• Toxicological Research
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• v.16 no.3
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• pp.229-238
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• 2000

The purpose of reproductive toxicity studies is to evaluate all effects resulting from paternal or maternal exposure that interfere with conception, development, birth, and maturation of offspring. In 1966, the US Food and Drug Administration (US FDA) published guidelines for a three-segment study for drug testing to examine adverse effects on fertility and pregnancy. Three segments were proposed: Segment I, Study of Fertility and General Reproductive Performance, to provide information on breeding, fertility, nidation, parturition, neonatal effects and lactation: Segment II, Teratological study, to provide information on embryo toxicity and teratogenicity: and Segment III. perinatal and Postnatal Study, to provide information on late fetal development, labour and delivery, neonatal viability, and growth and lactation. The classic guideline is still used to this day with only monor modification throughout the world. In the present review, the principles and methods of reproductive toxicity studies are discussed with special attention given to scientific issues.

• The korean journal of orthodontics
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• v.49 no.6
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• pp.393-403
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• 2019

Objective: Sliding mechanics using orthodontic miniscrews is widely used to stabilize the anchorage during extraction space closure. However, previous studies have reported that both posterior segment displacement and anterior segment displacement are possible, depending on the mechanical properties of the archwire. The present study aimed to investigate the effect of archwire stiffness and friction change on the displacement pattern of the maxillary posterior segment during anterior segment retraction with orthodontic miniscrews in sliding mechanics. Methods: A three-dimensional finite element model was constructed. The retraction point was set at the archwire level between the lateral incisor and canine, and the orthodontic miniscrew was located at a height of 8 mm from the archwire between the second premolar and first molar. Archwire stiffness was simulated with rectangular stainless steel wires and a rigid body was used as a control. Various friction levels were set for the surface contact model. Displacement patterns for the posterior and anterior segments were compared between the conditions. Results: Both the anterior and posterior segments exhibited backward rotation, regardless of archwire stiffness or friction. Among the conditions tested in this study, the least undesirable rotation was found with low archwire stiffness and low friction. Conclusions: Posterior segment displacement may be unavoidable but reducing the stiffness and friction of the main archwire may minimize unwanted rotations during extraction space closure.

• Phonetics and Speech Sciences
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• v.1 no.3
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• pp.65-72
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• 2009

Formant values are the most important acoustic correlates of English vowels. Classical studies on English vowels reported the first three formant values measured at a single timepoint on a sustained vowel segment. However, many recent studies revealed that partial onset or offset segments with information of dynamic spectral changes may contribute to the exact identification of English vowels with an accuracy almost comparable to that by the whole vowel segment or word. The purpose of this study was to examine formant trajectories of nine English vowels collected by Hillenbrand et al.(1995). Acoustic analysis was systematically made by a Praat script at six equidistant timepoints over the vowel segment. Results showed that the first formant trajectories played an important role in distinguishing each vowel within the front- or back-vowel groups. The second formant trajectories of the back vowels varied more drastically than those of the front vowels. The third formant value was similar except the high vowel /i/. From the vowel space on F1 by F2 axes, the formant trajectories of each vowel clearly showed a transition toward the locus of the following consonant /d/. Other acoustic data revealed that there were some vowel inherent duration or pitch values. From this study we can conclude that the dynamic spectral changes are very important in specifying acoustic characteristics of the English vowels. Further studies on vowels and diphthongs in different contexts are desirable.

• MALSORI
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• no.43
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• pp.163-178
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• 2002

In this paper, we discuss the characteristics of Segmental-Feature HMM and summarize previous studies of SFHMM. There are several approaches to reduce the number of parameters in the previous studies. However, if the number of parameters decreased, the performance of systems also fell. Therefore, we consider the fast computation approach with preserving the same number of parameters. In this paper, we present the new segment comparison method to speed up the computation of SFHMM without loss of performance. The proposed method uses the three-frame calculation rather than the full(five) frames in the given segment. The experimental results show that the performance of the proposed system is better than that of the previous studies.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.14 no.2
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• pp.135-146
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• 2019

