Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Adicionar filtros








Intervalo de ano
1.
Korean Journal of Medical Physics ; : 191-198, 2009.
Artigo em Inglês | WPRIM | ID: wpr-227394

RESUMO

In this study, we evaluated an edge detector for small-beam dosimetry. We measured the dose linearity, dose rate dependence, output factor, beam profiles, and percentage depth dose using an edge detector (Model 1118 Edge) for 6-MV photon beams at different field sizes and depths. The obtained values were compared with those obtained using a standard volume ionization chamber (CC13) and photon diode detector (PFD). The dose linearity results for the three detectors showed good agreement within 1%. The edge detector had the best linearity of +/-0.08%. The edge detector and PFD showed little dose rate dependency throughout the range of 100~600 MU/min, while CC13 showed a significant discrepancy of approximately -5% at 100 MU/min. The output factors of the three detectors showed good agreement within 1% for the tested field sizes. However, the output factor of CC13 compared to the other two detectors had a maximum difference of 21% for small field sizes (~4x4 cm2). When analyzing the 20~80% penumbra, the penumbra measured using CC13 was approximately two times wider than that using the edge detector for all field sizes. The width measured using PFD was approximately 30% wider for all field sizes. Compared to the edge detector, the 10~90% penumbras measured using the CC13 and PFD were approximately 55% and 19% wider, respectively. The full width at half maximum (FWHM) of the edge detector was close to the real field size, while the other two detectors measured values that were 8~10% greater for all field sizes. Percentage depth doses measured by the three detectors corresponded to each other for small beams. Based on the results, we consider the edge detector as an appropriate small-beam detector, while CC13 and PFD can lead to some errors when used for small beam fields under 4x4 cm2.


Assuntos
Dependência Psicológica
2.
Korean Journal of Obstetrics and Gynecology ; : 606-613, 1997.
Artigo em Coreano | WPRIM | ID: wpr-185581

RESUMO

Recently, the ovary is known to be a center of paracrine and autocrine rehulating factors. IGF-I is a local regulator of follicular function and a poten stimulator of ovarian cell proliferation and differentiation, in synergy will the gonadotrophins, whilst GH may exert its effect by changing intra-ovarian IGF-I concentration. Inbiological fluids, IGFs are bound to specific, high affinity binding proteins(IGFBP). The IGFBPs are considered paracrine modulators of the action of IGF-I in the ovary. The aim of the study is to elucidate relationships amongst IGF-I, IGFBP-3, GH and estadiol in mature follicular fluids or serum. Thirty-six infertility patients who underwent ovulation induction program by GnRH agonist short or long protocol for in vitro fertilization (IVF) were examined to investigate the correlations amongst the concentration of IGF-I, IGFBP-3, GH and estradiol in follicular fluid or serum. These hormones were quantitatively anayzed by radioimmunoassay(RIA) or Immunoradiometric assay(IRMA). There were statistically significant correlations between the concentration of IGF-I and GH, IGFBP-3 in follicular fluid. Therefore, GH tends to increase IGF-I levels in follicular fluid and IGF-I may functions as an important regulator of IGFBP-3 synthesis in follicular fluid, but IGFBP-3 is not likely to be under the direct control of GH in follicular fluid.


Assuntos
Feminino , Humanos , Proliferação de Células , Estradiol , Fertilização in vitro , Líquido Folicular , Hormônio Liberador de Gonadotropina , Hormônio do Crescimento , Infertilidade , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina , Fator de Crescimento Insulin-Like I , Ovário , Indução da Ovulação , Ovulação
3.
Korean Journal of Fertility and Sterility ; : 217-223, 1997.
Artigo em Coreano | WPRIM | ID: wpr-88107

RESUMO

This study was performed to determine if women with day 3 serum inhibin-B concentrations or = 45pg/ml, independant of day 3 FSH, E2 and patient age. From Jan 1996 to Dec 1996, 16 volunteers patients who underwent 25 IVF cycles with luteal phase GnRH agonist suppression and HMG stimulation were allocated to the study group. We evaluated day 3 serum inhibits-B, FSH, E2, peak E2, cancellation rate per initiated cycle (%) and clinical pregnancy rate per initiated cycle (%) according to the above two groups and independent of patient age, day 3 FSH, day 3 E2 and all of above combined. Women with day 3 serum inhibin-B > or =45pg/m1 demonstrated higher average day 3 inhibits-B level, clinical pregnancy rate per initiated cycle (20.3+/-2.5 pg/ml vs 80.9+/- 5.0pg/ml, p or =45pg/ml and age or =45pg/ml and day 3 FSH or =45pg/ml and day 3 E2 or =45pg/ml, age<40 year, day 3 FSH<15mIU/ml and day 3 E2<50pg/m1 demonstrated higher pregnancy rate per initiated cycle (30.0% vs 10.8%, p<0.05) and lower day 3 FSH level, cancellation rate per initiated cycle (6.8+/-0.6 mIU/ml vs 8.4+/-0.9 mIU/ml, p<0.05; 1.5% vs 7.8%, p<0.05). Therefore women with low day 3 serum inhibits-B concentrations demonstrate a poorer response to ovulation induction and are less likely to conceive a clinical pregnancy though ART relative to women with high day 3 inhibits-B and day 3 serum inhibin-B, in addition to a day 3 FSH, E2 and patient age, appears helpful in prediction in IVF-ET outcome.


Assuntos
Feminino , Humanos , Gravidez , Hormônio Liberador de Gonadotropina , Sistema Internacional de Unidades , Fase Luteal , Indução da Ovulação , Taxa de Gravidez , Técnicas de Reprodução Assistida , Voluntários
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA