• Journal of Dental Rehabilitation and Applied Science
• /
• v.27 no.2
• /
• pp.125-140
• /
• 2011

The remnant of temporary cement on the intaglio surface of cast restoration may have a negative effect on the retentive strength of permanent cement. This study was to evaluate the effect of temporary cement cleaning methods on the retentive strength of cementation type implant prostheses. Prefabricated implant abutments - height 5.5mm, diameter 4.5mm, 6 degree axial wall taper with chamfer margins were used. Forty copings-abutment specimens were divided into four groups(each n=10) according to the cleaning methods for temporary cement(Temp-$Bond^{(R)}$) as follows : no temporary cementation(the control group), orange solvent, ultrasonic cleaning, air borne-particle abrasion. After the application of temporary cement and the separation, the cleaning procedure was performed according to the protocol of each group. The specimens were cemented with $Premier^{(R)}$ Implant $Cement^{TM}$. After the permanent cementation, the specimens were subjected to thermocycling and pulled out from the specimens with a universal testing machine at a cross-head speed of 0.5mm/min. After the retentive strength test, all the specimens were cleaned using ultrasonic cleaning, abraded with air borne-particles, and steam-cleaned. Likewise, the specimens were temporarily cemented(Temp-$Bond^{(R)}$ NE), cleaned according to the protocol of each group, cemented with $Premier^{(R)}$ Implant $Cement^{TM}$ and subjected to thermocycling and measurement of their retentive strength. The mean of group with orange solvent were significantly lower than those of other groups(p<0.05). There was no significance between group with ultrasonic cleaning and group with air borne-particle abrasion. Group with ultrasonic cleaning and group with air-particle abrasion were no significance at control group. There was no significance between group cemented with Temp-$Bond^{(R)}$ and group cemented with Temp-$Bond^{(R)}$ NE. Within the limitation of this study, it can be concluded that the temporary cement cleaning method with only orange solvent may have a negative effect on the retentive strength of permanent cement. Ultrasonic cleaning and air borne-particle abrasion methods are recommended for the temporary cement cleaning method on cementation type implant prostheses.

• Clinical and Experimental Reproductive Medicine
• /
• v.24 no.3
• /
• pp.311-318
• /
• 1997

Bypassing acrosome reaction and fusion process in intracytoplasmic sperm injection(ICSI), most of injected spermatozoa still contain intact acrosome contents and plasma membrane. It Is not known yet what acrosome contents and plasma membrane of spermatozoa have effect on the development of embryo. For further understanding of fertilization process after ICSI, we studied the time of pronucleus formation, disappearance and first cleavage in human zygote, and pregnancy rate in relation to acrosome reaction rate of spermatozoa after ICSI. Seventy cycles undergoing ICSI program were randomly selected. Sperm suspension from 38 cycles were treated 50% human follicular fluid(hFF) for 3 hours in order to induce acrosome reaction, others were not treated as control. Acrosome reaction in hFF treated and non-treated group was assessed by fluorescein isothiocyanate(FITC)-conjugated Arachis hypogea(PNA) and Pisum sativum agglutinin(PSA). Oocytes were classified into 'good' and 'poor' according to their morphology. After ICSI, fertilization of oocytes were assessed by detection of two pronuclei at 16 hours. The pronuclei disappearance and first cleavage of zygotes were observed at 24 hours, and then embryos were transferred to uterus after culture for 72 hours. The rate of acrosome reaction of spermatozoa in hFF treated group was significantly higher than that in control(p<0.01). Fertilization rates of good oocytes were not different both control and hFF treated group(81.3%(174/206) vs. 72.1%(102/130)). But, in poor oocytes, the fertilization rates in hFF treated group(72.1%(149/183)) were increased compared than those of control group (63.6%(98/140), p<0.01). In either good or poor oocytes, the rates of pronuclei disappearance in hFF treated-spermatozoa injected oocytes were higher than control (59.1%(103/174), 56.4%(84/149) vs. 32.4%(33/102), 37.8%(37/98), p<0.01). Also, the rates of thirst cleavage were increased in hFF treated group (31%(54/174), 24.1%(36/149)) compared than those of control group (10.8%(11/102), 13.2%(13/98), p<0.01). The pregnancy rates of hFF treated group (42.1%(16/38)) were slightly higher than control group (28.1%(9/32), p>0.05). But, the pregnancy rate of group which possessed more than one cleavaged zygote at 24 hours was higher than group which did not (45.2%(19/42) vs. 21.4%(6/28), p<0.05). From these results, the development of zygotes were faster in higher acrosome reacted sperm group than lower acrosome reacted sperm group after ICSI. Our results may be explained that acrosomal membrane and plasma membrane are easily detached from spermatozoa in acrosome reacted spermatozoa compared with acrosome intact sperm in the cytoplasm of oocyte during pronuclear formation. We conclude that the injection of acrosome reacted spermatozoa will increase the pregnancy rate as they can induce fast embryonic development in ICSI.

