RESUMO
The present paper reports the results of a pragmatic prospective trial in a group of 38 random infertile couples in whom a battery of semen assays were performed before in vitro fertilisation (IVF). Sixteen couples (42.1%) attained ongoing pregnancy. Using logistic regression analysis only the result of the Oxisperm® (Pâ¯=â¯0.047) and the HaloSperm G2® for DNA fragmentation (Pâ¯<â¯0.0001) were significantly associated with the occurrence of pregnancy, whereas neither the conventional semen characteristics, nor the outcome of multiple other tests were significantly related (Pâ¯>â¯0.05). Based on the logistic regression analysis the following formula could be derived: Logit(p)â¯=â¯6.15-0.407â¯×â¯(% halotest), whereby (p) is the probability of pregnancy, and % halotest is the proportion of spermatozoa showing DNA fragmentation in the HaloSperm G2® test. Receiver operating characteristic curve analysis revealed an area under the curve (AUC) of 0.83. In 16 out of 38 couples the IVF outcome, either positive or negative, could unequivocally be predicted, while in the remaining cases the probability of pregnancy was significantly related to the result of the formula. These findings confirm the hypothesis that sperm DNA-fragmentation largely determines the success of IVF.
Assuntos
Fragmentação do DNA , Fertilização in vitro/métodos , Análise do Sêmen/métodos , Espermatozoides/fisiologia , Adulto , Área Sob a Curva , DNA/análise , Feminino , Humanos , Masculino , Modelos Teóricos , Gravidez , Resultado da Gravidez , Estudos Prospectivos , Curva ROC , Espécies Reativas de Oxigênio/metabolismo , Análise de Regressão , Adulto JovemRESUMO
The first results of the Dynamic Ergodic Divertor in TEXTOR, when operating in the m/n=3/1 mode configuration, are presented. The deeply penetrating external magnetic field perturbation of this configuration increases the toroidal plasma rotation. Staying below the excitation threshold for the m/n=2/1 tearing mode, this toroidal rotation is always in the direction of the plasma current, even if the toroidal projection of the rotating magnetic field perturbation is in the opposite direction. The observed toroidal rotation direction is consistent with a radial electric field, generated by an enhanced electron transport in the ergodic layers near the resonances of the perturbation. This is an effect different from theoretical predictions, which assume a direct coupling between rotating perturbation and plasma to be the dominant effect of momentum transfer.