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1.
Molecules ; 26(21)2021 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-34771142

RESUMEN

Fruit peels, pericarps, or rinds are rich in phenolic/polyphenolic compounds with antioxidant properties and potentially beneficial effects against obesity and obesity-related non-communicable diseases. This study investigated the anti-obesity effects of matoa (Pometia pinnata) and salak (Salacca zalacca) fruit peel. Neither matoa peel powder (MPP) nor salak peel powder (SPP) affected the body weight, visceral fat weight, or serum glucose or lipid levels of Sprague-Dawley rats when included as 1% (w/w) of a high-fat diet (HFD). However, MPP significantly decreased the hepatic lipid level. MPP at a dose of 3% (w/w) of the HFD decreased body weight, visceral fat, and serum triglyceride levels as well as the hepatic lipid content. The inhibitory effect of MPP on hepatic lipid accumulation was not enhanced when its concentration was increased from 1% to 3% of the HFD. The anti-obesity effect of matoa was partly explained by the inhibitory effect of the matoa peel extract on fatty acid-induced secretion of ApoB-48 protein, a marker of intestinal chylomicrons, in differentiated Caco-2 cell monolayers. We identified hederagenin saponins that are abundant in MPP as potential anti-obesity substances. These results will contribute towards the development of functional foods with anti-obesity effects using the matoa fruit peel.


Asunto(s)
Fármacos Antiobesidad/farmacología , Frutas/química , Obesidad/tratamiento farmacológico , Sapindaceae/química , Animales , Fármacos Antiobesidad/química , Fármacos Antiobesidad/aislamiento & purificación , Dieta Alta en Grasa/efectos adversos , Masculino , Obesidad/inducido químicamente , Polvos , Ratas , Ratas Sprague-Dawley
2.
Molecules ; 25(15)2020 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-32756488

RESUMEN

The young leaves of green tea become lighter in color than usual when protected from sunlight by a shading net for about two weeks while growing. These leaves are called "shaded white leaf tea" or SWLT. In the eluate of SWLT, the amount of amino acids (361 mg/L) was significantly higher than that in regular tea (53.5 mg/L). Since theanine and arginine, the first and second most abundant amino acids in SWLT, have significant antistress effects, we examined the antistress effect of SWLT on humans. SWLT or placebo green tea (3 g) was eluted with room-temperature water (500 mL). Participants consumed the tea for one week prior to pharmacy practice and continued for 10 days in the practice period. The state-trait anxiety inventory, an anxiety questionnaire, tended to be scored lower in the SWLT group than the placebo, but other stress markers showed no differences. The effect of the difference in SWLT components examined with mice showed that aspartic acid and asparagine, which are abundant in SWLT, counteracted the antistress effects of theanine and arginine. Large amounts of caffeine also interfered with SWLT's antistress effect. Thus, SWLT, which is high in caffeine and amino acids, suppressed depressant behavior in mice.


Asunto(s)
Aminoácidos/química , Antidepresivos/uso terapéutico , Cafeína/química , Estrés Psicológico/tratamiento farmacológico , Té/química , Aminoácidos/aislamiento & purificación , Amilasas/metabolismo , Animales , Antidepresivos/química , Antidepresivos/aislamiento & purificación , Antidepresivos/farmacología , Arginina/aislamiento & purificación , Arginina/uso terapéutico , Conducta Animal/efectos de los fármacos , Cafeína/aislamiento & purificación , Catequina/química , Catequina/aislamiento & purificación , Femenino , Glutamatos/aislamiento & purificación , Glutamatos/uso terapéutico , Humanos , Masculino , Ratones , Efecto Placebo , Extractos Vegetales/química , Hojas de la Planta/química , Hojas de la Planta/metabolismo , Estrés Psicológico/patología , Té/metabolismo , Adulto Joven
3.
Biosci Biotechnol Biochem ; 80(10): 1883-6, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27296359

RESUMEN

The inhibitory effect of 13 taxanes isolated from the Chinese yew (Taxus chinensis var. mairei) on the proliferation of human cervical cancer HeLa cells were examined using an MTT assay. Four compounds having a hydrophobic cinnamate side chain showed antiproliferative activity, which may be due to increased cell permeability.


Asunto(s)
Antineoplásicos/química , Antineoplásicos/farmacología , Hidrocarburos Aromáticos con Puentes/química , Diterpenos/química , Diterpenos/farmacología , Taxoides/química , Taxus/química , Neoplasias del Cuello Uterino/patología , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Femenino , Células HeLa , Humanos , Interacciones Hidrofóbicas e Hidrofílicas
4.
Phys Rev Lett ; 108(14): 141101, 2012 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-22540781

RESUMEN

The thermal fluctuation of mirror surfaces is the fundamental limitation for interferometric gravitational wave (GW) detectors. Here, we experimentally demonstrate for the first time a reduction in a mirror's thermal fluctuation in a GW detector with sapphire mirrors from the Cryogenic Laser Interferometer Observatory at 17 and 18 K. The detector sensitivity, which was limited by the mirror's thermal fluctuation at room temperature, was improved in the frequency range of 90 to 240 Hz by cooling the mirrors. The improved sensitivity reached a maximum of 2.2×10(-19) m/√Hz at 165 Hz.

5.
Nihon Rinsho ; 70(3): 394-8, 2012 Mar.
Artículo en Japonés | MEDLINE | ID: mdl-22514914

RESUMEN

In order to assess an effective dose, it is necessary to evaluate the external exposure caused by gamma ray or neutron, and the internal exposure caused by ingestion from contaminated food or soil and inhalation from radioactive fallout. It is also necessary to consider the equivalent dose of the skin in case of the existence of a high density surface contamination by beta emitters. An early evaluation on the effective dose should be indispensable by a dose calculation using easy expression and by a suitable radiation measurement for the radiation emergency. The accuracy of the effective dose may not be significant at the first stage, but the true value should be included in the range of the fluctuation. Here, radiation measurement is the most effective means to be able to avoid the misjudgment.


Asunto(s)
Radiometría/métodos , Adulto , Anciano , Niño , Preescolar , Humanos , Persona de Mediana Edad
6.
Nutrients ; 14(13)2022 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-35807759

RESUMEN

The single nucleotide polymorphisms (SNPs) rs3808607, rs2072183, rs2032582, and rs1761667 are associated with coenzyme Q10 (CoQ10) bioavailability in women after long-term CoQ10 supplementation. However, the beneficial aspects of the association between these SNPs and CoQ10 supplementation remain unknown. We investigated their relationship using the subjective quality of life score SF-36 by reanalyzing previous data from 92 study participants who were receiving ubiquinol (a reduced form of CoQ10) supplementation for 1 year. Two-way repeated-measures analysis of variance revealed a significant interaction between rs1761667 and the SF-36 scores of role physical (p = 0.016) and mental health (p = 0.017) in women. Subgrouping of participants based on the above four SNPs revealed significant interactions between these SNPs and the SF-36 scores of general health (p = 0.045), role emotional (p = 0.008), and mental health (p = 0.019) and increased serum CoQ10 levels (p = 0.008), suggesting that the benefits of CoQ10 supplementation, especially in terms of psychological parameters, are genotype-dependent in women. However, significant interactions were not observed in men. Therefore, inclusion of SNP subgrouping information in clinical trials of CoQ10 supplementation may provide conclusive evidence supporting other beneficial health effects exerted by the association between these SNPs and CoQ10 on women.


Asunto(s)
Calidad de Vida , Ubiquinona , Subfamilia B de Transportador de Casetes de Unión a ATP , Antioxidantes , Disponibilidad Biológica , Colesterol 7-alfa-Hidroxilasa , Suplementos Dietéticos , Femenino , Humanos , Masculino , Proteínas de Transporte de Membrana
7.
Antioxidants (Basel) ; 10(3)2021 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-33799730

