• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.3
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• pp.381-390
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• 2004

The purpose of this in vitro study was to investigate the effects of Nd:YAG laser irradiation and fluorides on acid drink demineralized enamel. The materials were 30 freshly extracted permanent premolars with intact smooth enamel surfaces. They were demineralized with Coca-cola at $37^{\circ}C$ for 12hours and then irradiated by Nd:YAG laser with 6W power, $50mJ/cm^2$ energy density, and 20Hz pulse repetition. After laser irradiation, teeth were treated by three kinds of fluorides; (1)0.05% NaF fluoride solution (2)1.23% APF gel and (3)0.1%F fluoride varnish, microhardness(VHN) and Diagnodent scores were measured and the surfaces of each treated specimens were also observed with SEM under 1500 magnification. The results were as follows: 1. In the change of microhardness(VHN), it decreased to 34.68% from the initial micrhardness, increased to 78.37% after laser irradiation and increased to 82.62% after fluoride treatment, there were significant differences except when it was irradiated and treated with fluoride(P<0.05). 2. In the change of Diagnodent scores, it was decreased to 28.08% from the initial scores after demineralization, and then increased to 59.81% after laser irradiation, and increased to 82.17% after fluoride treatment. Scores were different significantly between the scores of initial, demineralization, laser irradiation and fluoride treatment(P<0.05). All the scores were not different significantly between fluoride types. 3. SEM observation showed that the lased enamel surfaces after demineralization were thermally degenerated and showed molten lava-like appearance and crater with cracks and many microholes.

• Journal of Technologic Dentistry
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• v.26 no.1
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• pp.9-34
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• 2004

The present study reviews the license registration status of dental technicians and dentists from 1970 to 2002, the number of technician members of The Korea Dental Technician Association from 1990 to 2003, and the number of dentist members in 2003. It also considers the yearly membership fluctuations, its growth rates, yearly increase/decrease, the rate of dentist to dental technician, regional distribution of association members, regional yearly increase/decrease of the members, and the regional distribution of dentists and dental technicians. The purpose is to identify and predict the problems in the demand/supply of dental technicians and the regional imbalance of manpower distribution. By doing so, this study attempts to propose the appropriate standard for the supply of dental technicians and point out the necessity of making mid- or long-term plans for ensuring the efficiency of manpower supply and balanced regional distribution. The result is as follows: 1. The number of dental technicians and dentists in 2002 has grown 36.79 and 9.27 times from 1970, and 2.20 and 2.05 times from 1990, respectively. It tool 11 years for the twofold increase of dental technicians from 1990, one year faster than the same increase of dentists. The number of dental technicians per a dentist was the lowest in 1972 (0.21 person), and the highest in 2002 (0.86 person). Specifically, the fastest growth was observed for a year from 1983 (0.47 technician per a dentist) to 1984 (0.6). From 1984 to 1986, the ratio grew by 0.1 every year. Summing up the numbers of dentists and dental technicians who passed the national certification examination, this study predicted the number of dental technicians per a dentist to be 0.88 in 2003, and 0.90 in 2004. 2. From 1990 to 2003, the average distribution of dental technician was 71.76% in the metropolitan areas and 28.24% in other smaller regions. The proportion of dental technicians working in the three major cities (Seoul, Busan, and Daegu) was the lowest in 2001 (52.39%) and the highest in 1996 (62.66%). The majority number of dental technicians who practiced in the metropolitan areas (about 70% of the entire population) were in service in the three major cities. 3. Compared with 1990, the number of dental technicians in 2003 grew 2.28 times in the large cities, and 2.05 times in other smaller regions. The yearly growth rate was the highest in 1994 over the previous year: 26.06% in large cities and 17.86% in the other regions. In the large metropolitan cities, the growth rate was the highest in Incheon (5.8 times for 5 years from 1998 to 2003), In the rest of the regions, the increase of dental technicians was the highest in Gyeonggi (6.5 times from 1990 to 2003). 4. In 2003, as much as 73.40% of all the members of the Korea Dental Technician Association were distributed in the large metropolitan cities, and the rest 26.60% were in other smaller regions. Meanwhile, 54.35% of the dentists practiced in the metropolitan cities, and the rest 45.65% were in service at other regions. This result indicates that more dental technicians than dentists are concentrated in large cities. More than half of all the technician members of the Association are distributed in the three major cities (i.e. Seoul, Busan, Daegu). On the other hand, 42.03% of dentist members are in these three cities and 53.97% of them practice in Seoul, Gyeonggi, and Busan. In 2003, the ratio of dentist to dental technician is 1:0.43 in general, while the ratio is 1:0.58 in the metropolitan cities, and 1:0.43 in other regions. In 2003, 33.30% of all the certified dental technicians are the member of the Korea Dental Technician Association, while 66.82% of all the licensed dentists are its members.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.12
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• pp.1553-1559
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• 2007

