• The korean journal of orthodontics
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• v.26 no.2 s.55
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• pp.153-162
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• 1996

Rapid maxillary expansion is widely used for the correction of anteroposterior discrepancies, constriction of the maxillary arch, etc. This experiment was undertaken to examine the serial changes in the osteogenesis as well as the collagen fiber bundles in the intermaxillary suture during the rapid maxillary expansion treatment. Four young female dogs aged 6 to 8 months old and not showing menarche yet were used for the experiment. The maxillary impression of dogs were taken, expansion device cast and Hyrax screw soldered at the midline in the 1st premolar area. RME device was delivered to the dogs and the activation of 0.25 mm per quarter-turn was done 2 times per day for 10 days until 5 mm separation was made. Separation of the maxilla was confirmed by X-ray. The animals were sacrificed on 0, 15, 30, 60 days from the finish of maxillary separation and preparations for light microscopy and surface electron microscopy were made. The sutures were cut into frontal serial sections for examination of the histological reactions. The following results were obtained and the conclusions made. 1. The edges of the two palatal plates bordering the midpalatal suture which at the beginning of the retention period were mainly composed of compact bone, underwent extensive resorption followed by new bone formation and gradually became spongy bone rich in bone marrow which in the 60 day retention animal became the compact bone with short intermaxillary suture space. During this transformation, newly formed trabecular bone tissues were added to the original margin. 2. Throughout the expansion period, the collagen fibers underwent successive changes such as stretching, loss of polarity, and finally fibrillogenesis. Towards the end of the expansion procedure, sharpey's fiber formation in newly formed bones were observed. 3. Bony spicules were found in the initial stage of retention on occlusal topographic X-rays, which later were confirmed to have ossified. 4. Judging from the histological changes occuring during the experimental expansion, excessive expansion will cause an excessive bleeding, and retard the remodeling of intermaxillary suture. According to the above results, the bone remodeling after rapid maxillary expansion was preceded by the migration of migratory cells into the intermaxillary suture area. The bone remodeling phenomena were on-going during the 2 months retention sample.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.326-332
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• 2011

The growth and bolting characteristics of spring Chinese cabbage cultivars at two night-time temperature treatments such as $5^{\circ}C$ and $10^{\circ}C$ during seedling stage were investigated to establish a safe environmental management strategy for raising seedlings. The low night-time temperature treatments were applied at 5, 10, and 15 days after sawing and the treatment durations were 5, 10, and 15 days in each of treatment beginning. The growth of seedlings in all the tested cultivars were linearly reduced as the treatment duration was extended and no symptoms of bolting were found. The reduction rate in seedling growth of 'Chunkwang' reached to 59.3% at most by 15 days of $5^{\circ}C$ treatment when it be compared to that of control. However, no symptoms of bolting were shown in the treatments of two night-time temperatures until the harvest at 90 days after sawing, indicating that the vernalization effect by low night-time temperature could be mitigated by subsequent day-time optimal temperature management. This study showed that the major spring Chinese cabbage cultivars require more ultimate level of low night-time temperature treatment for the vernalization than this study. It is also supposed that the optimal day-time temperature management can reduce or delay the rate of bolting, even if the seedlings were exposed to short-term low temperature below $5^{\circ}C$ during night-time.

• Korean journal of applied entomology
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• v.37 no.2
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• pp.143-149
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• 1998

Development and life table statistics of indian meal moth (Plodia interpunctella, Hiibner)on brown rice (Sativa oryzae L., var 'Ilpum' ) were tested under five different temperatures (17, 20, 25,28 and 3 2 f 0.5"C). The developmental response of females to the temperature was not significantlydifferent from that of males. In the tested temperature range, developmental period and life span of adultmoth decreased as the temperature increased and ranged from 149.9f30.4 to 38.1 k5.6 days and from19.4f 5.1 to 6.9k2.0 days at 17$^{\circ}$C and 32"C, respectively. Emergence rate increased with the increaseof temperature and ranged from 13.0f 6.2% at 17$^{\circ}$C to 49.2f 25.9% at 32$^{\circ}$C. However, hatching ratecurve in relation to the temperature was dome shape with the peak of 73.8 k5.37~a t 25"C, suggesting thathatching is inhibited by high temperature above that temperature. As the temperature increased, femalesconcentrated their oviposition on the second day after emergence. In the temperature range of 17 SIM 25"C, the number of eggs laid per female were not related to the temperature and ranged from 133.4f 37.6to 154.3k57.4. But the number of eggs laid per female decreased at 32$^{\circ}$C which suggests closerelationship with hatching ability. The net reproduction rate was highest at 28$^{\circ}$C and followed by those at25$^{\circ}$C and 20$^{\circ}$C. However intrinsic rate of natural increase of the moth population on brown rice wasestimated to be highest at 32$^{\circ}$C (0.065 per day), probably due to the short developmental period, highemergence rate and the concentrated oviposition of females on earlier days of the emergence.ition of females on earlier days of the emergence.

