• The Korean Journal of Physiology
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• v.24 no.1
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• pp.1-13
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• 1990

The effects of electrolytes, adenosine, ATP, 5-hydroxytryptamine (5-HT, serotonin) and ketanserin on the inhibitory junction potentials (IJPs) were investigated to clarify the interactions of these drugs with the neurotransmitters released from non-adrenergic, non-cholinergic nerves in the antrum of guinea-pig stomach. Electrical responses of antral circular muscle cells were recorded intracellularly using glass capillary microelectrode filled with 3 M KCI. All experiments were performed in Tris-buffered Tyrode soluition which was aerated with 100% $O_{2}$ and kept at $35^{\circ}C$. The results obtained were as follows: 1) Inhibitory junction potential (IJP) was recorded in antral strip, while excitatory junction potential (EJP) was recorded in fundic strip. 2) IJP recorded in antral strip was not influenced by atropine $(10^{-6}\;M)$ and guanethidine $(5{\times}10^{-6})$. 3) The amplitude of IJP increased in high $Ca^{2+}$ solution, while that of IJP decreased in high $Mg^{2+}$ solution or by $Ca^{2+}$ antagonist (verapamil). Apamin, $Ca^{2+}$-activated $K^{+}$ channel blocker blocked IJP completely. 4) ATP and adenosine decreased the amplitude of IJP. 5) 5-HT decreased the amplitude of IJP with no change of the amplitude of slow waves, while ketanserin (5-HT type 2 blocker) decreased the amplitude of slow waves markedly with no change in that of IJP. From the above results, the following conclusions could be made. 1) IJP recorded in antral strip is resulted from neurotransmitters released from non-adrenergic, non-cholinergic nerves. 2) An increase in the concentration of external $Ca^{2+}$ enhances the release of neurotransmitters from non-adrenergic, non-cholinergic nerves which activate the $Ca^{2+}$-dependent $K^{+}$ channel.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.1
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• pp.29-38
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• 2009

Statement of problem: A casting connection technique is widely used for repair, correction and addition to base metal framework. However, a casting connection technique may increase the risk of failure in clinical situations when high stresses exist. Purpose: The purpose of this study was to investigate the mechanical retentive groove design comparatively to increase the joint strength by using the three-dimensional finite element analysis model of a 3-unit fixed partial denture. Material and methods: Ten finite element models were constructed. (Model A: One retentive groove, Model B: Two retentive grooves, Model C: Three retentive grooves, Model D: Four retentive grooves, Model E: One horizontal groove and two vertical grooves, Model F: Two horizontal grooves and one vertical groove, Model G: One groove with the enlarged dimension, Model H: Two grooves with the enlarged dimension, Model I: One groove with the increased height, Model J: One groove with the increased width of base). The vertical force was applied to the mesial and the distal fossa to the casting connection of mandibular first molar. Results: The main factors, affecting joint strength of casting connection were both the retention between the primary cast and the secondary cast and the thickness of the primary cast remaining after preparing retentive groove. The increase of retentive force, according to the numbers and the dimension of retentive groove had an effect on distributing stress. However, in some cases, the increase of retentive force resulted in the increase of stress by reducing thickness of the primary cast in the connection area. Conclusion: The design of retentive groove that limits number of retentive groove for metal thickness and increases the depth of retentive groove for retention is highly recommended.

• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.336-341
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• 2000

This study was conducted to clarify the habitat characteristics and distribution of seagrass. Zostera marina L. (Zosteraceae) in the brackish Hwajinpo Lake, Korea in June 1998 and July 2000. Z. marina beds were distributed along the sea-side cost of the lower lake mouth at 0.8 to 1.5m in death, and the seagrass bed area was about 3,200 m$^{2}$. Salinity, water temperature and pH were in the range of 8.0${\sim}$23.0$%_{o}$, 22.0${\sim}$23.7$^{\circ}C$ and 8.34${\sim}$8.62, respectively. Nutrient concentrations were generally now (TN: 24.34 ${\mu}$M, NH$_{4}$-N: 2.57 ${\mu}$M, NO$_{3}$-N: 0.56 ${\mu}$M, NO$_{2}$-N: 0.27 ${\mu}$M, TP: 2.08 ${\mu}$M, PO$_{4}$-P: 0.34 ${\mu}$M). Suspended particulate matters (SPM) concentration averaged 62.8 mg/l and particulate organic matter (POM) averaged 21.3 mg/l. Organic content of SPM averaged 33.9%. The beds substratum was composed of well-sorted, fine sand and its mean brain size was 3.13${\Phi}$. The Z. marina vegetation was almost submerged, and the morphological characteristics can be classified as steno-leaf phenotype by the shoot length, leaf width, and number of leaf vein. Shoot length and leaf width were 70.0${\sim}$126.5 cm and 5${\sim}$7 mm, respectively. Shoot densities ranged from 264 to 296/m$^{2}$, and the plants biomass was estimated at 332.6 to 373.0 g dw/m$^{2}$. Therefore, the habitats of Z. marina in Korea were recognized in a brackish lake, and morphological characteristics appeared to be variable.

