polarity on propagation of the discharge and the densities of OH, NO, and O radicals. The plasma jet is applied to a glass surface placed on a grounded metal plate. Positive or negative voltage pulses with 25 µs duration, 8 kV amplitude, and 10 kpps repetition rate are used for the plasma jet. The plasma propagation is measured using a short-gated ICCD camera. The light emission intensity of the discharge generated at the rising phase of the voltage pulse is approximately equivalent for both polarities, while that generated during the falling phase is much higher for the negative discharge than the positive one. The shape of the discharge changes with the discharge polarity. The OH, NO, and O densities in the plasma jet are also measured for both polarities. It is found that the OH density is almost the same regardless the discharge polarity. Conversely, the negative discharge produces more O atoms and the positive discharge produces more NO molecules. These results indicate that the polarity of the discharge affects the densities of some reactive species produced in the plasma jet.


Asunto(s)
Electricidad , Radicales Libres/análisis , Helio , Hidróxidos/análisis , Óxidos de Nitrógeno/análisis , Gases em Plasma/química , Especies Reactivas de Oxígeno/análisis , Presión Atmosférica
5.
Biosystems ; 109(3): 420-9, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22613512

RESUMEN

Canalization is a typical self-organization process leading to complementarity between parts and the whole. In the field of developmental biology, concerns about morphogenesis canalization are often framed as the French flag problem, questioning how each cell knows its own position in the whole system. Although chemical gradients have been suggested to provide positional information, there is no direct evidence that gradients are used to gain positional information. The chemical gradient hypothesis is based on the assumption that agents (e.g., cells) in a domain that locally interact with each other can generate a chemical gradient thanks to a global reference point. Instead of a chemical gradient, we here propose a model based on agents that are equipped with sociality that is based not on a global reference but rather on the ability to sense other neighboring agents, or potential resonance. The interaction among the agents with sociality, developed from undifferentiated types or tokens, is implemented using asynchronous updating automata equipped with potential resonance. We show that these automata can generate a French flag pattern that is very robust against perturbations without positional information by comparing automata with synchronous updating and asynchronous automata without potential resonance.


Asunto(s)
Comunicación Celular/fisiología , Diferenciación Celular/fisiología , Movimiento Celular/fisiología , Modelos Biológicos , Morfogénesis/fisiología , Animales , Simulación por Computador , Factores de Tiempo
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