• Journal of agricultural medicine and community health
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• v.29 no.2
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• pp.303-314
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• 2004

Objectives: This study was carried out to assess exposure levels of organic dusts and ammonia in poultry farms in Korea. Methods: A total of six poultry farms were investigated. The farms were located in Namwon, Chonlabuk-do and in Kae-San, Chungchongbuk-do. This study consisted of a questionnaire and measuring organic dusts and ammonia. The questionnaire included the characteristics of the farms, work patterns and the tasks of the poultry farms. Results and Conclusions: The farmers raised the chickens 45 times a year and the average number of years in the poultry farm were eight years ranging from 2 to 12 years. They worked for seven days per week and the average hours spent caring the chickens are 6.3 hours per day. The duration of staying in the confinement buildings was 3.3 hours per day. The work time in summer was longest. The feed and the water supply systems were automatic and the control of ventilation windows used "winch curtain" was semiautomatic. They used mechanical ventilation system in winter and used dilution ventilation system in the other seasons. The geometric mean concentration of total and respirable dust sampled in the poultry confinement buildings was 4.0 mg/$m^3$and 0.9 mg/$m^3$ respectively. The ratio of respirable to total dusts range from 9 to 49 percent. There was no sample exceeding the criteria 10 mg/$m^3$ for total dust and 3 mg/$m^3$ for respirable dust in farms. The criteria have been recommended by Korean Ministry of Labor and American Conference of Governmental Industrial Hygienist. The personal respirable dusts measured during a circle work averaged geometric mean concentration 1.4 mg/$m^3$ Two personal samples were exceeded the threshold 3 mg/$m^3$. There was a positive relation between an index and the personal samples of respirable dusts($R^2$=0.98). The index is calculated by multipling the total number of chickens in the farm by the age of the chickens and then dividing by the volume of the confinement building. The geometric mean concentration of area and personal ammonia samples was 23.3 ppm and 22.2 ppm, respectively. Some of the ammonia samples, both area and personal samples, exceeded the short term exposure limit value 35 ppm.

• Korean Journal of Plant Resources
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• v.32 no.5
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• pp.509-518
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• 2019

This study was conducted to investigate single crossing condition of M. sacchariflrous and M. sinensis for breeding of M. ${\times}$ giganteus cultivar. Compared with natural day length condition, cultivation in short day length condition shorten days to heading to 18~27 days in both species. Pollen germination ratio of were 75.8% at 6 o'clock in M. sacchariflorus and 51.9% at 7 o'clock in M. sinensis but decreased to below 10% at 8 o'clock in both species. When cut ears immerged in 150 mL of cut-flowers conservation solution and isolated with covering of white non-woven fabric, flowering and pollen dispersal were persisted for 7 days, and the ratio of pollen germination were above 40% for 4 days. The ratio of self-fertilization of both species were below 2.5%, but open pollenation ratio were above 50%. We obtained 437 seeds with experimental single cross of 14 combinations between tetraploid M. sacchariflorus and diploid M. siensis by application of developed single crossing methods. In the single cross, numbers of seed set were different by mother plants. Thus, the newly investigated single crossing condition will be used to breed M. ${\times}$ giganteous cultivar which is sterile and has superior characteristics of biomass yield.

• Korean journal of applied entomology
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• v.59 no.4
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• pp.383-391
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• 2020

The vertical distribution and dispersion of the two-spotted spider mite, Tetranychus urticae and its predator, Phytoseiulus persimilis, were investigated within and between green pepper plants. We also tested the effect of an artificial bridge with threads on dispersal of P. persimilis between the plants. The extent of spread of T. urticae depended on its infested density and location. When 10 adults of T. urticae were inoculated on upper leaf, they stayed on the upper leaf until 5 days after inoculation. However, when 100 adults were inoculated on an upper leaf, they dispersed to the lower leaf within a day. In condition that 10 adults of T. urticae were inoculated on the lower leaf, they started to move toward upward within a day. In the absence of T. urticae, P. persimilis tended to move to the leaves where T. urticae was present when both T. urticae and P. persimilis were inoculated together within a plant. An artificial bridge with threads between two plants was helpful to disperse P. persimilis to neighboring plants. Therefore, it would be expected that the dispersal of P. persimilis can be promoted by supplying the artificial bridges among plants and by narrowing the distances between plants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.1
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• pp.76-83
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• 1984