• Clinical and Experimental Reproductive Medicine
• /
• v.34 no.2
• /
• pp.87-94
• /
• 2007

Objective: To examine determinants of successful pregnancy and evaluate COH-IVF outcomes of infertile patients after conservative surgical treatment of borderline ovarian tumor (BOT). Methods: In women of BOT (n=93), from January 1995 to December 1999, 44 of 93 women underwent conservative surgical treatment. From theses 44 women, patients characteristics, surgical and histological parameters were compared between 14 women who conceived and 30 women who failed to conceive. For 5 infertile women of 30 women who failed to conceive, 10 attempt IVF cycles were analysed; clinical pregnancy rate (CPR), implantation rate (IR) and live birth rate (LBR). Results: Women who conceived tend to be younger (25.9 vs 27.0 years) and lower serum CA-125 level (59.7 vs 72.9) compared to women who failed to conceive without significant difference. For 8 cycles out of 10 attempt IVF cycles, except for 2 cancellation cycles, the mean number of oocytes retrieved was 5.6 (range 2$\sim$16) with a mean fertilization rate of 74.4%. The CPR, IR and LBR per embryo transfer were 50.0% (4/8 cycles), 31.6% (6/19) and 50.0% (4/8 cycles) respectively. During the mean follow-up period after COH-IVF initiation, 29.6 (range 14$\sim$61) months, no recurrence was found. Conclusion: No determinant of successful pregnancy was found after conservative treatment for BOT. COH-IVF may be considered for infertile patients after conservative treatment of BOT. However, larger clinical studies with longer follow-up are necessary to evaluate the safety and efficacy of COH-IVF. All patients should be informed of the potential risks associated with ovarian hyperstimulation and close follow-up is necessary after COH-IVF.

• Asian Journal of Turfgrass Science
• /
• v.1 no.1
• /
• pp.7-17
• /
• 1987

The experiment with two levels of nitrogen (0. and 300kg / ha / year) and two levels of clipping height (1.5cm and 4cm) was conducted on the field during the period 3 June to 23 October 1985. Clonal lines of korean lawngrass ( Zoysia japonica Steud.) and manilagrass ( Zoysia matrella ( L.) Merr.)of Daejon origin were established in June, as individual clone in rows 30cm apart with a 40cm spacing between clones, actually 4 clones each plot. The results obtained were as follows : 1. When no nitrogen was applied to korean lawngrass, leaf blade which appeared during the August / early September period remained green for a period of about 10 weeks and even leaves emerged in late September lived for 42 days. However, leaf longevity did not exceed 8 weeks as nitrogen was applied. In contrast the leaf longevity of manilagrass which emerged during the mid - August / early September period was 11 weeks and, under the nitrogen applied, 9 weeks, indicating that the life - saen of individual leaf of manilagrass may be longer than that of korean lawngrass. Meanwhile, clipping height had no effect on the leaf longevity in both grasses. 2. During the July / August period, tiller number, green leaf number and DM weight of korean lawngrass were increased significantly with fertilizer nitrogen, but were not with two levels of clipping height. This trend was reversed after late September : no effect of nitrogen was appeared. Instead, lax clipping increased tiller number, green leaf number and DM weight. Green leaves stimulated by lax clipping resulted in the occurrance of more dead leaves in late October. 3. The increase of tiller number, green leaf number, and DM weight of korean lawngrass due to nitrogen application appeared to be of significance in early September. Unlike korean lawngrass, however, this significant increase was maintained to late October when new green leaves still emerge. Clipping height had little effect on the growth of manilagrass by early September, but since then, lax clipping stimulated leaf appearance, possibly resulting in a remained green color of manilagrass turf. 4. Among the stolons outgrown until early September, the primary stolon was not influenced by nitrogen and clipping treatments to produce only 2 - 3 stolons. However, 1st branch stolon as affected by nitrogen increased significantly, so most of stolons which occurred consisted of 1st branch stolon. 5. Until early September, stolon length obtained at nil nitrogen level was chiefly caused by lengthening the primary stolons. By applying nitrogen the primary stolons of korean lawngrass was longer than 1st branch stolons when severe clipping was involved and in turn, shorter than 1st branch stolons when lax clipping was concerned. In manilagrass, 1st branch stolons were much longer than the primary stolons when turf was clipped severely but in conditions of lax clipping, there was little difference in length between primary and 1st branch stolons. 6. Stolon nodes of both korean lawngrass and manilagrass were positively influenced by nitrogen, but no particular increases by imposing clipping height treatment was marked in manilagrass. Although the stolon of korean lawngrass was grown until late october, the growth stimulated by nitrogen was not so remarkable as to exceed that a by nil N. 7. The thickness of korean lawngrass and manilagrass was greatest in late September, but that of manilagrass did not differ significantly from that in late October. 8. The response of stolon length of korean lawngrass to lax clippings was not so great in late October as to that to severe clippings. On the other hand, the positive effect of lax clippings to stolon length in m anilagrass was confirmed even in late October.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.20 no.5
• /
• pp.491-503
• /
• 2014