RESUMEN

Coenzyme Q10 (CoQ10), an essential component for energy production that exhibits antioxidant activity, is considered a health-supporting and antiaging supplement. However, intervention-controlled studies have provided variable results on CoQ10 supplementation benefits, which may be attributed to individual CoQ10 bioavailability differences. This study aimed to investigate the relationship between genetic polymorphisms and CoQ10 serum levels after long-term supplementation. CoQ10 levels at baseline and after one year of supplementation (150 mg) were determined, and eight single nucleotide polymorphisms (SNPs) in cholesterol metabolism and CoQ10 absorption, efflux, and cellular uptake related genes were assessed. Rs2032582 (ABCB1) and rs1761667 (CD36) were significantly associated with a higher increase in CoQ10 levels in women. In addition, in women, rs3808607 (CYP7A1) and rs2072183 (NPC1L1) were significantly associated with a higher increase in CoQ10 per total cholesterol levels. Subgroup analyses showed that these four SNPs were useful for classifying high- or low-responder to CoQ10 bioavailability after long-term supplementation among women, but not in men. On the other hand, in men, no SNP was found to be significantly associated with increased serum CoQ10. These results collectively provide novel evidence on the relationship between genetics and CoQ10 bioavailability after long-term supplementation, which may help understand and assess CoQ10 supplementation effects, at least in women.

8.
BMC Ecol Evol ; 21(1): 115, 2021 06 09.
Artículo en Inglés | MEDLINE | ID: mdl-34187356

RESUMEN

BACKGROUND: The taxonomic classification of the suborder Tintinnina Kofoid & Campbell, 1929, a species-rich group of planktonic ciliated protistans with a characteristic lorica, has long been ambiguous largely due to the lack of cytological and molecular data for most species. Tintinnopsis is the largest, most widespread, and most taxonomically complex genus within this group with about 170 species occurring in nearshore waters. Previous molecular phylogenetic studies have revealed that Tintinnopsis is polyphyletic. RESULTS: Here we document the live morphology, infraciliature, gene sequences, and habitat characteristics of three poorly known tintinnine species, viz. Tintinnopsis karajacensis Brandt, 1896, Tintinnopsis gracilis Kofoid & Campbell, 1929, and Tintinnopsis tocantinensis Kofoid & Campbell, 1929, isolated from the coastal waters of China. Based on a unique cytological feature (i.e., an elongated ciliary tuft with densely arranged kinetids) in the former two species, Antetintinnopsis gen. nov. is erected with Antetintinnopsis hemispiralis (Yin, 1956) comb. nov. (original combination: Tintinnopsis hemispiralis Yin, 1956) designated as the type species. Moreover, A. karajacensis (Brandt, 1896) comb. nov. (original combination: Tintinnopsis karajacensis Brandt, 1896) and A. gracilis (Kofoid & Campbell, 1929) comb. nov. (original combination: Tintinnopsis gracilis Kofoid & Campbell, 1929) are placed in a highly supported clade that branches separately from Tintinnopsis clades in phylogenetic trees based on SSU rDNA and LSU rDNA sequence data, thus supporting the establishment of the new genus. One other species is assigned to Antetintinnopsis gen. nov., namely A. subacuta (Jörgensen, 1899) comb. nov. (original combination Tintinnopsis subacuta Jörgensen, 1899). CONCLUSIONS: The findings of the phylogenetic analyses support the assertion that cytological characters are taxonomically informative for tintinnines. This study also contributes to the broadening of our understanding of the tintinnine biodiversity and evolution.


Asunto(s)
Cilióforos , Biodiversidad , Cilióforos/genética , ADN Ribosómico/genética , Filogenia , Plancton
9.
J Nutr Metab ; 2020: 5349086, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31998536

RESUMEN

Coenzyme Q10 (CoQ10) is an essential compound that is involved in energy production and is a lipid-soluble antioxidant. Although it has been proposed as an antiaging and a health-supporting supplement, its low bioavailability remains a significant issue. Concurrent food intake enhances the absorption of orally administered CoQ10, but it has not been fully established whether specific food substances affect intestinal CoQ10 absorption. Therefore, to determine whether the bioavailability of supplemental CoQ10 is affected by diet, P30, a granulated and reduced form of CoQ10, was dispersed in four different foods, clear soup, miso soup, milk soup, and raw egg sauce. Those foods which contained CoQ10 were consumed on different occasions at intervals of 6-14 weeks by the same participants. Thirteen participants were recruited in the single-dose and repeated clinical study. When miso soup containing P30 was provided, the serum CoQ10 concentration increased faster than when participants consumed other P30-containing soups or a P30-containing raw egg sauce. The area under the curve for serum CoQ10 during the first 5 h after consumption of the P30-containing miso soup was approximately 1.5 times larger than those after the consumption of other P30-containing meals. These data imply that the absorption of CoQ10 supplements can be enhanced by consuming them with food and in particular with specific food substances, such as miso soup.