The purposes of this study were to investigate the effect of Saengshik on blood glucose level of normal subject and to explore the marketing possibility of four kinds of Saengshik (ES, HS, BS, SS) as alternative diabetic meals. Blood glucose levels of healthy volunteers was measured at 15, 30, 45, 60, 75, 90, 105 and 120 minutes after taking Saengshik and 50 g glucose. Blood glucose response areas, glycemic index (GI) and glycemic load (GL) were calculated from the glucose response. The Saengshik showed a significantly lower glucose level than the glucose. The glycemic index (GI) of ES showed $43.1{\pm}12.6$, which belonged to low GI foods (GI of 55 or less). Other samples (HS, BS, SS) could be classified as intermediate GI foods ranging $56{\sim}69$ of GI. Saengshik showed a gentle rising and falling pattern showing moderate left area ratio and right area ratio on blood glucose curve. The GL of ES showed 14.1 while HS, BS and SS did $19.2{\sim}19.5$. The results indicated that Saengshik may have a beneficial effect on a diabetic.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.1
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• pp.87-94
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• 2012

We evaluated the bioavailability of a novel organic Ca supplement chelated with milk protein (CaMP) in growing rats and compared it with those of Ca carbonate and Ca citrate. Four-week-old male rats were divided into six groups (n=6/group) and fed AIN-93G-based experimental diets containing three Ca sources, Ca carbonate, Ca citrate, and CaMP at two levels, normal (0.5%, w/w) and high (1.5%, w/w), for 6 weeks. Growth, mineral contents of serum, Ca content and breaking force of femur, and Ca absorption were measured. There were no significant differences in weight gain or food intake, but food efficiency ratio (FER) of CaMP in the high Ca group was higher than those of other groups. Ca and P concentrations in serum were within normal range in all experimental rats. There was no difference in Ca content of the femur among all of the groups. Although there was no statistical significance in bone breaking force of the femur among the groups, the CaMP groups had a higher breaking force compared to other groups. Further, Ca absorption rate significantly increased in the CaMP groups (p<0.05). These results demonstrate that the CaMP supplement did not exhibit any negative effect on growth or Ca metabolism of the rats. Therefore, CaMP can be recommended as a good Ca supplement with regard to bone metabolism and Ca bioavailability.

• Journal of Korean Society of Forest Science
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• v.99 no.1
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• pp.85-95
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• 2010

The purpose of this study was to quantitatively measure both growth performances and nutrient responses of Fraxinus rhynchophylla, Fraxinus mandshurica, Pinus koraiensis, and Abies holophylla seedlings, which are commercially planted in Korea, to nitrogen, phosphorus, and potassium fertilization. We used Dickson's quality index (QI) to compare growth performances and vector diagnosis to interpret nutrient status. Nitrogen fertilization increased more height and root collar diameter growth in F. rhynchophylla and F. mandshurica relative to no fertilization treatment. The QI of F. rhynchophylla and F. mandshurica was the highest on N treatment, but there were no significant differences between treatments for P. koraiensis and A. holophylla. Nitrogen fertilization increased total dry weight by 43, 41, 26, -9% for F. rhynchophylla, F. mandshurica, P. koraiensis and A. holophylla, respectively. In F. rhynchophylla, N fertilization increased N contents with similar N concentrations ("sufficiency"), decreased both P concentrations and P contents ("antagonism"), and decreased K contents with similar K concentrations ("toxic accumulation"). In P. koraiensis, N fertilization decreased N, P, and K concentrations because of more dry weight increases compared to uptaken contents ("dilution"), but N fertilization decreased N, P, and K contents with similar N, P, and K concentrations ("toxic accumulation"). In the light of quality index and vector diagnosis, F. rhynchophylla and F. mandshurica seedlings treated with N fertilization would have high field performance.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.9
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• pp.1153-1160
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• 2009

