• Communications of the Korean Mathematical Society
• /
• v.3 no.1
• /
• pp.51-58
• /
• 1988

• Clinical and Experimental Reproductive Medicine
• /
• v.21 no.1
• /
• pp.21-29
• /
• 1994

Subzonal insemination(SUZI) has been proposed for patients with severe male factor and previous fertilization failure. However, very low fertilization rates still persisted. The aims of this study were firstly, to examine the relationships between the fertilization rate and sperm parmeters, sperm incubation media and time, secondly, to evaluate the outcome of 119 cycles of SUZI applied the modified sperm preparation method. The fertilization rates were influenced more sensitively by sperm preincubation media and time than by sperm parameters. According to preincubation media and time, the fertilization rates were 43.3% in 50% follicular fluid (HFF), 36.6% in 10% fetal cord serum(FCS), and with the time, increased in FCS, but decreased in HFF. In regrd with sperm parameters, the fertilization rates were 42.9% in normal and 37.6% in subnormal group. The best results were obtained from SUZI by the spermatozoa incubated in 50% HFF for 6-8 hours. So we tried 119 cycles of SUZI(normal; 39 cycles, subnormal; 80 cycles) using the preparation method of 6-8 hour incubation in 50% HFF. There were no signigicant differences in the fertilization rates between normal(125/269, 46.4%) and subnormal sperm(264/635, 41.6%). Contrary to the fertilization rates, pregnancy outcomes were different between both groups. Better results obtained from the subnormal group than the normal in the number of transferred embryos, that of good embryos, and developmental rate of the fertilized eggs. The pregnancy rates per transfer were totally 13.3%(13/98),20.0%(13/65) in subnormal group. In the normal group, 2 patients showed ${\beta}$-hCG positive, but resulted in chemical pregnancy. Of 13 clinical pregnancies, two aborted, 6 on-going, and 5 delivered. In conclusion, SUZI is an effective technique to overcome fertilization failure for male factor and unexplained. The fertilization rate is influenced by sperm parameters, sperm incubation media and time. Also the quality of oocytes might be important for pregnancy as same as that of sperm.

• Journal of Nutrition and Health
• /
• v.29 no.1
• /
• pp.104-111
• /
• 1996

This study was carried out to determine the folate status of adolescent girls. Serum and red blood cell(RBC) folate levels of 132 Korean adolescent girls aged 12 to 15 years were evaluated by micorbioligical assay using Lactobacillus casei(ATCC 7469). Serum folate concentrations were less than 3ng/ml in 4.5% and 3 to 4.9ng/ml in 42.4%. Of the RBC folate values, 4.5% were less than 120ng/ml and 40.2% were 120 to 159ng/ml. These findings demonstrated that serum folate levels were subnormal in 46.9% and RBC folate levels were subnormal in 44.7% of the adolescent girls. Serum and RBC folate concentration tend to be high in folate supplemented subjects. There was no significant difference in serum and RBC folate levels, hemoglobin, and hematocrit values between regular meal group and irregular meal group.

• Kyungpook Mathematical Journal
• /
• v.55 no.2
• /
• pp.345-353
• /
• 2015

Subnormality of bounded weighted composition operators on $L^2({\Sigma})$ of the form $Wf=uf{\circ}T$, where T is a nonsingular measurable transformation on the underlying space X of a ${\sigma}$-finite measure space (X, ${\Sigma}$, ${\mu}$) and u is a weight function on X; is studied. The standard moment sequence characterizations of subnormality of weighted composition operators are given. It is shown that weighted composition operators are subnormal if and only if $\{J_n(x)\}^{+{\infty}}_{n=0}$ is a moment sequence for almost every $x{{\in}}X$, where $J_n=h_nE_n({\mid}u{\mid}^2){\circ}T^{-n}$, $h_n=d{\mu}{\circ}T^{-n}/d{\mu}$ and $E_n$ is the conditional expectation operator with respect to $T^{-n}{\Sigma}$.

• Journal of the Chungcheong Mathematical Society
• /
• v.27 no.1
• /
• pp.99-103
• /
• 2014

In this paper, we characterize the m-isometric weighted shifts, using this characterization, we study the relations between the hyponormality and the m-isometricity of operators.

• Korean Journal of Mathematics
• /
• v.20 no.4
• /
• pp.485-491
• /
• 2012

In this paper, we show the norm attaining paranormal operators have a nontrivial invariant subspace. Also, we show the norm attaining quadratically hyponormal weighted shift is subnormal.

• Clinical and Experimental Reproductive Medicine
• /
• v.21 no.3
• /
• pp.261-266
• /
• 1994

Semen preparation for Assisted Reproductive Technology(ART) involves the separation of the motile sperm from non-motile, dead sperm, cellular debris and seminal fluid. The aim of this study is to compare the motile sperm recovery rate and motility index of different sperm preparation method(swim-up method, 80% isotonic continuous percoll method, two-layer discontinuous percoll method, mini-percoll method). In Mini-Percoll method, pellets from patients were suspended in 0.3ml of medium and layerd on a discontinuous percoll gradient consisting of 0.3ml each of 50, 70, 95% isotonic percoll. All semen samples are divided into normal and subnormal sperm group(oligo-, astheno-, oligoasthenozoospermia). Especially, we evaluated the effect of mini-percoll method in subnormal sperm group. In normal sperm group, mini-percoll method and two layer discontinuous percoll method (40%/80%) allowed increasing of motile sperm recovery rate. But motility index was higher in swimup method than the other methods. In subnormal sperm group, mini-percoll method has advantages as compare with the other methods in motile sperm recovery rate and motility index. These results suggest that modified mini-percoll method could be certainly a valuable tool in some cases of severe male factor sperm.

• Journal of the Korean Mathematical Society
• /
• v.38 no.6
• /
• pp.1157-1166
• /
• 2001

This paper answers some old questions about approximate similarity and raises new ones. We provide positive evidence and a technique for finding negative evidence on the question of whether approximate similarity is the equivalence relation generated by approximate equivalence and similarity.

• Journal of the Chungcheong Mathematical Society
• /
• v.23 no.1
• /
• pp.163-168
• /
• 2010

In this paper it is shown that if [$T^*$,T] is of rank one and ker [$T^*$,T] is invariant for T, then T is quasinormal. Thus, we can know that the hyponormal condition is superfluous in the Morrel's theorem.

• Journal of the Chungcheong Mathematical Society
• /
• v.31 no.3
• /
• pp.325-331
• /
• 2018

In this paper, we study which transform preserves the k-hyponormality of weighted shifts. For this, we introduce a new transform, the modulus multiplication transform, and then examine various properties of it.