• 한국해양학회지
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• v.28 no.3
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• pp.212-228
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• 1993

A chenier, about 860 m long, 30 to 60 m wide and 0.6∼1.6 m high, occurs on the upper muddy tidal flat in the Gomso bay, western coast of Korea, It consists of medium to fine sands and shells with small amounts of subangular gravels. Vertical sections across the chenier show gently landward dipping stratifications which include small-scale cross-bedded sets. the most probable source of the chenier is considered to be the intertidal sandy sediments. Vibracores taken along a line transversing the tidal flat reveal that the intertidal sand deposits are more than 5 m thick near the low-water line and become thinner toward the chenier. The most sand deposits are undertrain by tidal muds which occur behind the chenier as salt marsh deposits. C-14 age dating suggests that the sand deposits and the chenier are younger than about 1,800 years B.P. The chenier has originated from the intertidal sand shoals at the lower to mid sand flat, and has continuously moved landward. A series of aerial photographs (1967∼1989) reveal that intertidal sand shoals (predecessor of the western part of chenier) on the mid flat have continuously moved landward during the past two decades and ultimately attached to the eastern part of the chenier already anchored at the present position in the late 1960s. Repeated measurements (four times between 1991 and 1992) of morphological changes of the chenier indicate that the eastern two thirds of the chenier, mostly above the mean high water, has rarely moved whereas the western remainder below the mean high water, has moved continuously at a rate of 0.5 m/mo during the last two years (1991∼1992). This displacement rate has been considerably accelerated up to 1.0 m/mo in winter, and during a few days of typhoon in the summer of 1992 the displacement amounted to about 8∼11 m/mo for the entire chenier. these facts suggest that macro-tidal currents, coupled with winter-storm waves and infrequent strong typhoons, should play a major role for the formation and migration of chenier after 1,800 B.P., when the sea level already rose to the present position and thereafter remained constant.

• Journal of the Korean Wood Science and Technology
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• v.38 no.3
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• pp.199-204
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• 2010

Members used for the Korean traditional joints have been processed by handicraft, especially with domestic red pine species. Dovetail joint is most commonly used in woodworking joinery and traditional horizontal and vertical connections. It is able to be processed much easier to cut by handicraft and machines. However, although it is processed straight forwards, it requires a high degree of accuracy to ensure a snug fit. Also, tenons and mortises must fit together with no gap between them so that the joint interlocks tightly. A few scientific studies on the dovetail joints have been conducted so far. For the effective applications of traditional joints and domestic plantation wood species, dovetail joints were assembled by larch glulam members processed by machine pre-cut. To identify the tensile properties of through dovetail joints, larch glulam with 150 150mm in cross section were prepared. Furthermore, various geometric parameters of dovetai joints such as width, length, and tenon angle, were surveyed. The ends in the mortise was cracked mainly at a low strength level in the control specimens without reinforcements. The maximum tensile strengths of reinforced specimens considering real connections such as capital joint and headpiece on a column, increasedby handicraft, especially with domestic red pine species. Dovetail joint is most commonly used in woodworking joinery and traditional horizontal and vertical connections. It is able to be processed much easier to cut by handicraft and machines. However, although it is processed straight forwards, it requires a high degree of accuracy to ensure a snug fit. Also, tenons and mortises must fit together with no gap between them so that the joint interlocks tightly. A few scientific studies on the dovetail joints have been conducted so far. For the effective applications of traditional joints and domestic plantation wood species, dovetail joints were assembled by larch glulam members processed by machine pre-cut. To identify the tensile properties of through dovetail joints, larch glulam with 150 150mm in cross section were prepared. Furthermore, various geometric parameters of dovetai joints such as width, length, and tenon angle, were surveyed. The ends in the mortise was cracked mainly at a low strength level in the control specimens without reinforcements. The maximum tensile strengths of reinforced specimens considering real connections such as capital joint and headpiece on a column, increased by two times with shear failures on the tenon than the control specimens. The maximum tensile strength was obtained in the specimen of 25 degrees, and no difference was observed in the changes of neck widths.