This study was performed to investigate the community structure and health assessment of macrobenthic assemblages in Garorim Bay, West Coast of Korea. Macrobenthos were collected by van Veen grab sampler at May(spring) and July(summer) 2012. A total of 247 species occurred and mean density was $1,625\;ind.\;m^{-2}$, both of which were dominated by annelid polychaetes(120 species and $1,241m^{-2}$). Dominant species were the polychaetes Ampharete arctica, Lumbrineris longifolia, Mediomastus californiensis and Euclymene oerstedi, with a density of 445(${\pm}1,837\;ind.\;m^{-2}$), 103(${\pm}148\;ind.\;m^{-2}$), 55(${\pm}83\;ind.\;m^{-2}$) and 50(${\pm}104\;ind.\;m^{-2}$), respectively. The study area was divided into 3 station group based on the cluster analysis and nMDS ordination. These assemblage were : 1)the group 1 and 2 were associated with coarse sediment dominated stations and 2)the group 3 was connected with a mixed and fine sediment dominated stations group. The BPI and AMBI index were applied to assess the benthic ecological status. The ecological status of the Garorim Bay was "good status(slightly polluted)" to "high status(normal)" at most sampling stations during spring and summer. In conclusion, the two marine biotic index calculated shown that the Garorim Bay had a good ecological status.

• Proceedings of the Korea Society for Simulation Conference
• /
• 1996.05a
• /
• pp.1-3
• /
• 1996

