• The Journal of Korean Academy of Prosthodontics
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• v.46 no.2
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• pp.201-208
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• 2008

Statement of problem: A new implant impression technique which use abutments as impression coping, and use resin cement as a splinting material was described. Accuracy of this technique was compared with conventional closed tray and resin splinted open tray technique for a $15^{\circ}$ angled 3-implant model Material and methods: A dental stone master model with 3 linearly positioned implant analogue and a reference framework which was passively fitted to it were fabricated. The center analogue was perpendicular to the plane of model and the outer analogues had a $15^{\circ}$angulation forward or backward. 10 closed tray impressions, 10 resin splinted open tray impressions, 10 abutment-resin framework cementation impressions and 10 abutment-metal framework cementation impressions were made with additional silicone material and poured with dental stone. A light microscope with image processing was used to record the vertical gap dimension between reference framework and analogue of duplicated cast made with each 4 impression techniques. Statistical analysis used one-way ANOVA with post-hoc tests Tukey test of .05 level of significance Results: Significant difference in the vertical gap dimension was found between closed tray technique; 74.3 (${\pm}33.4$)${\mu}m$ and resin splinted open tray technique, and two other new technique. (P<.05) Abutment-metal framework cementation technique;42.5 (${\pm}11.9$)${\mu}m$ was significantly different from resin splinted open tray technique. (P<.05) Abutmentresin framework cementation technique;51.0 (${\pm}14.1$)${\mu}m$ did not differ significantly from resin splinted open tray technique;50.3 (${\pm}16.9$)${\mu}m$. (P>.05) Conclusion: Within limitations of this study, the accuracy of implant level impressions of resin splinted open tray technique was superior to that of closed tray technique. A new technique using abutment and metal framework cementation was more accurate than resin splinted open tray technique.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.3
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• pp.444-453
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• 2005

Sometimes the dentists encounter a child who can not be treated with traditional behavior management techniques (for example, reward, restraint, Tell-Show-Do, familialization). In such a case, the dentists use sedation technique. Recently, in Korea, the use of sedation by pediatric dentists is increased. But, the guideline and survey of sedation is very insufficient. Now, we need a survey of sedation practice in Korea. We carried out research on the actual condition about sedation with a questionaire to pediatric dentists in Korea. Followings are the conclusions 1. Sixty six percent of pediatric dentists use sedative agents in their practice. In this study, using sedation shows an increase as compared with the past. 2. Determinative factors of using sedation were orderly behavior management, number of visiting, guidian's opinion, amount of treatment, general condition. 3. Distribution of ages in patients sedated with agents was orderly 3 years, 4-5 years, under 2 years, 6-10 years, more than 10 years. 4. Particular sedative drugs were chloral hydrate 60-70mg/kg, hydroxyzine 10-40mg/kg(25mg/kg), and oral route was the most favorable route. 5. Observation of skin and nail color, pulse oximeter were the most frequently utillized monitoring method during sedation. 6. Only fifty six percent of pediatric dentists complete the cardiopulmonary resuscitation course.

• Journal of the Korean Chemical Society
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• v.33 no.1
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• pp.18-24
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• 1989

Two crystal structures of dehydrated $Ag^+$ and $Rb^+$ exchanged zeolite A, stoichiometries of $Ag_{9}Rb_{3}-A$ (a = 12.278(2)${\AA}$) and $Ag_{10}Rb_{2}-A$ (a = 12.286(2)${\AA}$) per unit cell, have been determined by single crystal x-ray diffraction techniques. Their structures were solved and refined in the cubic space group Pm3m at 21(1)$^{\circ}$C. The crystals of $Ag_{10}Rb_{2}-A$ and $Ag_{10}Rb_{2}-A$ were prepared by flow methods using exchanged solution in which mole ratios of AgNO$_3$ and RbNO$_3$ were 1:5 and 1:50, respectively, with the total concentration of 0.05 M. The structures of the dehydrated $Ag_{9}Rb_{3}-A$ and the $Ag_{10}Rb_{2}-A$ were refined to the final error indices, $R_1$ = 0.064 and $R_2$ = 0.060 with 291 reflections, and $R_1$ = 0.063 and $R_2$ = 0.080 with 416 reflections respectively, for which I >3${\sigma}$(I). In both structures, one reduced silver atom per unit cell was found inside the sodalite cavity. It may be present as a hexasilver cluster in 1/6 of the sodalite units or as an isolated Ag atom coordinated to 4 $Ag^+$ ions in each sodalite unit to give $(Ag_5)^{4+}$, symmetry 4 mm. In the structure of dehydrated $Ag_{9}Rb_{3}-A$, 8 $Ag^+$ ions lie on the threefold axis and each is nearly at the center of the 8-rings at the sites of $D_{4h}$ symmetry. In the structure of dehydrated $Ag_{10}Rb_{2}-A$, two crystallographically different eight 6-ring $Ag^+$ ions were found; $7Ag^+$ ions in the (111) planes of their O(3) framework oxygens and one $Ag^+$ ion inside of sodalite cavity. Two crystallographically different 8-ring cations were also found; two $Rb^+$ ions at the centers of the 8-oxygen rings and one $Ag^+$ ion into the large cavity. Both structures indicate that $Rb^+$ ions prefer to occupy the 8-ring sites, while $Ag^+$ ions prefer to occupy the 6-ring sites.