• Journal of the Korean Arthroscopy Society
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• v.7 no.2
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• pp.201-205
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• 2003

Purpose : Authors experienced cases of chronic ACL tear with spur-like lesion on the tibial condyle which is different from the lateral capsular sign and degenerative change and evaluated the significance of 'spur-like lesion' in relations with chronic ACL injury. Material and Method : We have 5 patients with spur-like lesion on the lateral tibial condyle in simple radiogram. The location, shape and size of the lesion were studied using radiogram and MRI. Cause of injury, associated injury and chronicity of the ACL tear were analyzed. All 5 patients were male, and mean age was 33.8 $(17\~46)$ years. Result : The spur-like lesion was located from 3.8 mm(avg.) below the articular surface of the lateral tibial condyle to the apex of the fibular head and protruded laterally or inferolaterally from just posterior to the Gerdy's tubercle with a round or sharp-end triangular shape. Average length was 6 mm and average width ortho base was 9.2 mm. The cause of injury were sports jnjury 4 cases and traffic accident in one. The chronicity of the ACL tear was average 10.7(8 months$\~$23 years) years and medial meniscus tear was shown in all cases and lateral meniscus tear in three. Conclusion : We suggest that a patient who has a history of trauma with spur-like lesion on the lateral tibial condyle of the knee is expected to have chronic ACL tear.

• Journal of the Mineralogical Society of Korea
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• v.28 no.3
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• pp.255-263
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• 2015

To investigate the effect of the weathering process of biotite on Cs sorption, sorption experiment of Cs with $10^{-3}M$ solution was carried out on the biotite reacted at different reaction times at pH 2 and 4, and 1 M solutions of Na, K, Ca, Mg, Rb, and Cs. Peak changes were observed for some samples by XRD, indicating that new mineral phase formed by biotite weathering. Among several factors, cations in solutions have the most significant influence on the mineralogical changes. The samples reacted with Na showed the most outstanding change with increasing peak width and appearance of $12{\AA}$ peak and $14{\AA}$ peak. This new peaks indicate the formation of hydrobiotite and vermiculite. The new peaks had stronger peak intensity for the sample reacted at pH 4 than that at pH 2, probably due to the fast dissolution of small particles and edges and resultant decrease in the formation of expandable layers. The biotite reacted at Mg solution showed small intensity at $14{\AA}$. Based on XRD results, the degree of biotite weathering was in the order of Na, Mg, and Ca. The samples reacted with K, Rb, Cs solutions did not show noticeable mineralogical changes caused by weathering. The amount of sorbed Cs on weathered biotite showed close relationship with the degree of weathering indicated by XRD. At both pH 2 and 4, the biotite reacted with Na solution showed the highest Cs sorption, and those with Mg and Ca solutions showed the next highest ones. The sorbed amounts of Cs on the bitote reacted with K, Rb, Cs solutions were relatively low. This indicates that at the Cs concentration ($10^{-3}M$) which we used for this experiment and which was much higher than the maximum Cs concentration sorbed on the frayed edge site, expandable layer plays more important role than frayed edge. In the cases of K, Rb, and Cs solutions, Cs sorption was decreased because K is the same cations as the one in the interlayer or the sorption of Rb and Cs on the frayed edge prevents the formation of expandable layers.

• Journal of the Korean Society of Radiology
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• v.10 no.8
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• pp.603-610
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• 2016

This study was performed to analyze the results of radiologic parameters compared both leg weight bearing position to single leg weight bearing position in ankle osteoarthritis. Between January 2016 and June 2016, 25 patients (50 ankles) who visited our Hospital to treat ankle pain. In radiographic assessment, We masured tibial anterior surface angle(TAS), tibial medial malleolar angle(TMM), talar tilting angle(TT), joint space width(JSW), tibiotalar joint space, fibulotalar joint space of ankle as radiologic parameters. On the right leg of the both leg weight bearing position, TAS was $87.24^{\circ}$, TT was $6.44^{\circ}$, TMM was $26.76^{\circ}$, fibulotalar joint space was 0.98mm. Right leg of the single leg weight bearing position, TAS was $88.93^{\circ}$, TT was $2.41^{\circ}$, TMM was $19.77^{\circ}$, fibulotalar joint space was 1.6mm. And then, on the left leg of the both leg weight bearing position, TAS was $87.25^{\circ}$, TT was $5.71^{\circ}$, TMM was $23.92^{\circ}$, fibulotalar joint space was 1.22 mm and left leg of the single weight bearing position, TAS was 88.75, TT was $3.19^{\circ}$, TMM $21.45^{\circ}$, fibulotalar joint space was 1.22 mm. There are unsimilarity between measure values of TAS and tibiotalar joint space. As the result of test of weight bearing ankle study, it would be more exact to examine to measure one side in the first time rather than both to conclude on accurate measurement.