This experiment was performed to investigate the flowering habit of sesame (Sesamum indicum L.). Sesame varieties tested could be classified into 8 different plant types by their morphological traits such as capsule shape, capsule setting habit and branching types among sesame gene pool of Crop Experiment Station, ORD. The first flower was appeared at the lowest node on main stem. Flowers were appeared progressively toward the tip of the main stem and also toward the tips of branches. The interval of flowering for a node was about one day, but 3 to 8 days for the flowers on the tips. Side flowers started at 4 to 5 nodes lower than those of center flower at the same day. Flowers were beared 2 by 1 node on the middle part of flower setting node (7-9) in mono capsule setting habit in spite of its normal is 1 by 1 node on the other nodes. Flowers were beared opposite direction on each node of stem and flowering toward the tip of main stem composed of cross shape between nodes and spiral, reverse of clockwise direction. We called this habit as cross spiral flowering order and cross spiral phyllotaxis. The first flower on branches was appeared when center flower on the 5th node of main stem began to flower. The branches produced at higher nodes on main stem showed larger flowering periods and more number of flowers than that at lower parts. BTB (Branch, Tricapsule, Bicarpels, 4 Loculi) type showed three capsule setting habits and same flowering period both on main stem and branches while BTQ (Branch, Tricapsule, Quadricarpels, 8 Loculi) type showed three capsule setting habit on main stem and mono-capsule setting habit on branches. In BTQ type, the period of flowering was much shorter on branches than on main stem. Branching type was considered more promising than non branching type for the breeding of early maturing high yielding variety because branching type has the advantage of bearing a lot of flowers in comparatively short flowering period.

• Parasites, Hosts and Diseases
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• v.28 no.4
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• pp.241-252
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• 1990

In a basic attempt to develop the prophylactic and therapeutic measures on intestinal giantcystic disease of the Israel carp, C), prinks carpio nudum, the effects of physical and chemical factors on viability or survival of the spores of Thelchcnellus kiteuei were checked in vitro by means of extrusion test on the polar filament. When the fresh spores suspended with 0.45% and 0.9% scdium chloride solution and distilled water were laid at $5^{\circ}C$ and $28^{\circ}C$ for short terms, the extrusion rates increased until the 3rd day, meanwhile when son;e of them were suspended with Tyrode's solution at $-70^{\circ}C$ the rates increased gradually until the 8th day. Viabilities of the spores suspended with 0.9% saline and added antibiotics to the suspension at $5^{\circ}C$ for long terms lasted for 997 days and 1, 256 days (presumed values) at maximum, respectively. The spores suspended with distilled water at $28^{\circ}C$ for long terms survived 152.4 days, but the spores suspended with Tyrode's solution at $-70^{\circ}C$ for long terms showed almost the same viable pattern as early freezing stages up to 780 days. The spores suspended with Tyrode's solution, frozen at $-70^{\circ}C$ and thawed at $5^{\circ}C$, showed the highest rate of extrusion of the polar filament. In the case of frozen spores, the extrusion rates during heating tend to become higher in accordance with the increase of frozen period, and the critical points of 180 day-frozen spores to be killed were generally 78.5 hr. at $60^{\circ}C$, 23.4 hr. at $70^{\circ}C$, 189.1 min. at $80^{\circ}C$ or 10.5 min. at $90^{\circ}C$. The longer the spores were frozen, the more time was needed for the death of spores after thawing; 20 days-17.4 days, 100 days-33.2 days, and 400 days-37.8 days. The longer the spores were frozen, the more time was needed for the death of spores at a conventional when they were dried air drying condition, 540 days-23.5 days, 160 days-21.0 days, and 20 days-14.4 days. On the other hand, the longer the spores were frozen, the more spores were dead rapidly when they were irradiated with 10W UV-ray; 100 days-26.0 hr, 300 days-21.9 hr, and 540 days-13.9 hr. The time needed for killing 200 days-frozen spores by various disinfectants at 1, 000 ppd was 5.2 min. by calcium oxide, 10.4 min. by potassium permanganate, 27.8 min. by malachite green and 14.3 hr. by formalin. Transient inhibitory effects of the extrusion of the polar filament were observed by various antiprotozoal and antifungal agents in the descending order of ketoconazole. metronidasole and dapsone. The above results presume that full drying, followed by spraying CaO and maintaining sunny condition for a few days on the concrete bottoms of knish farm may be an effective method for the prevention of intestinal giant.cystic disease.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.7 no.1
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• pp.31-39
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• 2004