시뮬레이션 기법을 이용한 시스템의 분석에 있어서 실험의 자동화는 현재 많은 연구와 개발이 진행 중인 분야이다. 컴퓨터와 정보통신 시스템에 대한 시뮬레이션의 예를 들어 보면, 수많은 모델을 대한 시뮬레이션을 수행할 경우 자동화된 실험의 제어가 요구되고 있다. 시뮬레이션 수행회수, 수행길이, 데이터 수집방법 등과 관련하여 시뮬레이션 실험방법이 자동화가 되지 않으면, 시뮬레이션 실험에 필요한 시간과 인적 자원이 상당히 커지게 되며 출력데이터에 대한 분석에 있어서도 어려움이 따르게 된다. 시뮬레이션 실험방법을 자동화하면서 효율적인 시뮬레이션 출력분석을 위해서는 시뮬레이션을 수행하는 경우에 항상 발생하는 초기편의 (initial bias)를 제거하는 문제가 선결되어야 한다. 시뮬레이션 출력분석에 사용되는 데이터들이 초기편의를 반영하지 않는 안정상태에서 수집된 것이어야만 실제 시스템에 대한 올바른 해석이 가능하다. 실제로 시뮬레이션 출력분석과 관련하여 가장 중요하면서도 어려운 문제는 시뮬레이션의 출력데이터가 이루는 추계적 과정 (stochastic process)의 안정상태 평균과 이 평균에 대한 신뢰구간(confidence interval: c. i.)을 구하는 것이다. 한 신뢰구간에 포함되어 있는 정보는 의사결정자에게 얼마나 정확하게 평균을 추정할 구 있는지 알려 준다. 그러나, 신뢰구간을 구성하는 일은 하나의 시뮬레이션으로부터 얻어진 출력데이터가 일반적으로 비정체상태(nonstationary)이고 자동상관(autocorrelated)되어 있기 때문에, 전통적인 통계적인 기법을 직접적으로 이용할 수 없다. 이러한 문제를 해결하기 위해 시뮬레이션 출력데이터 분석기법이 사용된다.본 논문에서는 초기편의를 제거하기 위해서 필요한 출력데이터의 제거시점을 찾는 새로운 기법으로, 유클리드 거리(Euclidean distance: ED)를 이용한 방법과 현재 패턴 분류(pattern classification) 문제에 널리 사용 중인 역전파 신경망(backpropagation neural networks: BNN) 알고리듬을 이용하는 방법을 제시한다. 이 기법들은 대다수의 기존의 기법과는 달리 시험수행(pilot run)이 필요 없으며, 시뮬레이션의 단일수행(single run) 중에 제거시점을 결정할 수 있다. 제거시점과 관련된 기존 연구는 다음과 같다. 콘웨이방법은 현재의 데이터가 이후 데이터의 최대값이나 최소값이 아니면 이 데이터를 제거시점으로 결정하는데, 알고기듬 구조상 온라인으로 제거시점 결정이 불가능하다. 콘웨이방법이 알고리듬의 성격상 온라인이 불가능한 반면, 수정콘웨이방법 (Modified Conway Rule: MCR)은 현재의 데이터가 이전 데이터와 비교했을 때 최대값이나 최소값이 아닌 경우 현재의 데이터를 제거시점으로 결정하기 때문에 온라인이 가능하다. 평균교차방법(Crossings-of-the-Mean Rule: CMR)은 누적평균을 이용하면서 이 평균을 중심으로 관측치가 위에서 아래로, 또는 아래서 위로 교차하는 회수로 결정한다. 이 기법을 사용하려면 교차회수를 결정해야 하는데, 일반적으로 결정된 교차회수가 시스템에 상관없이 일반적으로 적용가능하지 않다는 문제점이 있다. 누적평균방법(Cumulative-Mean Rule: CMR2)은 여러 번의 시험수행을 통해서 얻어진 출력데이터에 대한 총누적평균(grand cumulative mean)을 그래프로 그린 다음, 안정상태인 점을 육안으로 결정한다. 이 방법은 여러 번의 시뮬레이션을 수행에서 얻어진 데이터들의 평균들에 대한 누적평균을 사용하기 매문에 온라인 제거시점 결정이 불가능하며, 작업자가 그래프를 보고 임의로 결정해야 하는 단점이 있다. Welch방법(Welch's Method: WM)은 브라운 브리지(Brownian bridge) 통계량()을 사용하는데, n이 무한에 가까워질 때, 이 브라운 브리지 분포(Brownian bridge distribution)에 수렴하는 성질을 이용한다. 시뮬레이션 출력데이터를 가지고 배치를 구성한 후 하나의 배치를 표본으로 사용한다. 이 기법은 알고리듬이 복잡하고, 값을 추정해야 하는 단점이 있다. Law-Kelton방법(Law-Kelton's Method: LKM)은 회귀 (regression)이론에 기초하는데, 시뮬레이션이 종료된 후 누적평균데이터에 대해서 회귀직선을 적합(fitting)시킨다. 회귀직선의 기울기가 0이라는 귀무가설이 채택되면 그 시점을 제거시점으로 결정한다. 일단 시뮬레이션이 종료된 다음, 데이터가 모아진 순서의 반대 순서로 데이터를 이용하기 때문에 온라인이 불가능하다. Welch절차(Welch's Procedure: WP)는 5회이상의 시뮬레이션수행을 통해 수집한 데이터의 이동평균을 이용해서 시각적으로 제거시점을 결정해야 하며, 반복제거방법을 사용해야 하기 때문에 온라인 제거시점의 결정이 불가능하다. 또한, 한번에 이동할 데이터의 크기(window size)를 결정해야 한다. 지금까지 알아 본 것처럼, 기존의 방법들은 시뮬레이션의 단일 수행 중의 온라인 제거시점 결정의 관점에서는 미약한 면이 있다. 또한, 현재의 시뮬레이션 상용소프트웨어는 작업자로 하여금 제거시점을 임의로 결정하도록 하기 때문에, 실험중인 시스템에 대해서 정확하고도 정량적으로 제거시점을 결정할 수 없게 되어 있다. 사용자가 임의로 제거시점을 결정하게 되면, 초기편의 문제를 효과적으로 해결하기 어려울 뿐만 아니라, 필요 이상으로 너무 많은 양을 제거하거나 초기편의를 해결하지 못할 만큼 너무 적은 양을 제거할 가능성이 커지게 된다. 또한, 기존의 방법들의 대부분은 제거시점을 찾기 위해서 시험수행이 필요하다. 즉, 안정상태 시점만을 찾기 위한 시뮬레이션 수행이 필요하며, 이렇게 사용된 시뮬레이션은 출력분석에 사용되지 않기 때문에 시간적인 손실이 크게 된다.

