• The Journal of Korean Academy of Prosthodontics
• /
• v.47 no.4
• /
• pp.445-456
• /
• 2009

Statement of problem: Many studies have been conducted to improve the primary stability of implants by providing bioactive surfaces via surface treatments. Increase of surface roughness may increase osteoblast activity and promote stronger bonding between bone and implant surface and it has been reported that bioactive surface or titanium can be obtained through alkali and heat treatment. Purpose: The purpose of this study was to evaluate the stability of alkali and heat treated implants via histomorphometric analysis. Material and methods: Specimens were divided into three groups; group 1 was the control group with machined surface, the other groups were treated for 24 hours in 5 M NaOH solution and heat treated for 1 hour at $600^{\circ}C$ in the atmosphere (group 2) and vacuum (group 3) conditions respectively. Surface characteristics were analyzed and fixtures were implanted into rabbits. The specimens were histologically and histomorphometrically compared according to healing periods and change in bone composition were analyzed with EPMA (Electron Probe Micro Analyzer). Results: 1. Groups treated with alkali and heat showed increase of oxidization layer and Na ions. Groups 2 which was heat treated in atmosphere showed significant increase of surface roughness (P<.05). 2. Histomorphometric analysis showed significant increase in BIC (bone to implant contact) according to increase in healing period and there was significant increases in groups 2 and 3 (P<.05). 3. BA(bone area) ratio showed similar results as contact ratio, but according to statistical analysis there was significant increase according to increase in healing period in group 2 only (P<.05). 4. EPMA analysis revealed no difference in gradation of bone composition of K, P, Ca, Ti in surrounding bone of implants according to healing periods but groups 2 and 3 showed increase of Ca and P in the initial stages. Conclusion: From the results above, it can be considered that alkali and heat treated implants in the atmosphere have advantages in osseointegration in early stages and may decrease the time interval between implantation and functional adaptation.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.1
• /
• pp.135-140
• /
• 2014

Pre-storage ultra-violet (UV) light treatment on fresh produce is known to inactivate the contaminated microorganisms, activate the defense system, and delay ripening extending the shelf life. As UV light emitting diode (LED) becomes available at a relatively low price, continuous or intermittent UV treatment during chilled storage is possible in a container or package. This study attempted an in situ UV LED treatment on fresh produce stored under a refrigerated container in order to see its potential in the fresh produce storage and further optimize its application conditions. The effect of in-container UV LED irradiation on the quality preservation of shredded carrots was investigated in the air and modified atmosphere (MA) conditions. Two sets of experiment with Escherichia coli inoculation and with natural microbial flora in the air (two 30 minute on-off cycles of 1 $diode/dm^2$ per day at a location above 2 cm) showed a clear and significant effect of the UV LED irradiation on the suppression of microbial growth: 280 nm was the most effective by maintaining a lower microbial count by at least 0.5 log (CFU/g) throughout the 6 day storage period. The carotenoids content of shredded carrots subjected to UV LED treatment at 365 and 405 nm in the air was higher than that of the control shredded carrots. In MA condition of $O_2$ of 1.2~4.3% and $CO_2$ of 8.4~10.6% being indifferent with LED wavelengths, 280 nm UV LED irradiation was also effective in inhibiting the microbial growth. While there was no observed difference in the carotenoids content between untreated and UV LED-treated shredded carrots in MA, UV LED irradiation at 365 and 405 nm was slightly better in DPPH radical scavenging activity. The use of UV LED in storage container or package seems to give the benefits of preserving the microbial and nutritional qualities of minimally processed fruits and vegetables.

• Journal of Radiation Protection and Research
• /
• v.40 no.1
• /
• pp.10-16
• /
• 2015

Bone changes are common sequela of irradiation in growing animal. The purpose of this study was to establish an experimental model of radiation-induced bone loss in growing mice using micro-computed tomography (${\mu}CT$). The extent of changes following 2 Gy gamma irradiation ($2Gy{\cdot}min^{-1}$) was studied at 4, 8 or 12 weeks after exposure. Mice that received 0.5, 1.0, 2.0 or 4.0 Gy of gamma-rays were examined 8 weeks after irradiation. Tibiae were analyzed using ${\mu}CT$. Serum alkaline phosphatase (ALP) and biomechanical properties were measured and the osteoclast surface was examined. A significant loss of trabecular bone in tibiae was evident 8 weeks after exposure. Measurements performed after irradiation showed a dose-related decrease in trabecular bone volume fraction (BV/TV) and bone mineral density (BMD), respectively. The best-fitting dose-response curves were linear-quadratic. Taking the controls into accounts, the lines of best fit were as follows: BV/TV (%) = $0.9584D^2-6.0168D+20.377$ ($r^2$ = 0.946, D = dose in Gy) and BMD ($mg{\cdot}cm^{-3}$) = $8.8115D^2-56.197D+194.41$ ($r^2$ = 0.999, D = dose in Gy). Body weight did not differ among the groups. No dose-dependent differences were apparent among the groups with regard to mechanical and anatomical properties of tibia, serum ALP and osteoclast activity. The findings provide the basis required for better understanding of the results that will be obtained in any further studies of radiation-induced bone responses.