10.
Front Plant Sci ; 11: 611140, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33537046

RESUMEN

Plant albinism causes the etiolation of leaves because of factors such as deficiency of chloroplasts or chlorophylls. In general, albino tea leaves accumulate higher free amino acid (FAA) contents than do conventional green tea leaves. To explore the metabolic changes of etiolated leaves (EL) in the light-sensitive Japanese albino tea cultivar "Koganemidori," we performed integrated metabolome and transcriptome analyses by comparing EL with green leaves induced by bud-sport mutation (BM) or shading treatments (S-EL). Comparative omics analyses indicated that etiolation-induced molecular responses were independent of the light environment and were largely influenced by the etiolation itself. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment and pathway analyses revealed the downregulation of genes involved in chloroplast development and chlorophyll biosynthesis and upregulation of protein degradation-related pathways, such as the ubiquitin-proteasome system and autophagy in EL. Metabolome analysis showed that most quantified FAAs in EL were highly accumulated compared with those in BM and S-EL. Genes involved in the tricarboxylic acid (TCA) cycle, nitrogen assimilation, and the urea cycle, including the drastically downregulated Arginase-1 homolog, which functions in nitrogen excretion for recycling, showed lower expression levels in EL. The high FAA contents in EL might result from the increased FAA pool and nitrogen source contributed by protein degradation, low N consumption, and stagnation of the urea cycle rather than through enhanced amino acid biosynthesis.

11.
Front Plant Sci ; 11: 556476, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33240292

RESUMEN

Shade cultivation is a traditional Japanese tea cultivation method in which the shoot buds are shaded for several weeks. This technique is increasingly used for green tea production because it produces tea of high quality (as indicated by umami and nutritional content) and commands high prices. However, given that shaded tea plants are grown under low-light stress, concerns exist regarding damage to tea plants caused by repeated shade cultivation. To understand basic physiological responses and accumulative changes in photosynthetic ability and metabolites of tea plants subjected to repeated shading, we performed a pot experiment on immature tea plants grown in a growth chamber subjected to repeated shading treatments. The results demonstrated that shade cultivation caused a decrease in non-structural carbohydrate content and an increase of several degrees in leaf surface temperature, reflecting transpiration through the leaf stomata, as a result of a reduction in photosynthetic ability. An increase of several degrees in canopy temperature and a reduction in photosynthetic ability in the field in the mid-summer season was also observed in overstressed tea plants subjected to repeated shading. Metabolomic analysis identified several candidate biomarkers, such as citrulline and glycine betaine, that were significantly changed in individuals affected by shade cultivation. These physiological changes may be an indicator of the stress status of tea plants grown under repeated shade cultivation.

12.
Connect Tissue Res ; 50(5): 323-9, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19863391

RESUMEN

Delayed healing of skin wounds can be caused by wound instability, whereas appropriate massage or exercise prevents sclerosis and scar contracture. However, the mechanism by which wound healing is related to mechanical stress has not been fully elucidated. The present study aimed to identify whether mechanical stretching of fibroblasts reduces their production of extracellular matrix. We transferred skin fibroblasts into collagen-coated elastic silicone chambers, cultured them on a stretching apparatus, and used RT-PCR to examine the effects of mechanical stretching on the expression levels of 17 genes related to extracellular matrix production and growth factor secretion. We found that connective tissue growth factor (CTGF) was downregulated after 24 hr of cell stretching. Specifically, the CTGF mRNA and protein levels were 50% and 48% of the control levels, respectively. These findings suggest that cyclic stretching of fibroblasts contributes to anti-fibrotic processes by reducing CTGF production.


Asunto(s)
Cicatriz/genética , Factor de Crecimiento del Tejido Conjuntivo/genética , Fibroblastos/metabolismo , Piel/metabolismo , Cicatrización de Heridas/genética , Adolescente , Adulto , Células Cultivadas , Preescolar , Cicatriz/metabolismo , Cicatriz/fisiopatología , Factor de Crecimiento del Tejido Conjuntivo/metabolismo , Regulación hacia Abajo/genética , Matriz Extracelular/metabolismo , Proteínas de la Matriz Extracelular/genética , Proteínas de la Matriz Extracelular/metabolismo , Femenino , Fibroblastos/citología , Regulación de la Expresión Génica/genética , Humanos , Masculino , Periodicidad , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Piel/citología , Estrés Mecánico
13.
Protein Pept Lett ; 16(3): 301-5, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19275745

RESUMEN

We screened SMG7-binding peptides with phage display and docking simulation analysis. Although a consensus motif was absent in the phage display-derived candidates, we succeeded to find a peptide CDDRPPKSC, which can bind specifically to SMG7. We conclude that docking simulation helps to find high-affinity peptides efficiently, even if the phage display-screened candidates lack a consensus region.


