RESUMEN
We have developed a high-efficiency high-resolution particle-induced x-ray emission (PIXE) system employing a von Hamos-type crystal spectrometer for a chemical state identification of trace elements in environmental samples. The energy resolution of the system was determined to be about 0.05% through the observation of Si Kalpha(1,2) x rays (1.74 keV) from elemental silicon. The throughput efficiency of the system was also evaluated quasitheoretically to be 1.6x10(-7) counts/incident proton for Si Kalpha(1,2) emission. To demonstrate a chemical state analysis using the high-resolution PIXE system, Si Kalpha(1,2) and Kbeta x-ray spectra for SiC, Si(3)N(4), and SiO(2) were measured and compared. The observed chemical shifts of the Si Kalpha(1,2) peaks for SiC, Si(3)N(4), and SiO(2) relative to elemental silicon were 0.20, 0.40, and 0.55 eV, respectively. The tendency of these shifts were well explained by the effective charges of the silicon atoms calculated by a molecular orbital method.
Asunto(s)
Monitoreo del Ambiente/instrumentación , Microquímica/instrumentación , Manejo de Especímenes/instrumentación , Espectrometría por Rayos X/instrumentación , Monitoreo del Ambiente/métodos , Diseño de Equipo , Análisis de Falla de Equipo , Microquímica/métodos , Tamaño de la Partícula , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Manejo de Especímenes/métodos , Espectrometría por Rayos X/métodosRESUMEN
The present study was conducted to investigate the relationship between mandibular movement (lateral excursion and masticatory movements) and craniofacial morphology in 16 patients with mandibular deviation, using a six degrees-of-freedom measuring device. (i) Mandibular deviation was found to be significantly related to frontal maxillary and occlusal plane angles. (ii) Three-dimensional non-working condylar and incisal path lengths were longer during the lateral excursion to the non-deviated side than to the deviated side, and the incisal path moved antero-inferior. (iii) The lateral motion range of the incisal path was wider during masticatory movement on the non-deviated side than on the deviated side, and the molar and non-working condylar path lengths corresponding to the lateral range of the incisal path were also longer on the non-deviated side. The group with posterior crossbite showed a significantly smaller horizontal range of incisal path, and also significantly smaller frontal projected incisal and molar path angles during masticatory movement on the deviated side than on the non-deviated side. These results suggest that lateral excursion and masticatory movements could be related to craniofacial morphology and posterior crossbite.
Asunto(s)
Mandíbula/anomalías , Cóndilo Mandibular/fisiología , Prognatismo/cirugía , Adolescente , Adulto , Oclusión Dental , Femenino , Humanos , Técnicas de Fijación de Maxilares , Registro de la Relación Maxilomandibular , Maloclusión/cirugía , Mandíbula/fisiopatología , Mandíbula/cirugía , Cóndilo Mandibular/fisiopatología , Cóndilo Mandibular/cirugía , Masticación , Osteotomía/métodos , Rango del Movimiento Articular/fisiologíaRESUMEN
Kynurenine pathway of tryptophan makes a lot of physiological active substances, such as quinolinate, NAD and so on, suggesting that kynurenine itself may play a very important role physiologically. Therefore, we examined the influence of exercise on serum kynurenine concentration. At first, we assayed kynurenine concentration of students (n = 13) who took part in a rugby camp for three days. The mean value of kynurenine concentration of before and after training were 1.362 +/- 0.306 microM and 1.725 +/- 0.511 microM respectively. These data means that severe exercise rise the serum kynurenine concentration. Then we tried to examine the relationship between the level of exercise and serum kynurenine concentration. Serum kynurenine concentration had significantly increased immediately after the exercise from 1.869 +/- 0.285 microM to 2.138 +/- 0.248 microM of 24 hours later by loading of 65% heart rate max exercise for each subject. These results suggested that at least the severe exercise affect on the tryptophan metabolism. We will discuss the change of serum kynurenine concentration by another sports such as soccer game and 20 km run.
Asunto(s)
Ejercicio Físico/fisiología , Quinurenina/sangre , Cromatografía Líquida de Alta Presión , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Fútbol/fisiología , Triptófano/metabolismoRESUMEN
Betaine aldehyde dehydrogenase (BADH) catalyzes the last step in the plant biosynthetic pathway that leads to glycinebetaine. Rice plants (Oryza sativa L.), albeit considered a typical non-glycinebetaine accumulating species, have been found to express this enzyme at low levels. This observation evokes an interest in phylogenic evolution of the enzyme in the plant kingdom. It is reported here that rice plants possess the ability to take up exogenously added betaine aldehyde through the roots and convert it to glycinebetaine, resulting in an enhanced salt-tolerance of the plants. A gene encoding a putative BADH from the rice genome was also cloned and sequenced. The gene was found to contain 14 introns, and the overall nucleotide sequence of the coding region is c. 78% identical to that of the barley BADH cDNA. Cloning of a partial BADH cDNA from rice was accomplished by reverse transcription-polymerase chain reaction (RT-PCR). The nucleotide sequence of the cloned fragment was found to be identical to the corresponding exon regions of the rice genomic BADH gene. The deduced amino acid sequences of rice and barley BADH both contain a C-terminal tripeptide SKL, a signal known to target preproteins to microbodies. This localization was confirmed by an immuno-gold labeling study of transgenic tobacco harboring barley cDNA, which showed BADH protein inside peroxisomes. Northern blot analysis revealed that the level of BADH mRNA is salt-inducible.