• Korean Journal of Materials Research
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• v.21 no.7
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• pp.384-390
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• 2011

Ti-6Al-4V ELI (Extra Low Interstitial) alloy has been widely used as an alternative to bone due to its excellent biocompatibility. However, it still has many problems, including a high elastic modulus and toxicity. Therefore, nontoxic biomaterials with a low elastic modulus should be developed. However, the fabrication of a uniform coating is challenging. Moreover, the coating layer on Ti and Ti alloy substrates can be peeled off after implantation. To overcome these problems, it is necessary to produce bulk Ti and Ti alloy with hydroxyapatite (HA) composites. In this study, Ti, Nb, and Zr powders, which are biocompatible elements, were milled in a mixing machine (24h) and by planetary mechanical ball milling (1h, 4h, and 6h), respectively. Ti-35%Nb-7%Zr and Ti-35%Nb-7%Zr-10%HA composites were fabricated by spark plasma sintering (SPS) at $1000^{\circ}C$ under 70MPa using mixed and milled powders. The effects of HA addition and milling time on the biocompatibility and physical and mechanical properties of the Ti-35%Nb-7%Zr-(10%HA) alloys have been investigated. $Ti_2O$, CaO, $CaTiO_3$, and $Ti_xP_y$ phases were formed by chemical reaction during sintering. Vickers hardness of the sintered composites increases with increased milling time and by the addition of HA. The biocompatibilty of the HA added Ti-Nb-Zr alloys was improved, but the sintering ability was decreased.

• Korean Journal of Head & Neck Oncology
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• v.21 no.1
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• pp.26-31
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• 2005

Backgrounds and Objectives: Squamous cell carcinomas of the oral cavity(SCOC) in TNM stage I & II have relatively high chance to be cured compared to those in the advanced stage, but sometimes result in the treatment failure with poor prognosis. There have been few reports on the patterns of failure and the clinical courses for SCOC in stage I & II after the failure of initial treatment. This study is directed at identifying the clinical outcomes of stage I & II SCOC and the salvage rate after initial treatment and suggesting an optimal level of treatment by analyzing the patterns of failure. Material and Methods: The medical records of 36 patients with SCOC, initially diagnosed between 1995 and 2001 as TNM stage I & II were reviewed retrospectively. The patterns of failure, salvage treatment, clinical courses, and the survival of these subjects were analyzed. The minimum follow-up period of no-evidence of disease(NED) was 12 months with an average of 32.2 months. Results: Overall rate of the treatment failure in SCOC of stage I & II was 41. 7%(15/36 cases). Most of the treatment failure in the subjects with stage I tumors occurred in regional lymph node. Local failure was the most frequent form of failure in the subjects with stage II tumors after wide excision of primary tumor with elective neck dissection and/or radiation therapy. No significant correlation was noted between the safety margin and the local failure. Elective neck dissections in stage I & II SCOC had a tendency to reduce regional failure (p=0.055). The salvage rates at 24 months were 85.7% in stage I, and 37.5% in stage II. The 3-year survival rate after the failure of initial treatment was 55.0%. Conclusion: SCOC of stage I & II after the failure of initial treatment showed poor prognosis despite of the salvage treatments. This study implies that the elective neck dissections for regional lymph node should be required for SCOC of stage I & II to reduce the treatment failure.

• Journal of Korean Neurosurgical Society
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• v.29 no.4
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• pp.461-470
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• 2000

Objective : Many investigators have demonstrated the protective effects of hypothermia following traumatic brain injury(TBI) in both animals and humans. It has long been recognized that mild to moderate hypothermia improves neurologic outcomes as well as reduces histologic and biochemical sequelae after TBI. In this study, two immunohistochemical staining using terminal deoxynucleotidyl-transferase-mediated biotin dUTP nick end labeling(TUNEL), staining of apoptosis, and ${\beta}$-amyloid precursor protein(${\beta}$-APP), a marker of axonal injury, were done and the authors evaluated the protective effects of hypothermia on axonal and neuronal injury after TBI in rats. Material and Method : The animals were prepared for the delivery of impact-acceleration brain injury as described by Marmarou and colleagues. TBI is achieved by allowing of a weight drop of 450gm, 1 m height to fall onto a metallic disc fixed on the intact skull of the rats. Fourty Sprague-Dawley rats weighing 400 to 450g were subjected to experimental TBI induced by an impact-acceleration device. Twenty rats were subjected to hypothermia after injury, with their rectal temperatures maintained at $32^{\circ}C$ for 1 hour. After this 1-hour period of hypothermia, rewarming to normothermic levels was accomplished over 30-minute period. Following 12 hours, 24 hours, 1 week and 2 weeks later the animals were killed and semiserial sagittal sections of the brain were reacted for visualization of the apoptosis and ${\beta}$-APP. Results : The density of ${\beta}$-APP marked damaged axons within the corticospinal tract at the pontomedullary junction and apoptotic cells at the contused cerebral cortex were calculated for each animal. In comparison with the untreated controls, a significant reduction in ${\beta}$-APP marked damaged axonal density and apoptotic cells were found in all hypothermic animals(p<0.05). Conclusion : This study shows that the posttraumatic hypothermia result in substantial protection in TBI, at least in terms of the injured axons and neurons.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.3
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• pp.313-320
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• 2016