Asunto(s)
Proteínas Portadoras/metabolismo , Péptidos/metabolismo , Simulación por Computador , Humanos , Biblioteca de Péptidos , Unión Proteica
14.
Biosci Biotechnol Biochem ; 73(10): 2341-4, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19809165

RESUMEN

We found increased expression of GRP94, the 94-kDa glucose-regulated protein, in HeLa cells 24 h after treatment with luteolin. Luteolin increased the levels of GRP94 mRNA and protein, but it did not increase the expression of unfolded protein response (UPR)-regulated genes. In addition, luteolin also enhanced GRP94 promoter activity, suggesting that it enhances the expression of GRP94 at the transcriptional level, not via the UPR signaling pathway.


Asunto(s)
Proteínas HSP70 de Choque Térmico/genética , Proteínas HSP70 de Choque Térmico/metabolismo , Luteolina/farmacología , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Regulación hacia Arriba/efectos de los fármacos , Células HeLa , Humanos , ARN Mensajero/genética , ARN Mensajero/metabolismo
15.
Biochem Biophys Res Commun ; 369(3): 948-52, 2008 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-18328256

RESUMEN

To find novel proteins involved in radio-resistance of human cells, we searched for nuclear proteins, whose expression levels alter after X-ray irradiation in HeLa cells, using agarose fluorescent two-dimensional differential gel electrophoresis following mass spectrometry. We identified 6 proteins, whose levels were increased in nuclei 24h after irradiation at 5Gy, including aldolase A. Nuclear aldolase A levels increased twofold after the irradiation, however, total aldolase A levels did not change. When the expression of aldolase A was suppressed by its specific siRNA, sensitization of the suppressed cells to X-ray-induced cell death was observed. In addition, UV(r)-1 cells with higher aldolase A expression exhibited lower sensitivity to X-ray-induced cell death than the parental RSa cells with lower aldolase A expression. These results suggest that aldolase A may play a role in the radio-response of human cells, probably in nuclei, in addition to its glycolytic role in the cytosol.


Asunto(s)
Fructosa-Bifosfato Aldolasa/fisiología , Tolerancia a Radiación , Rayos X , Núcleo Celular/enzimología , Núcleo Celular/efectos de la radiación , Fructosa-Bifosfato Aldolasa/antagonistas & inhibidores , Fructosa-Bifosfato Aldolasa/genética , Células HeLa , Humanos , Proteómica , ARN Interferente Pequeño/farmacología , Tolerancia a Radiación/efectos de los fármacos , Tolerancia a Radiación/genética
16.
Biosci Biotechnol Biochem ; 72(9): 2432-5, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18776667

RESUMEN

We investigated changes in the sub-cellular distribution of glycelaldehyde-3-phosphate dehydrogenase (GAPDH) after X-ray irradiation in HeLa cells. Twenty-four h after irradiation at 5 Gy, nuclear GAPDH levels increased 2.6-fold, whereas total GAPDH levels increased only 1.2-fold. Knockdown of GAPDH using specific small interfering RNA (siRNA) led to sensitization to X-ray-induced cell death. These results suggest that GAPDH plays a role in the radioresponse.


