Microstructure and oxygen reduction reaction in PTFE-bonded PlatinumCarbon electrodes

학위논문(박사)--서울대학교 대학원 :무기재료공학과,1996.Docto

(The) Research of the Snaking Effect of Strip Shape Change in Mini mill Process

Maste

The Effect of Myleran on Developing Rat Fetuses

Sprague•Dawley strain rats were administered orally once with the d,,"e of Myleran 20mg/kg, body weight on the 6th , 7th 10th , 11th , 12th day of gestation and with the dose of Myleran 30mg/kg, body weight on the 9th , 10th , 11th , 13th day of gestation and with the dose of myleran 40mg/kg body weigh on the 9th , 11th, 12th, 13th day of gestation. Gross anomalies in the fetuses, weigh, length and breadth of the brain of the live fetuses, survival rate of fetuses, changes of fetal body weight, and numbers of corpus Iuteum of maternal ovaries, and crown rump length and transumbilical distance were studied after hysterectomy on the 21st day of gestation and the following results were obtained. 1. The gross anomalies were appeared only in the groups administered with the dose of myleran 40mg/kg body weight and those were short tail, growth retardation microcephalus, hydrocephalus, micromelia, growth retardation of the limb, abnormal number of digits, syndactyli, anophthalmia and edema. The abnormal tails were observed in the highest incidence throughout the anomalies appeared in the fetuses of experimental groups. Combined anomalies of micromelia, syndactylia and edema were charactaristic. The 9th day of gestation seemed to be the most susceptible to the effect of the administration of Myleran. 2. Significant change of fetal body weight came out in the result of the all groups treated with the administration of the Myleran, and in the later administration g' roups, the more obvious decrease of body the fetal weight were obscr 、' e d . 3. Weight of the brain occured little changes in the group which was administered with the dose of 20mg/kg body weight, but gradual decrease of the weight appeared in the other groups. And notable decrease resulted in the group which was aclminist• ered with the dose of 40mg/kg body weight 4. Ohvious reduction of the fetal brain took place in all groups. And the results 、，v c r c in proportion to the doses 5. Gradual reduction of the breadth of the brain was observed in proportion to the do~es and aceor• ding to the days of gestation treated \vith Mylcran. 6. Trans--umhilical distances were observed only in the group which administered with the dose of 40mg/kg body weight, and the reduction of the distance was gradual in acιordance with the date of administration 7. Crown-rump length \\o'as measured only in the groups of 40mg/kg body weight. No significant change of CRL was observed at the group which received administration of Myleran on the 9th day of gesta tion , but gradual reductions 、，y e r e occurred in the other groups. 8. Most obvious decrease of the survival rate was observed in the group of 40mg/kg body weight. Gradual decrease of the survival rate was in inverse accordance with days of gestation. 9. Numbers of the corpus luteum were not effected by the administration of the Myleran

Studies on Antibody Forming Cells:n. Autoradiographic study on the origin of plasma cells.

A development study of the plasma cells was performed on the spleen of the young adult rabbits, weighing from 1. 7 to 2. 0 Kg. , after a single injection of 1 ml. diphthelia toxoid (22 Lf/ ml. , from 5x recrystalized diphthelial toxin, ) intravenously. Control and injected animals both received intravenously O. 3μC of 3H-thymidine (specific activity 6.7 curies/mM) per gm. body weight on the 3rd day after the injection. Animals were sacrificed at various intervals(from 1st day to 14th day) and spleen of both groups (injected and control) stained with methyl-green pyronin were compared each other. One of the main changes found was in the periarterial lymphocyte sheath and perifollicular zone in the white pulp. An increase of large pyroninophilic cells labelled with 3H-thymidine was found in this area on the 3rd day after the injection of the antigen. On the 6th and 8th days, a decrease occurred in the proportion of these cells in this area, while some of the labelled plasma cell series were found in the junction of the red and white pulp. The other histological changes found were in the germinal center of the white pulp. An increase of the medium-sized lymphocytes and the large lymphocytes appeared in this area on the 6th day after the injection of the antigen and these cells were found incorporated with 3H-thymidine. And the changes of the germinal center persisted on the period during the subsequent 6th to 14th day. It suggests that the germinal center do not concern with the process of the antibody production and may playa role in the production of memory cells