Purpose: Although acute nonspecific mesenteric lymphadenitis (ANML) is probably common cause of abdominal pain in children, which can be severe enough to be an abdominal emergency, the clinical features of mesenteric lymphadenitis are not clear. Also, a differential diagnosis with acute appendicitis (APPE) is indispensable to avoid serious complications. The clinical features of ANML were determined, and the risk factors for differential diagnosis with APPE were analyzed. Methods: Between November 2000 and May 2001, data from 26 patients (aged 1 to 11 years) with ANML and 21 patients (aged 2 to 13 years) with APPE were reviewed. ANML was defined as a cluster of five or more lymph nodes measuring 10 mm or greater in their longitudinal diameter in the right lower quadrant (RLQ) without an identifiable specific inflammatory process on the ultrasonographic examination. There were risk factors on patient's history, physical examination, and laboratory examination; the location of abdominal pain, abdominal rigidity, rebound tenderness, fever, nocturnal pain, the vomiting intensity, the diarrhea intensity, the symptom duration, and the peripheral blood leukocytes count. Results: Of the 26 ANML patients and 21 APPE patients, abdominal pain was noted on periumbilical (76.9% vs 14.2%), on RLQ (11.5% vs 71.4%), with abdomen rigidity (7.6% vs 80.9%), with rebound tenderness (0.0% vs 76.1%)(p<0.05), in the lower abdomen (11.5% vs 14.2%), and at night (80.8% vs 100.0%) (p>0.05). The clinical symptoms were vomiting (38.4% vs 90.4%), the vomiting intensity ($1.5{\pm}0.7$ [1~3]/day vs $4.5{\pm}2.9$ [1~10]/day), diarrhea (65.3% vs 28.5%) (p<0.05), and fever (61.5% vs 76.2%)(p>0.05). The period to the subsidence of abdominal pain in the ANMA patients was $2.5{\pm}0.5$ (2~3) days. The laboratory data showed a significant difference in the peripheral blood leukocytes count ($8,403{\pm}1,737[5,900{\sim}12,300]/mm^3\;vs\;15,471{\pm}3,749[5,400{\sim}20,800]/mm^3$)(p<0.05). Discriminant analysis between ANML and APPE showed that the independent discriminant factors were a vomiting intensity and the peripheral blood leukocytes count and the discriminant power was 95.7%. Conclusion: The clinical characteristics of ANML were abrupt onset of periumbilical pain without rigidity or rebound tenderness, a mild vomiting intensity, normal peripheral leukocytes count, and relatively short clinical course. If the abdominal pain persist for more than 3 days, and/or the vomiting intensity is more than 3 times/day, and/or the peripheral leukocytes count is over $13,500/mm^3$, abdominal ultrasonography is recommended to rule out APPE.

• The Korean Journal of Nuclear Medicine
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• v.29 no.1
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• pp.31-40
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• 1995

We compared stress/rest myocardial Tc-99m-MIBl tomographic image findings with rest/stress rubidium-82 tomographic images. In 23 patients with coronary artery disease (12 of them received bypass grafts before) and 6 normal subjects, rest rubidium PET study was performed : rubidium-82 and Tc-99m-MIBI were injected simultaneously to each patient after dipyridamole stress for rubidium PET and MIBI SPECT; and rest MIBI SPECT was performed 4 hours thereafter. We scored segmental decrease of rubidium or MIBI uptakes into 5 grades for 29 segments from 3 short-axis, vertical and horizontal slices. Scores were summed for each major arterial territory. When more score than two grade-2's or one grade-3 was considered as the cue for significant stenosis for major arterial territories, 67% of 46 stenosed arteries were found with MIBI studies and 78% of them by rubidium studies. Fourteen among 28 grafted arterial territories of 12 post-CABG patients were found normal with both rubidium and MIBI. Segmental scores were concordant between rubidium and MIBI in 72% of 709 stress segments and in 80% of 825 rest segments. Stress rubidium segmental scores were less than stress MIBI scores in 9%, so were rest rubidium scores. Stress rubidium scores were more than stress MIBI scores in 20% of segments, and rest rubidium segmental scores were more than rest MIBl scores in 11%. Rank correlations (Spearman's rho's more than 0.7(stress) and 0.5(rest), slopes (MIBI/rubidium) around 0.7(stress) and 0.9 (rest)) suggested deeper and wider defects in stress with rubidium. Slope over 1 (MIBI/rubidium) with LAD segemental scores at rest and 7 territories which had much larger score with MIBI revealed exaggeration of rest defects with rest MIBI in same-day stress/rest study. Difference scores (stress-rest for each territory) suggesting Ischemia were larger with rubidium (slope of MIBI/rubidium around 0.45). As has been implied by animal or separate-day-human studies, these segmental analyses with simultaneous examination in patients told that rubidium PET flow studies disclose ischemia more often than MIBI studies and that rest MIBI studies in same-day stress/rest-sequence gave a little larger rest defect than they would have shown.