Monascus-fermented Korean red ginseng (MFRG), fermented by Monascus purpureus KCCM 12002, may be an ideal candidate for the hepatoprotectic, hypolipidemic and antioxidative activities. Effect of MFRG powder on these parameters in rats was investigated. Body weight gain, food intake, and water consumption were not significantly different among the groups. Total and relative weights of liver were significantly higher in MFRG group than that in other groups. The activities of AST and $\gamma$-GTP were highly lowered in MFRG group compared to control group. Contents of serum total lipid and triglyceride were significantly lowered in silymarin group and were significantly increased in MFRG group compared to control group, but tended to be lowered in RG group. Serum content of total cholesterol tended to be lowered in silymarin, RG, and MFRG groups compared to control group. HDL-cholesterol contents was only significantly increased in MFRG group compared to control group. At the same time, atherogenic index (AI) was also significantly lowered in silymarin, RG and MFRG groups compared to control group, and this effect was more pronounced in MFRG group. Content of thiobarbituric acid reactive substances (TBARS) in the liver was significantly lowered in MFRG group and tended to lowered in silymarin and RG groups compared to control group. The hepatic glutathione concentration was significantly higher in silymarin and MFRG groups. Hepatic morphology in all experimental groups revealed clear-cut hepatic lobules with the uniform pattern of the polyhedral hepatocytes radiating towards the periphery from the central vein. These results suggested that MFRG may have anti-atherogenic index (AI) and antioxidative activity in normal dietary feeding rats.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.10
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• pp.1664-1672
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• 2013

Solar salt is manufactured naturally, and therefore, it contains insoluble substances such as sandy compounds. This study is performed in order to effectively produce clean sea salt by removing the impurities in sea salt through filtration and evaporation in a vacuum condition. Brine was concentrated and crystallized at $90^{\circ}C$ by a rotary vacuum evaporator, which was then recovered as salt crystals by filtration, and then the salt was dehydrated. Manufacturing yields were determined by the amount of water evaporation. Brine was concentrated to 40%, 50% and 60% of the initial volume of brine and manufactured salt were designated as 40S, 50S and 60S, respectively. The salt produced by this process is called ESBS (evaporated salt with brine from salt-farm). The yield of 40S, 50S and 60S were 7.22%, 10.79% and 15.06%, respectively. The NaCl concentration of 40S and 50S were 90.38% and 91.16%, respectively. From a sensory evaluation analysis, the most tasty salt was 40S and the bitter salt was 60S. The average contents of sand compound and insoluble substances in ESBS were 0.001~0.012% and 0.067~0.12%, respectively. The mineral compositions, such as Na, Mg, K, and Ca of 40S and 50S were similar with those of the natural solar salt. In solubility tests, the solubility (g of salt/100 mL $H_2O$/sec) of 40S, 50S, and 60S was 0.69, 0.70, and 0.69, respectively. On the other hand, the solubility of natural solar salt was 0.47. By comparing the water reabsorption rate analysis results, water reabsorption rate of 40S and 50S was about 3 to 5 times lower than that of the solar salt. In the aspects of physical and chemical properties, such as minerals, impurities, solubility and moisture re-absorption rate, salts developed in this study are judged to be better than that of the general solar salt.

• Journal of Gastric Cancer
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• v.5 no.4 s.20
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• pp.295-303
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• 2005