• Proceedings of the KOR-BRONCHOESO Conference
• /
• 1983.05a
• /
• pp.9.2-9
• /
• 1983

We have observed 74 cases of radiolucent foreign bodies in food and air passage in E. N. T. department of Hang Gang Sacred Hospital, from Jan. 1972 to Mar. 1983. The following results were obtained. 1) Distribution of location was 56 cases(75.6 %) in food passage and 18 cases (24.4 %) in air passage. 2) In age distribution, 46 cases (82.1 %) of F. B. in food passage were found in patient over 21 years old and 12 cases (66.7 %) of F. B. in air passage were found in patient under 5 years old. 3) Female seems to be more frequently involved than male in cases of F. B. of food passage and in cases of air passage, male is more frequent. Food passage male: female - - - 25 : 31 Air passage male: female - - - 10 : 8 4) Meats was the most frequent foreign body in food passage (19 cases-33.9%), and the bony pieces was next (17 cases-30.4 %). Plastic material was the most frequent foreign body in air passage (9 cases-49.9 %), and the vegetable seed was the second (4cases-22.0 %). 5) In the location of F. B. in food passage, the first narrowing of the esophagus was the most frequent site and in air passage, the bronchus-especially right bronchus-was the most frequent site. 6) In the duration of lodgement, 44 cases(78.6 %) of F.B. in food passage were visited with - in 24 hours, and 11 cases (61 %) of F. B. in air passage were visited with - in 24 hours. 7) Simple chest PA was checked in all patient and then, esophagogram was checked in 34 cases of F.B. in food passage, among them positive finding was noticed in 23 cases. 8) Removal of F. B. in food passage by esophagoscopy was performed in 54 cases (96.4 %), but in the cases of air passage, removal of F. B. by bronchoscopy was performed in 14 cases (77.8 %). 9) Complications of food passage by the F. B. itself or esophagoscopy were esophageal mucosal laceration (1 cases-1.8 %) and esophageal perforation (1 case -1. 8 %) and complication of air passage by F. B. itself or bronchoscopy were atelectasis (2 cases -11.1 %) and pneumonia (3 cases-16.7 %).

• Journal of the Korean Magnetics Society
• /
• v.5 no.4
• /
• pp.269-274
• /
• 1995