• Tuberculosis and Respiratory Diseases
• /
• v.49 no.2
• /
• pp.217-224
• /
• 2000

Background : It is well known that when macrophages are stimulated with endotoxin, they produce a wide variety of cytokine mediators, including TNF-$\alpha$ and IL-1$\beta$. However, there is an alteration in the macrophages' responsiveness when they are challenged with repeated bouts of endotoxin, termed "endotoxin tolerance" which is regarded as a self-protective phenomenon from continuous stimulation. In this study, endotoxin tolerance in the peripheral blood monocytes of sepsis patients was evaluated. Methods : Fourteen patients with organism-documented sepsis were included. The severity of illness was evaluated by APACHE II score. Peripheral blood monocytes were isolated from the patients and diluted to $1{\times}10^5$ well. After stimulation with endotoxin (LPS of E. coli O114 : B4, 100 ng/ml), they were incubated at $37^{\circ}C$ in 5% $CO_2$ incubator for 24 hours. Supernatant was collected for the measurement of TNF-$\alpha$ and IL-1$\beta$ with ELISA method. Peripheral blood monocytes of seven healthy volunteers were used as control. Results : The APACHE II score (mean$\pm$SD) of the patients at the time of blood sampling was 12.2$\pm$5.7. The primary infection foci were urinary tract infection, pneumonia, subacute bacterial endocarditis, and catheter related infection, etc. The causative organisms were gram negative rods (10 cases), gram positive cocci (6 cases) with two cases of mixed infection. Serum TNF-$\alpha$ could be measured in 4 cases with 29.9$\pm$27.7 pg/ml. Serum IL-1$\beta$was measurable in only one patient. The TNF-$\alpha$ level of supernatant of cultured peripheral blood monocytes was 2,703$\pm$2,066 pg/ml in patients and 2,102$\pm$1914 pg/ml in controls. The IL-1$\beta$level of supernatant was 884$\pm$1,050 pg/ml in patients and 575$\pm$558 pg/ml in controls. There was no difference of TNF-$\alpha$ and IL-1$\beta$ level between patients and controls. Conclusion : We cannot prove the phenomenon of endotoxin tolerance in this study. Future study needs to be focused on the more severe sepsis patients who were taken for sampling earlier. Addition of serum to the culture medium could be an another valuable option for the success of this study.

• Tuberculosis and Respiratory Diseases
• /
• v.47 no.4
• /
• pp.460-470
• /
• 1999

Background : In 1993, American Thoracic Society (ATS) recommended a guideline for the initial management of adults with community-acquired pneumonia(CAP). However, etiologic organisms and medical system in Korea seem to be different from those in Western countries. Retrospective analysis was done to evaluate the efficacy of antibiotics chosen by ATS guideline in the treatment of Korean patients with CAP admitted to a tertiary university medical center. Methods : Hospitalized patients with CAP at Samsung Medical Center from April 1997 through March 1998 were retrospectively reviewed. Patients who fulfilled all of the following criteria were included in this study : (1) fever ${\geq}38^{\circ}C$ (2) purulent sputum (3) pulmonary infiltrates on chest X-ray. Patients were classified as : 1) ATS group ; patients whose initial antibiotics were chosen by ATS guideline 2) Non-ATS overuse group ; additional antibiotics administered more than those of ATS guideline, and 3) Non-ATS underuse group ; initial antibiotics were insufficient to ATS guideline. Response of empirical antibiotics and etiologic organisms of 3 groups were identified. Results : Sixty-four patients were enrolled. Thirty-six patients were classified into ATS group, 10 patients Non-ATS overuse group, and 18 patients Non-ATS underuse group. Thirty-three patients of 36 ATS group, 9 patients of 10 Non-ATS overuse group, and 14 patients of 18 Non-ATS underuse group showed improvement by initial empirical antibiotics. There was no statistical difference in antibiotic response between 3 groups (p>0.05). S. pneumoniae (12.5%), K. pneumoniae (9.4%), and P. aeruginosa (4.7%), Mycoplasma (3.1%) were the most commonly isolated organisms. In 18 patients with severe CAP, P. aeruginosa was isolated only in 1 patient and Legionella organism not isolated. Conclusion : Initial empirical antibiotics chosen by ATS guideline were effective in the management of Korean patients with CAP admitted to a tertiary hospital. However, well-designed large-scale prospective study is needed to identify etiologic organisms and choose an adequate initial empirical antibiotics in Korean adults patient with severe CAP.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.10
• /
• pp.1356-1362
• /
• 2006