The Korean laparoscopic Gastrointestinal Surgery Study Group made a survey of laparoscopic gastric surgeries which were performed in Korea during 2004. Thirty-eight surgeons from 36 Institutions responded to the questionnaires. One thousand eighty-nine laparoscopic gastric operations were performed during 2004. The cumulative number from 1995 to 2004 was about 2,386. Seven hundred fifty-four operations for a gastric adenocarcinoma were performed during 2004 which is almost two times the number performed during 2003. Laparoscopic radical procedures, such as a laparoscopy-assisted distal gastrectomy or total gastrectomy (LADG and LATG) have increased rapidly since 2001 (55 cases in 2001, 150 cases in 2002, 364 cases in 2003 and 738 cases in 2004). Especially, laparoscopic total gastrectomies were explosively adopted last year (20 cases in 2003 and 112 cases in 2004). However, laparoscopic function-preserving gastrectomies, which included one laparoscopy-assisted pylorus-preserving gastrectomy and laparoscopy-assisted proximal gastrectomy, are rarely performed at this time. One hundred forty-two wedge resections for a gastric submucosal tumor were performed during 2004. Hand-assisted laparoscopic surgery (HALS) was performed in 39 cases in 2001, 55 in 2002, and 49 in 2003; however, only 5 such surgeries were performed during 2004. In 2003, laparoscopic bariatric surgery began, and during 2004, 49 operations were performed. In terms of indications of laparoscopic gastric surgery for adenocarcinoma, 19 surgeons performed a LADG only for a T1 lesion, and 7 surgeons extended their indications to T2N0 lesions. In the near future, laparoscopic procedures for gastric cancer will be widely adopted in Korea if the medical-insurance obstacle is overcome, and the long-term survival results are verified.

• Journal of Gastric Cancer
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• v.5 no.4 s.20
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• pp.273-280
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• 2005

Purpose: Cyclin G2 has been reported to be a negative cell-cycle regulator in various cancer tissues. However, the pattern of cyclin G2 expression in gastric cancer is relatively unknown. We investigated the expression of cyclin G2 in gastric cancer tissues and evaluated the clinical significance of its expression. Materials and Methods: Well-preserved gastric cancer tissues were consecutively obtained from 172 patients who underwent gastric cancer operations at Samsung Medical Center between November 1994 and December 1997. Cyclin G2 expression in the tissues was examined immunohistochemically, and the clinicopathological features and prognostic significance according to the expression were analyzed. Results: Of the 172 gastric cancer tissues, cyclin G2 expression was positive in 43 tissues (25.0%). According to the stage, cyclin G2 expression was lower in more advanced stages (P<0.001). Negative expression of cyclin G2 was positively correlated with more advanced depth of tumor invasion (P<0.05), presence of lymph-node metastasis (P<0.05) and presence of lymphatic invasion (P<0.05). The prognosis of the cyclin G2(+) group was significantly better than that of the cyclin G2(-) group (P<0.001). Multivariate analysis revealed that T stage, lymph-node metastasis, distant metastasis, and lymphatic invasion were independent prognostic factors, but the expression of cyclin G2 was not. Conclusion: Cyclin G2 was expressed in 25% of the gastric cancer tissues, and negative expression of cyclin G2 was associated with more advanced tumor progression. Cyclin G2 may be a negative cell-cycle regulator in gastric cancer, and further studies are necessary to elucidate its exact role in the mechanism of carcinogenesis.

• Journal of Gastric Cancer
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• v.5 no.4 s.20
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• pp.238-245
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• 2005

Purpose: Ghrelin, produced primarily in the gastrointestinal tract, including the stomach, has been reported to reflect nutritional status and to control homeostasis by influencing food intake and adiposity. The purpose of this study is to evaluate nutritional status, as well as plasma and gastric tissue ghrelin levels, in patients with gastric cancer who underwent a gastrectomy. Materials and Methods: Eighty patients were analyzed by the degree of weight loss $(weight\;loss{\geq}5%\;or\;<5%)$ and the extent of gastrectomy (subtotal or total gastrectomy). Blood samples were collected from all patients preoperatively and postoperatively especially at seven days. Gastric tissues, including tumor and normal tissues, were obtained from the resected stomach. levels of plasma and tissue ghrelin were measured with a commercial ELISA kit. Results: There were no significant differences in the clinical characteristics and ghrelin levels of plasma, gastric tumor tissue and normal tissue by the degree of weight loss. The ghrelin levels in plasma and tumor tissue showed no correlations with each other while the ghrelin level in tumor tissue was significantly lower than that in normal tissue. The degree of cellular differentiation also had an association with ghrelin production. A gastrectomy proved to decrease significantly plasma ghrelin levels, body mass index, and biochemical markers, regardless of the extent of gastric resection. Conclusion: These results show that gastric cancer affects the production of ghrelin in the gastric mucosa and that ghrelin is mainly produced in stomach even though it could be partially covered by endogenous ghrelin from other organs following a gastrectomy. However, we should further investigate which other factors have an impact on energy consumption, ghrelin secretion, and changes in ghrelin levels after a gastrectomy.