The basic composition of Mn-Zn ferrite was $Mn_{0.631}Zn_{0.316}Fe_{2.053}O_{4}$(specimen A), $Mn_{0.584}Zn_{0.312}Fe_{2.104}O_{4}$(specimen B) and $Mn_{0.538}Zn_{0.308}Fe_{2.154}O_{4}$(specimen C) with additional 0.1 mol % $CaCo_{3}$ and 0.04 mol % $V_{2}O_{5}$. For high per¬meability and acceleration of grain growth, $CaCo_{3}$ and $V_{2}O_{5}$. was added. The mixture of the law materials was calcinated at $950^{\circ}C$ for 3 hours and then milled. The compacts of toroidal type were sintered at different temperature($1250^{\circ}C$, $1300^{\circ}C$, $1350^{\circ}C$) for 2 hours in $N_2$ atmosphere. The effects of the various raw material composition and sintered temperature on the physical properties of Mn-Zn ferrite have been investigated. They turned out to be spinel structure by X-ray diffraction and the size of grain from SEM was from $18\;\mu\textrm{m}\;to\;23\;\mu\textrm{m}$. As the sintering temperature was increased from $1250^{\circ}C$ to $1350^{\circ}C$, the initial permeability and magnetic induction has increased and the both of Q factor and coercive force has decreased. The coercive force and curie temperature were almost the same at each specimen Their values were about 0.45 Oe and $200^{\circ}C$. The frequency of specimen will used in the range from 200 kHz to 2 MHz. The basic composition of $Mn_{0.584}Zn_{0.312}Fe_{2.104}O_{4}$(specimen B) sintered at $1300^{\circ}C$ shows the best results at magnetic induction (Br & Bm).

• Food Science and Preservation
• /
• v.24 no.1
• /
• pp.27-35
• /
• 2017

Microbiological, physicochemical, and organoleptic properties of fresh-cut vegetables (FVs), carrots, green peppers, cherry tomatoes, and paprika after X-ray irradiation were evaluated to verify food quality suitable for the immune-depressed patients. Total concentrations of aerobic bacteria in non-irradiated samples, except for cherry tomatoes, were 1.63-3.34 log CFU/g. Irradiation dose exceed 0.4 kGy was used for carrots and green peppers whereas the sterilization dose of 0.2 kGy was used for both cherry tomatoes and paprika. A dose of 0.4 kGy was tentatively determined as the minimum allowable dose for sterilization of the FVs, based on $D_{10}$-values of X-ray irradiation (0.11-0.32 kGy) for Escherichia coli, Listeria monocytogenes, and Salmonella Typhimurium inoculated on the samples. With respect to the physiological properties, only hardness was significantly decreased as the absorbed dose increased; however, there were no significant differences in hardness of the sterilized samples using X-rays at 0.4 kGy compared with those of non-irradiated samples (p<0.05). Moreover, overall acceptance scores of the sterilized FVs were higher than 5.0 points on a 7-point scale, indicating a good organoleptic quality. In a survey on preference of hospitalized patients with cancer (n=50), the average scores for the sterilized FVs, except for carrots, were higher than 4.0 points. In conclusion, it is considered that the FVs, except for carrots, sterilized using X-rays at 0.4 kGy could be served to immune-depressed patients as hygienically safe foods with acceptable organoleptic properties.

• Korean Journal of Food Science and Technology
• /
• v.17 no.5
• /
• pp.389-398
• /
• 1985

To shorten the processing of cheese slurry, four different slurries, ie, Control, Cheddar 1 and 2, and Italian-type that were made of Na-caseinates, cream, trace elements, lactic culture, and enzymes were fermented at $30^{\circ}C$ for 7days with daily stirring. PH, titratable acidity, soluble nitrogen, viable cell count, active SH groups, total volatile fatty acid, free fatty acid, electrophoretic patterns of degraded caseins, and viscosity were analyzed to investigate physicochemical properties of fermented slurries. Acid production was accelerated in the cheese slurries with protease than that without the enzyme and PH of the former was decreased after three days of fermentation to 4.90. The Change of titratable acidity agreed to PH patterns. Soluble nitrogen of the Control slurry was increased slowly for four days and then rapidly to 40% of total nitrogen while those containing protease to 70%. The protease of lactic cultures used (Streptococcus lactis and Streptococcus cremoris) broke down as-casein more rapidly than $\beta$-casein and most proteins were degraded to peptides and amino acids after three days of fermentation. Total volatile fatty acids were increased by added lipase and free fatty acids composition analyzed by GLC in cheddar slurry with 0.00001% lipase was similar to that of commercial cheddar cheese, while that in Italian-type slurry was a half of that in commercial Italian cheese. Active SH groups were increased in the cheese slurries with glutathione from fourth day of fermentation. The viscosity of slurries decreased very rapidly by addition of protease.