The purpose of the present study was to investigate the effect of enzymatic hydrolysate (extract) of Salicomia herbacea L. (Korean name: Hamcho) on antioxidative defense system in rats fed high cholesterol diet. Rats were divided into six experimental groups which are composed of normal diet group, normal diet group supplemented with 2% Hamcho extract, high cholesterol diet group, high cholesterol diet groups supplemented with 1%, 2% and 4% Hamcho extracts. The activity of serum glutamate oxaloacetae transaminase in rats was not different among all experimental groups, while the activity of glutamate pyruvate transaminase in groups supplemented with Hamcho extract was significantly lower than that of high cholesterol control group. Supplementation of Hamcho extract (SHE) to the high cholesterol fed rats resulted in increased activities of hepatic superoxide dismutase and glutathione peioxidase. However, there was no significant difference in the activity of hepatic catalase among all experimental groups. SHE also resulted in decreased levels of hepatic thiobarbituric acid reactive substances and mitochondrial carbonyl values. Those effects were higher to some extent in 2% and 4% Hamcho extract groups than those of high cholesterol control group. These results suggest that enzymatic hydrolysate of Hamcho may reduce oxidative damage by activation of antioxidative defense system in rats fed high cholesterol diets.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.37 no.2
• /
• pp.217-222
• /
• 2008

The aim of the present study was to evaluate the effect of marination with mixed salt (NaCl, $CaCl_2$, and phosphate) and kiwi juice and of different cooking methods for pork loin-based products in order to establish the basic database for increasing the consumption of pork loin in Korea. Diced chilled pork loin ($2{\times}2{\times}2\;cm$) was marinated in 4 different treatments: no additives (T1), salt mix only (T2), kiwi juice only (T3), and salt mix+kiwi juice (T4). The mixed salt was prepared by the addition of NaCl, $CaCl_2$, and phosphate dissolved in water (10% of pork loin weight) at concentrations of 0.5, 0.5, and 0.3% per pork loin weight, respectively. The amount of kiwi juice was 10% of pork loin weight. After marination for 24 hrs at $4^{\circ}C$, the samples were cooked with different methods including roasting with Kimchi, pan broiling, and simmering. After simmering, pH of pork loin of T1 and T2 was higher than that of T3 and T4 (p<0.05), while that of roasted with Kimchi and pan broiled did not show any difference. Water holding capacity of T4 after pan broiling was higher than that of T1, T2, and T3 (p<0.001) and shear force of T4 was lower than other treatments. Also flavor and acceptability of T4 after pan broiling were scored higher by 11 sensory panelists (p<0.05). From this result, the pork loin-based products marinated with mixed salt and kiwi juice with pan broiling would be preferred by consumers as one of the methods to promote the consumption of pork loin in Korea.

• Korean journal of applied entomology
• /
• v.46 no.2
• /
• pp.193-199
• /
• 2007

This study was conducted to explain degree of injury caused by P. panopealis larva which is the key component to develop economic injury level or control threshold in green perilla and was carried out in polyvinyl houses at Yuseong Daejeon, Geumsan and Yesan Chungnam from 2004 to 2006. Of 5 major pests in green perilla polyvinyl house, P. panopealis larva injured green perilla leaf by 48.5% on average under no insecticides application. The peak occurrence of P. panopealis adult was early August and late September in 2004 and 2005 studies. The feeding amount of P. panopealis larva among 1st to 3rd instar was not different, but from the 4th instar the feeding amount greatly increased and this result was consistent with daily feeding experiment in which the amount greatly increased from seventh day. The degree of injury which was investigated with different larval infestation levels showed that the degree of injury increased a little but was not dim ε rent significantly as the density increased. The density of P. panopealis larva in damaged green perilla plant was less than three individuals/plant. This result indicates that P. panopealis adult lays egg on green perilla leaf dispersedly and larva hatched from egg injures only the leaf which egg is layed. These preliminary data seems to be very useful to design economic injury level and control threshold studies for P. panopealis in green perilla polyvinyl house.