Objectives : There are many theories about the anatomical relationships between the thoracic spinous and transverse processes. However, these studies were all conducted on cadavers. Thus, there might be differences when applied to living individuals. Therefore, the aim of this study was to determine whether the theories were similar when measured in living individuals. Methods : We conducted studies with 10 individuals aged 20-30 using 3D-CT. Four different measurements were taken between the thoracic spinous and transverse processes. To facilitate the relationship analysis, the spinous process positioned between the traverse process of the segment and the lower segment was set to 0.5. The spinous process located at the height of the traverse process of the lower segment was set to 1. The spinous process located between the traverse process of the lower segment and the two segments below was set to 1.5. Results : Therefore, based on the aforementioned settings, T1-T4 were 1, T5-T7 were 1.5, T8-T10 were 1, and T11 and T12 were 0.5. This indicated that the spinous processes of T1-T4 and T8-T10 were equal in height to the transverse processes of the lower segment, and that T5-T7 were at the midpoint of the height of the transverse processes between the lower segment and two segments below, and T11, T12 corresponded to the midpoint between the traverse process of the segment and the lower segment. Conclusions : Neither 'Geelhoed's rule'nor 'the rule of three'was accurate when applied to living individuals. However, this study had some limitations, so further research is needed.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.4
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• pp.200-217
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• 2023

The purpose of this study is to analyze the urban spatial network of Busan in a time-series manner to examine the planning role of centeral area change and spatial management. The analysis method used the ASA(Angular Segment Analysis) technique of the space syntax theory, and the analysis period was divided into three periods from 1937 to 2022, when the Busan urban planning was established. As the result, the center area formed in Nampo-dong and Gwangbok-dong were differentiated and moved to Seomyeon, and then the process of redifferentiated into Yeonsan was confirmed in Seomyeon. It is also room for the center area to move to the western region in the future, and it was possible to identify the center area formed by the policy-set and amenity elements. In addition, we examined the system of urban spatial structure through the intelligibility analysis of space syntax theory, and found that the qualitative interpretation of existing studies and the interpretation from the perspective of space syntax theory were consistent with each other. Through this, it was possible to confirm that the role of the plan for space management.

• Korean Journal of Environmental Biology
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• v.25 no.1
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• pp.72-79
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• 2007

Mormonilla phasma is redescribed, based on the specimens from the Northeastern Pacific. M. phasma in the study area has the following morphological characteristics; second endopodal segment of mandible partly fused to basis and a distinct three-segmented exopod of mandible in anterior view and one indistinct segment in posterior view which are different from the description given by Boxshall (1979). In addition the first and the second endopodal segments of leg 1 were also separated indistinctly. Other morphological characteristics are similar to those reported in previous studies. The morphological anomalies in endopodal segments of the leg 1, unknown up to now are also discussed. This study is the first report on the distribution of M. phasma in the Northeastern Pacific.

• International Area Studies Review
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• v.13 no.2
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• pp.669-686
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• 2009

This study attempted to segment food festival market based on delineated motivation and find factors and find the difference attendants' characteristics among segment market. The study also explored the influence of motivation factors on satisfaction. The results shows that The results are followings : (1) Derived factors of food festival attendance motivation were 'food', 'escape', 'familey togetherness', 'entertainment'. (2) A cluster analysis identified three segments for four motivation factors. Three segments were found to be different according to age, income, the number of company, and information source. (3) Four motivation factors had significant influence on satisfaction. food factor's influence was the highest. and 'family togetherness', 'escape', 'entertainment' are ranked accordingly.