• Clinical and Experimental Reproductive Medicine
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• v.4 no.1
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• pp.17-25
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• 1977

Anderson(1937), Power and Barnes(1941) reported a study concerning a method of tubal sterilization in association with peritoneoscopy or laparoscopy in which they cauterized the tubes. There appears to have been a hiatus of interest in sterilization (cold or hot) associated with laparoscopy until reintroduction by Palmer(1963), Frangenheim(1964) and Steptoe(1967). On the other hand, for interval female sterilization, however, minilaparotomy is relatively new. By Saunder and Munsick(1972), John Lyle(1974), Frank Stubb(1974), Vitoon(1973) and B.C. Bai(1975), their own technique for interval female sterilization requires 2.0 to 2.5cm, incision at the margin of the mons pubis. In Korea, female sterilization by means of minilaparotomy firstly reported by B.C. Bai using Bai's uterine elevator, of his own device, early in 1975. Recently inteval female sterilization by laparoscopy and minilaparotomy are widely accepted throughout the world especially in Asian countries. Minilaparotomy is carried out from 1974, laparoscopic sterilization from 1976, and in this study each of 250 cases of those were analysed and discussed for the comparison at Seoul Red Cross Hospital. (1) In the age distribution, numerous clients were in their age of $31{\sim}35$ in laparoscopy as well as minilaparotomy. Average 33.7 years in L and 33.2 years in M. (M=minilaparotomy, L=laparoscopic sterilization) (2) As regarding living children, women having 3 children represented the greatest number, 113 cases out of 250 in M group and 102 cases out of 250 in L group. Average No. of child are 2.9 in Land 3.1 in M. (3) Concidering the operation day in the menstrml cycle, the greatest number of cases, those who underwent tubal sterilization during the days of $26{\sim}$, next during the $6{\sim}10$ days of the cycle in both group. (4) Concidering the operation time, 188 cases by laparoscopy were performed in $6{\sim}10$ minutes, 33 cases within 5 minutes and 24 cases in $11{\sim}15$ minutes. Maximum 50 minutes, minimum 4 minutes and average 8.3 minutes. The majority of cases (154 cases) by minilaparotomy required $6{\sim}10$ minutes and 67 cases $11{\sim}15$ minutes, 6 cases within 5 minutes. Maximum 30 minutes, minimum 4 minutes and average 10.4, minutes. In both groups, most of the reasons for the extra length were surgical difficulties such as thick abdominal wall, pelvic adhesion, less cooperation of patients in early period of this study. (5) Hospital stay after operation in L group required $3{\sim}4$ hours in 125 cases, $2{\sim}3$ hours in 41 cases, $4{\sim}5$ hours in 32 cases out of 250. Maximum 8 hours, minimum 1 hour and average 3.8 hours. In M group hospital stay required $6{\sim}7$ hours in 100 cases, over 7 hours in 85 cases, $5{\sim}6$ hours in 46 cases and so on. Maximum 14 hours, minimum 2 hours and average 6.5 hours. (6) The time between operation and gas passing in the majority cases of both groups, were $12{\sim}36$ hours. A veragetime 20.3 hours in L and 27.2 in M. (7) Laparoscopic sterilization coincident with induced abortion were carried out in 27 cases, laparoscopy with minilaparotomy to control for mesosalpingeal hemorrhage in 1 case. Minilaparotomy coincident with induced abortion were performed in 65 cases, D and C whit polypectomy, menstrual regulatian, and remaval of IUD in 1 case respectively. (8) In L group, 1 case of mesosalpingeal hemorrhage, 1 case of abdominal wall infection were complicated during operation. In M group, 1 case of uterine perfaration, 1 case of abdominal wall infection, 1 case of hemorrhage from omentum and 1 case of bloody vaginal discharge were complicated. No intensive medical treatment was required for those minor complications in both groups. (9) No failure has been recognized and these two sterilization techniques might be the simple, safe and the most effective method for permanent contraception at present time. There is no significant clinical defference between L and M group in this study.