• Journal of the Korean Society of Radiology
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• v.11 no.1
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• pp.9-17
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• 2017

A high degree of precision and accuracy in Gamma Knife Radiosurgery(GKRS) is a fundamental requirement for therapeutical success. Elaborate radiation delivery and dose gradients with the steep fall-off of radiation are clinically applied thus necessitating a dedicated Quality Assurance(QA) program in order to guarantee dosimetric and geometric accuracy and reduce all the risk factors that can occur in GKRS. In this study, as a part of QA we verified the accuracy of single-shot dose profiles used in the algorithm of Gamma Knife Perfexion(PFX) treatment planning system employing Variable Ellipsoid Modeling Technique(VEMT). We evaluated the dose distributions of single-shots in a spherical ABC phantom with diameter 160 mm on Gamma Knife PFX. The single-shots were directed to the center of ABC phantom. Collimating configurations of 4, 8, and 16 mm sizes along x, y, and z axes were studied. Gamma Knife PFX treatment planning system being used in GKRS is called Leksell GammaPlan(LGP) ver 10.1.1. From the verification like this, the accuracy of GKRS will be doubled. Then the clinical application must be finally performed based on precision and accuracy of GKRS. Specifically the width at the 50% isodose level, that is, Full-Width-of-Half-Maximum(FWHM) was verified under such conditions that a patient's head is simulated as a sphere with diameter 160mm. All the data about dose profiles along x, y, and z axes predicted through VEMT were excellently consistent with dose profiles from LGP within specifications(${\leq}1mm$ at 50% isodose level) except for a little difference of FWHM and PENUMBRA(isodose level: 20%~80%) along z axis for 4 mm and 8mm collimating configurations. The maximum discrepancy of FWHM was less than 2.3% at all collimating configurations. The maximum discrepancy of PENUMBRA was given for the 8 mm collimator along z axis. The difference of FWHM and PENUMBRA in the dose distributions obtained with VEMT and LGP is too small to give the clinical significance in GKRS. The results of this study are considered as a reference for medical physicists involved in GKRS in the whole world. Therefore we can work to confirm the validity of dose distributions for all collimating configurations determined through the regular preventative maintenance program using the independent verification method VEMT for the results of LGP and clinically assure the perfect treatment for patients of GKRS. Thus the use of VEMT is expected that it will be a part of QA that can verify and operate the system safely.

• Childhood Kidney Diseases
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• v.16 no.2
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• pp.115-120
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• 2012

Purpose: We aimed to evaluate the efficacy of Octyl-2-cyanoacrylate (Dermabond$^{TM}$) as a topical skin adhesive for pediatric urologic open surgery. Methods: From August 2010 to August 2011, we retrospectively evaluated pediatric patients who underwent urologic open surgery at our institution. A total of 128 pediatric patients with 210 incisions used Dermabond$^{TM}$ for skin closure. Results: We divided the 128 patients into 3 groups according to type of surgery. Group 1 underwent hydrocelectomy (55 cases, 41.3%), Group 2 underwent orchiopexy (43 cases, 32.3%), Group 3 underwent penoplasty (35 cases, 26.4%). One hundred and twenty eight patients who underwent 133 surgeries in total, with a total of 210 incisions visited our outpatient department postoperatively, and a total of 5 wound complications (2.3%) occurred, but were simple inflammations and no dehiscence was observed. When analyzed according to groups, no wound problems occurred in Group 1 (0/55, 0%), one occurred in Group 2 (1/43, 2.3%) and four cases occurred in Group 3 (4/35, 11.4%) respectively. When re-analyzed according to wound locations, one occurred in an inguinal wound (1/120, 0.83%), none occurred in scrotal wounds (0/55, 0%), and four occurred in penile wounds (4/35, 11.4%). In Group 3, the incidence of penile wounds was significantly increased compared to other groups (P=0.008). All 5 wound problems were inflammatory and healed at an average of 13.8 days (13-15 days) with antibiotic ointment application only. Conclusion: Dermabond$^{TM}$ is feasible and safe topical skin adhesive alternative to standard skin suture in pediatric urologic surgery. However, further research about its efficacy and safety could be valuable in the future.