• Progress in Medical Physics
• /
• v.9 no.2
• /
• pp.65-71
• /
• 1998

The aims are to evaluate the effects of an 1.0 cm acrylic plate and SSD on the dose profile and depth dose distribution of 9 MeV electron beam and to analyse adequacy for using an acrylic plate to reduce energy of electron beams. An acrylic plate of 1.0 cm thickness was used to reduce energy of 9 MeV electron beam to 7 MeV. The plate was put on an electron applicator at 65.4 cm distance from x-ray target. The size of the applicator was 10${\times}$l0cm at 100 cm SSD. For 100cm, l05cm and 110cm SSD, depth dose on beam axis and dose profiles at d$\_$max/ on two principal axes were measured using a 3D water phantom. From depth dose distributions, d$\_$max/, d$\_$85/, d$\_$50/ and R$\_$p/, surface dose, and mean energy and peak energy at surface were compared. From dose profiles flatness, penumbra width and actual field size were compared. For comparison, 9 MeV electron beams were measured. Surface dose of 7 MeV electron beams was changed from 85.5% to 82.2% increasing SSD from 100 cm to 110 cm, and except for dose buildup region, depth dose distributions were independent of SSD. Flatness of 7 MeV ranged from 4.7% to 10.4% increasing SSD, comparing 1.4% to 3.5% for 9 MeV. Penumbra width of 7 MeV ranged from 1.52 cm to 3.03 cm, comparing 1.14 cm to 1.63 cm for 9 MeV. Actual field size increased from 10.75 cm to 12.85 cm with SSD, comparing 10.32 cm to 11.46 cm for 9 MeV. Virtual SSD's of 7 and 9 MeV were respectively 49.8 cm and 88.5cm. In using energy reducer in electron therapy, depth dose distribution were independent of SSD except for buildup region as well as open field. In case of using energy reducer, increasing SSD made flatness to deteriorate more severely, penumbra width more wide, field size to increase more rapidly and virtual SSD more short comparing with original electron beam. In conclusion, it is desirable to use no energy reducer for electron beam, especially for long SSD.

• Proceedings of the KOR-BRONCHOESO Conference
• /
• 1978.06a
• /
• pp.4.1-4
• /
• 1978

The foreign bodies in the food and air passages are frequently observed in the field of otolaryngology, and the foreign bodies in the air passages have much significance in clinical practice because they may cause sudden death. A statistical study was done on 95 cases of foreign bodies in the food and air passages who had visited department of otolaryngology, Chung-Ang university from June, 1968 to April, 1978. The results were as follows; 1. The total cases of foreign bodies in the food and air passages was 95; 89 cases (93.7%) were in the food passage and the remaining (6.3%) were in the air passage. The ratio between the food passage and air passage was about 14. 8 to 1.0. 2. In distribution by sex, 64 cases (67.4%) were in male patients and the remaining 31 cases (32.6%) were in female patients. The ratio between male and female was 2.1 to 1.0. 3. The kinds of foreign bodies in the food in the order of their frequency, were coin, gogame stone and pebble. In the air passages, the peanut and bean were most frequently found. 4. In distribution by age, 64 cases (67.4%) of all foreign bodies were found in children under 5 year old, and coin was the most common kind of foreign body. Except for meat, almost all of foreign bodies were found in children under 10 year old. 5. There was chronologically no significant tendency in incidence; the incidence, however, had decreased during recent 2 years. 6. In the location of foreign bodies in the food passage, 70 cases (78.7%) were found at the first esophageal narrowing. Meat was more frequently found at second esophageal narrowing associated with cicatrical stenosis. Almost all of foreign bodies in the air passage was found in bronchi; 3 cases were in the right side of bronchi, and 2 cases were in the left side of bronchi and 1 case was in glottic region. 7. In duration of lodgement, 50 cases (52.6%) visited our hospital within 24 hours, and 3 cases after 30 days. 8. Under topical anesthesia, 83 cases (93.3%) of the foreign bodies in the food passage were removed by esophagoscopy, by 6 cases (6.7%) failed to be removed. All of the foreign bodies of the air passages (6 cases) were removed by bronchoscopy. Among them, 5 cases under 5 years old were removed by inferior bronchoscopy through tracheostomy site.