Asunto(s)
Gliceraldehído-3-Fosfato Deshidrogenasas/genética , Tolerancia a Radiación/genética , Rayos X , Supervivencia Celular/efectos de la radiación , Gliceraldehído-3-Fosfato Deshidrogenasas/metabolismo , Células HeLa , Humanos , ARN Interferente Pequeño/farmacología , Tolerancia a Radiación/efectos de los fármacos , Transfección
17.
Arch Biochem Biophys ; 468(1): 1-14, 2007 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-17936241

RESUMEN

The 78-kDa glucose-regulated protein GRP78 is a central regulator of endoplasmic reticulum (ER) homeostasis, functioning in protein folding, ER calcium binding and modulation of transmembrane ER stress sensor activity. ER stress uncouples the interaction between GRP78 and ER stress sensors, leading to activation of the unfolded protein response (UPR), including upregulation of ER chaperone proteins. In the present study, we observed unexpected and remarkable induction of glucose-regulated protein 94 (GRP94) in HeLa cells following their transfection with 2'-O-methyl-modified siRNA specific to GRP78 mRNA. Additionally, we found that this siRNA also increased the expression of other UPR-induced genes, such as CHOP, ERdj4 and P5. Activation of UPR-dependent transcription and induction of apoptosis were also observed in cells transfected with GRP78 siRNA. Induction of apoptosis by GRP78 siRNA was also observed in PC-3 cells, which expressed high basal levels of GRP78 protein similar to that observed in HeLa cells. By contrast, five other human cell lines with lower basal expression of GRP78 protein did not undergo apoptosis when treated with GRP78 siRNA. Possible reasons for the strong activation of the UPR and apoptosis induced by GRP78 knockdown in HeLa cells, and the therapeutic utility of 2'-O-methyl-modified GRP78 siRNAs in anticancer treatment, are discussed.


Asunto(s)
Apoptosis/genética , Silenciador del Gen , Proteínas de Choque Térmico/genética , Chaperonas Moleculares/genética , ARN Interferente Pequeño/genética , Regulación hacia Abajo/genética , Chaperón BiP del Retículo Endoplásmico , Células HeLa , Humanos , Desnaturalización Proteica , Pliegue de Proteína
18.
Phys Med Biol ; 52(17): 5249-61, 2007 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-17762084

RESUMEN

Annihilation photon acollinearity is a fundamental but little investigated problem in positron emission tomography (PET). In this paper, the cause of the angular deviation from 180.00 degrees is described as well as how to evaluate it under conditions of a spatially distributed radiation source and a limited acquisition time for the human body. A relationship between the shape of the photopeak spectrum and the angular distribution is formulated using conservation laws of momentum and energy over the pair annihilation. Then the formula is used to evaluate the acollinearity for a pool phantom and the human body with FDG injected. The angular distribution for the pool phantom agrees well with that for pure water which had been directly measured by Colombino et al in 1965 (Nuovo Cimento 38 707-23), and also with that for the human body determined in this study. Pure water can be considered as a good approximation of the human body regarding the angular deviation. The blurring coefficient to be multiplied by the ring diameter in calculations of the PET spatial resolution is experimentally determined for the first time as 0.00243 +/- 0.00014; this is 10% larger than the value widely used by investigators.


Asunto(s)
Algoritmos , Artefactos , Fluorodesoxiglucosa F18 , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Modelos Biológicos , Tomografía de Emisión de Positrones/métodos , Simulación por Computador , Humanos , Modelos Estadísticos , Fantasmas de Imagen , Fotones , Radiofármacos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
19.
Health Phys ; 113(3): 220-224, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28749812

RESUMEN

Monazite is a naturally occurring radioactive material that is processed for use in a variety of domestic applications. At present, there is little information available on potential radiation doses experienced by people working with monazite. The ambient dose rate and activity concentration of natural radionuclides in raw materials, products, and dust in work sites as well as the Rn and Rn concentrations in work sites were measured in a monazite processing plant in Japan. Dose estimations for plant workers were also conducted. The activity concentration of the U series in raw materials and products for the monazite processing plant was found to be higher than the relevant values described in the International Atomic Energy Agency Safety Standards. The ambient dose rates in the raw material yard were higher than those in other work sites. Moreover, the activity concentrations of dust in the milling site were higher than those in other work sites. The Rn concentrations in all work sites were almost the same as those in regular indoor environments in Japan. The Rn concentrations in all work sites were much higher than those in regular indoor environments in Japan. The maximum value of the effective dose for workers was 0.62 mSv y, which is lower than the reference level range (1-20 mSv y) for abnormally high levels of natural background radiation published in the International Commission of Radiological Protection Publication 103.


Asunto(s)
Metales de Tierras Raras/química , Monitoreo de Radiación , Radiación de Fondo , Polvo/análisis , Humanos , Japón , Radiactividad
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