• Geomechanics and Engineering
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• v.37 no.6
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• pp.599-614
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• 2024

To evaluate the safety status of deteriorated segments in a submarine shield tunnel during its service life, a seepage model was established based on a cross-sea shield tunnel project. This model was used to study the migration patterns of erosive ions within the shield segments. Based on these laws, the degree of deterioration of the segments was determined. Using the derived analytical solution, the internal forces within the segments were calculated. Lastly, by applying the formula for calculating safety factors, the variation trends in the safety factors of segments with different degrees of deterioration were obtained. The findings demonstrate that corrosive seawater presents the evolution characteristics of continuous seepage from the outside to the inside of the tunnel. The nearby seepage field shows locally concentrated characteristics when there is leakage at the joint, which causes the seepage field's depth and scope to significantly increase. The chlorine ion content decreases gradually with the increase of the distance from the outer surface of the tunnel. The penetration of erosion ions in the segment is facilitated by the presence of water pressure. The ion content of the entire ring segment lining structure is related in the following order: vault < haunch < springing. The difference in the segment's rate of increase in chlorine ion content decreases as service time increases. Based on the analytical solution calculation, the segment's safety factor drops more when the joint leaks than when its intact, and the change rate between the two states exhibits a general downward trend. The safety factor shows a similar change rule at different water depths and continuously decreases at the same segment position as the water depth increases. The three phases of "sudden drop-rise-stability" are represented by a "spoon-shaped" change rule on the safety factor's change curve. The issue of the poor applicability of indicators in earlier studies is resolved by the analytical solution, which only requires determining the loss degree of the segment lining's effective bearing thickness to calculate the safety factor of any cross-section of the shield tunnel. The analytical solution's computation results, however, have some safety margins and are cautious. The process of establishing the evaluation model indicates that the secondary lining made of molded concrete can also have its safety status assessed using the analytical solution. It is very important for the safe operation of the tunnel and the safety of people's property and has a wide range of applications.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.18 no.2
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• pp.36-50
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• 2005

Background and Objectives: Allergic rhinitis is an allergic reaction characterized by sneezingm itchy nose, mouth and throat, congestion and/or nasal discharge. The offending allergenes are usually pollens, molds, dust mites and animal allergen. Recently, the incidence of infectious nasal diseases tend to decrease. However, allergic rhinitis has increased and treatment in most cases has only deat with the symptom. Tongkyu-tang was composed of sixteen crude drugs. The Oriental Medical References mention therapeutic effects of Tongkyu-tang on nasal obstruction, watery nasal discharg. And Tongkyu-tang has clinically been used for the treatment of common cold, headache, sternutation, rhinitis etc. Speacially Tongkyu-tang is one of the most frequently used medical treatment for the allergic rhinitis. Experimental studies were conducted to investigate for the effect of Tongkyu-tang on the changes of neutrophil segment, lymphocyte, total IgE and nassal tissue in allergic rhinitis of ovalbumin-inhalation rat. Meterial and Methods: Fifteen Sprague-Dawley rats were divided into three group: normal group, control group, experimental group. To induce the allergic rhinitis in control group and experimental group, rats were sentitized intraperitoneally with 0.1 % ovalbumin solution 3 times at intervals of I week. Then intranasal sensitization was performed by diffusing 0.1 % ovalbumin solution 3 times at intervals of 2 days. After that time, rat in the experimental group were oral administration treated by Tongkyu-tang for 28 days. We observed changes in nasal tissue; changes in the number of white blood cell, red blood cell and total Ig E; also changes in the segment of neutrophil and lymphocyte in blood. And we observed the changes of AST, ALT of three group. We used anova test statistically. Result: The number of leucocyte remained unchanged between three group. The number of erythrocyte was increased in experimental group and control group when compared with the normal group. The segment of neutrophil, in blood was decreased in experimental group when compared with the control group but, that was not significant statistically(p<0.05). The promotion of lymphocyte in blood was significantly decreased in experimental group when compared with the Control group(p<0.05). Total IgE was decreased in experimental group when compared with the control group but, that was not significant statistically(p<0.05). The cilium be well preserved in experimental group: the nasal tissue in experimental group was similar to in the normal group. Congestion and expantion of grandular cell in nasal submucosa, hypertropy of epithelium in nasal mucosa, acid mucus in epithelium and neutral mucus in subepithelium were decreased in experimental group when compared with the control group. Effect of Tongkyu-tang on the liver function were also studies in rats. Treatment of Tongkyu-lang did not affected on AST and ALT. Conclusion: Considering the above experimental results, it is suggested that oral administration treatment using Tongkyu-lang, without worry about liver function injury, decreased response on an Animal model with Allergic Rhinitis.