• Geophysics and Geophysical Exploration
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• v.5 no.4
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• pp.280-290
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• 2002

Three-dimensional (3-D) electromagnetic (EM) modeling algorithm has been developed using finite element method (FEM) to acquire more efficient interpretation techniques of EM data. When FEM based on nodal elements is applied to EM problem, spurious solutions, so called 'vector parasite', are occurred due to the discontinuity of normal electric fields and may lead the completely erroneous results. Among the methods curing the spurious problem, this study adopts vector element of which basis function has the amplitude and direction. To reduce computational cost and required core memory, complex bi-conjugate gradient (CBCG) method is applied to solving complex symmetric matrix of FEM and point Jacobi method is used to accelerate convergence rate. To verify the developed 3-D EM modeling algorithm, its electric and magnetic field for a layered-earth model are compared with those of layered-earth solution. As we expected, the vector based FEM developed in this study does not cause ny vector parasite problem, while conventional nodal based FEM causes lots of errors due to the discontinuity of field variables. For testing the applicability to high frequencies 100 MHz is used as an operating frequency for the layer structure. Modeled fields calculated from developed code are also well matched with the layered-earth ones for a model with dielectric anomaly as well as conductive anomaly. In a vertical electric dipole source case, however, the discontinuity of field variables causes the conventional nodal based FEM to include a lot of errors due to the vector parasite. Even for the case, the vector based FEM gave almost the same results as the layered-earth solution. The magnetic fields induced by a dielectric anomaly at high frequencies show unique behaviors different from those by a conductive anomaly. Since our 3-D EM modeling code can reflect the effect from a dielectric anomaly as well as a conductive anomaly, it may be a groundwork not only to apply high frequency EM method to the field survey but also to analyze the fold data obtained by high frequency EM method.

• The Korean Journal of Zoology
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• v.23 no.2
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• pp.89-108
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• 1980

Comparative studies on the parafollicular cells of the some mammalian species from five different orders were carried out; i.e., man from Primates, cattle, pig, and black goat from Artiodactyla, dog from Carnivora, rabbit from Lagomorpha, rat, mouse, and squirrel from Rodentia. For this study, various special techniques for the parafollicular cells, including Grimelius' silver impregnation method (Sawicki and Bajko, 1974), Singh's argentaffin method (Singh, 1964), HCl-toluidine blue stain (Sawicki, 1971), and HCl-lead hematoxylin stain (Solcia et al., 1969), were applied. Authors obtained the following results: 1. Number of parafollicular cells in the same area of thyroid tissues are significantly different from species to species. Number of cells were largest in dog and less cells were found in the following orders; rat, squirrel, mouse, rabbit, cattle, pig, black goat and finally the smallest number in man. 2. Distribution of parafollicular cells within thyroid gland are significantly different from portion to portion in case of cattle, rabbit, squirrel and mouse, but it is not significant in dog, man, pig, black goat and rat (see Table 1-1 and 1-2). 3. In dog, clustered parafollicular cells are located usually in the interfollicular space, and groups of parafollicular cells are located in the para-and/or inter-follicular positions in rabbit. But in the other animals parafollicular cells are found solitarily in the intra-and/or para-follicular positions. 4. The shape of parafollicular cells shows oval to round contour in dog, but it is polymorphic, for example, spindle, conical, oval, round or elongated with cytoplasmic processes, in the other animals. 5. Size of parafollicular cells is larger in cattle, dog and pig, smaller in rat, mouse and squirrel, and medium-size in rabbit, man and black goat. 6. Parafollicular cells of pig, cattle, dog and squirrel are observed to contain densely packed granules, whereas those of mouse, rat and man contain relatively scanty granules. 7. Parafollicular cells of all the mammals show more or less positive reaction to Grimelius' argyrophile silver impregnation method, HCl-toluidine blue stain and HCl-lead hematoxylin stain, whereas they show negative reaction to argentaffin method (see Table 2). 8. Considering the above finding, it is concluded that there are species differences in the distribution, location and shape of parafollicular cells, and infer that preferable staining method should be selected for reliable detection of parafollicular cells, beacuse staining methods applied on the cells in this study show variable reactions according to species.

• Korean Journal of Food Science and Technology
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• v.44 no.6
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• pp.763-771
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• 2012

In this study, total antioxidant properties of extracts from different parts of Lespedeza bicolor were determined using techniques of measuring 1,1-diphenyl-2-picryl hydrazyl/2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)-radical scavenging activity and total phenolic contents. The total antioxidant activities of leaf, stem and root extracts from various solvents (water, 50, 70, 100% ethanol, and hot-water) indicated that 50 and 70% ethanol extracts have high radical scavenging activities and phenolic contents. A systematic approach was used to determine the total antioxidant activity of different solvent fractions of the Lespedeza bicolor extracts, partitioning with chloroform, ethyl acetate, n-butanol, and water, and the ethyl acetate fraction was found to have the strongest antioxidant activity. Antioxidant assay-guided isolation was carried out to isolate potential antioxidant compounds. The ethyl acetate fraction of the leaf extract was subjected to silica gel, LH-20 and RP-18 column chromatography successively, and afforded compound 1, which was identified as eriodictyol by NMR and MS analysis, after which its antioxidant activity was determined.

• Journal of Life Science
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• v.27 no.12
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• pp.1445-1451
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• 2017

Mitochondria play a central role in energy generation by using electron transport coupled with oxidative phosphorylation. They also participate in other important cellular functions including metabolism, apoptosis, signaling, and reactive oxygen species production. Therefore, mitochondrial dysfunction is known to contribute to a variety of human diseases. Furthermore, there are various inherited diseases of energy metabolism due to mitochondrial DNA (mtDNA) mutations. Unfortunately, therapeutic options for these inherited mtDNA diseases are extremely limited. In this regard, mitochondrial replacement techniques are taking on increased importance in developing a clinical approach to inherited mtDNA diseases. In this study, green fluorescence protein (GFP)-tagged mitochondria were isolated by differential centrifugation from a mammalian cell line. Using microinjection technique, the isolated GFP-tagged mitochondria were then transferred to bovine oocytes that were triggered for early development. During the early developmental period from bovine oocytes to blastocysts, the transferred mitochondria were observed using fluorescent microscopy. The microinjected mitochondria were dispersed rapidly into the cytoplasm of oocytes and were passed down to subsequent cells of 2-cell, 4-cell, 8-cell, morula, and blastocyst stages. Together, these results demonstrate a successful in vitro transfer of isolated mitochondria to oocytes and provide a model for mitochondrial replacement implicated in inherited mtDNA diseases and animal cloning.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.3
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• pp.219-226
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• 2014

Evaluation of tree responses to temperature elevation is critical for a development of forest management techniques coping with climate change. We conducted a study on the growth responses of Betula costata, Fraxinus rhynchophylla, and Quercus variabilis seedlings to open-field artificial warming. Artificial warming set-up using infra-red heater was built in 2012 and the temperature in warmed plots was regulated to be consistently $3^{\circ}C$ higher than that of control plots. The seeds of three species were sown, and the responses of growth, biomass allocation, and net photosynthetic rate of newly-germinated seedlings on the open-field artificial warming were determined. As a result, the growth responses of the seedlings differed with the species. B. costata showed decreases in the height to diameter ratio (H/D ratio), biomass, root weight to shoot weight ratio, and net photosynthetic rate. However, root collar diameter (RCD), height, biomass, and net photosynthetic rate of Q. variabilis were increased, while the response of F. rhynchophylla was rather obscure. There was no significant difference between warmed and control plots in seedling growth for 3 species in July, whereas, RCD, height, and H/D ratio of Q. variabilis were increased and H/D ratio of B. costata was decreased in November under warming. Species-specific growth responses to warming were similar to the species-specific responses of net photosynthetic rate and biomass allocation; therefore, net photosynthetic rate and biomass allocation might attribute to growth responses to warming. Besides, a relatively obvious response in autumn compared to summer might be affected by the phenological change following artificial warming. Species-specific responses of three deciduous species to warming in this study could be applied to the development of adaptive forest management policies to climate change.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.4
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• pp.233-241
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• 2016

Experiments were carried out to quantify the topographic effects on attenuation of sunshine in complex terrain and the results are expected to help convert the coarse resolution sunshine duration information provided by the Korea Meteorological Administration (KMA) into a detailed map reflecting the terrain characteristics of mountainous watershed. Hourly shaded relief images for one year, each pixel consisting of 0 to 255 brightness value, were constructed by applying techniques of shadow modeling and skyline analysis to the 3m resolution digital elevation model for an experimental watershed on the southern slope of Mt. Jiri in Korea. By using a bimetal sunshine recorder, sunshine duration was measured at three points with different terrain conditions in the watershed from May 15, 2015 to May 14, 2016. The brightness values of the 3 corresponding pixel points on the shaded relief map were extracted and regressed to the measured sunshine duration, resulting in a brightness-sunshine duration response curve for a clear day. We devised a method to calibrate this curve equation according to sky condition categorized by cloud amount and used it to derive an empirical model for estimating sunshine duration over a complex terrain. When the performance of this model was compared with a conventional scheme for estimating sunshine duration over a horizontal plane, the estimation bias was improved remarkably and the root mean square error for daily sunshine hour was 1.7hr, which is a reduction by 37% from the conventional method. In order to apply this model to a given area, the clear-sky sunshine duration of each pixel should be produced on hourly intervals first, by driving the curve equation with the hourly shaded relief image of the area. Next, the cloud effect is corrected by 3-hourly 'sky condition' of the KMA digital forecast products. Finally, daily sunshine hour can be obtained by accumulating the hourly sunshine duration. A detailed sunshine duration distribution of 3m horizontal resolution was obtained by applying this procedure to the experimental watershed.