In the present study, we examined whether or not an herbal mixture extract (HME) has attenuation effects on immobilization stress and sleep disturbance in rats. Immobilization stress was induced by restricting movement using a constraint box for 2 h, and sleep disturbance was induced by exposure to 300 lx of constant light for 24 h and injection of caffeine (1 mg/kg, i.p.). Rats were orally treated with distilled water (vehicle) or HME for 3 weeks at different doses of 10, 30, and 100 mg/kg/d (HME I, II, and III, respectively). In the immobilization model, HME III treatment significantly decreased adrenal gland weight, whereas HME II and III treatment reduced plasma levels of cortisol. HME II and III also reduced the level of IL-6. In the sleep disturbance model, HME II and III meaningfully reduced the plasma level of cortisol, and the increased plasma level of melatonin. HME III significantly increased body weight. HME reduced immobilization stress and ameliorated disturbance in rats. These findings suggest that HME may have beneficial potential for attenuation of sleep disturbance and stress.

• Journal of Trauma and Injury
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• v.28 no.2
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• pp.60-66
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• 2015

Purpose: Cultivator accidents are frequent and often lead to abdomino-perineal organ injury and, if severe, to death. This study presents the clinical characteristics, outcomes, and factors associated with mortality in patients who sustained an abdomino-perineal organ injury in cultivator accidents. Methods: We retrospectively analyzed the records of 53 patients who visited the emergency department of a tertiary hospital with abdomino-perineal organ injuries caused in cultivator accidents from April 2005 to March 2010. Results: All 53 patients had visited other medical institutions before visiting our hospital. Their mean age was $64.0{\pm}11.1$ (range, 20-80) years and 32 (60.4%) patients were 65 or older. The male-to-female ratio was 46:7. The chief complaint was abdominal pain (38 cases, 71.7%). The 53 patients included 41 cultivator operators (77.4%), 11 passengers (20.8%), and 1 passerby (1.9%). The causes of the injuries included a direct impact of the handlebar in 20 cases (37.7%), a rollover in 21 cases (39.6%), a fall in 10 cases (18.9%), and a wheel in two cases (3.8%). Several of the 53 patients had injuries to multiple abdomino-perineal organs, and the injured organs included the liver (23 cases, 26.4%), spleen (16 cases, 18.4%), pancreas (7 cases, 8.0%), small bowel (7 cases, 8.0%), mesentery (6 cases, 6.9%), adrenal gland (5 cases, 5.8%), and other organs. According to the abbreviated injury scale (AIS) dictionary, a thoracic injury was the most frequent co-injury (33 of 53 cases, 62.3%). Abdomino-perineal surgery was performed in 31 cases (58.8%) and angio-embolization was performed for six liver and two kidney injuries. Thirteen patients died (24.5%); all were males. The Injury Severity Scale (ISS) was lower in the survivors ($17.8{\pm}8.5$ vs. $27.0{\pm}16.0$; p=0.010). Conclusion: With the aging of agricultural workers, safety education programs should be implemented. Furthermore, the patient transfer system in agricultural areas must be improved.

• The Korean Journal of Malacology
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• v.29 no.3
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• pp.233-238
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• 2013

The effect of three different diets (formulated diet, FD; Undaria pinnatifida, UP; Laminaria japonica, LJ) on growth in the Haliotis discus hannai for 90 days was investigated. The shell length of UP ($80.62{\pm}1.92$ mm) and LJ ($81.14{\pm}1.16$ mm) were significantly faster than those of FD ($79.38{\pm}1.69$ mm) (P < 0.05). However, shell breadth and total weight were no significant difference among three diets. On the other hand, the weight gain of FD (16.65% for 0-45day and 25.71% for 45-90day) tend to have higher than those of UP (14.57% and 23.30%) and LJ (12.65% and 24.51%). This results shows that seaweed diets (UP and LJ) help the shell growth of abalone and formulated diet (FD) help the weight gain of abalone. Therefore, the growth of shell and muscle will depend on different diets.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1063-1070
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• 2011

In this study, total of 5 different chemical amendments were evaluated for determining kinetic parameters and stabilization efficiency of heavy metals in aqueous phase. Standard solution of Cd and Pb ($100mg\;L^{-1}$) was mixed with various ratio of amendments (1, 3, 5, 10%) and heavy metal stabilization efficiency was monitored for 24hrs. All examined amendments showed over 90% of removal efficiency for both Cd and Pb except zerovalent iron (ZVI) for Cd (43-63%). Based on result of heavy metal stabilization efficiency, it was ordered as $CaCO_3$ > Dolomite > Zeolite > Steel slag > ZVI for both Cd and Pb in aqueous phase. For kinetic study, first order kinetic model was adapted to calculate kinetic parameters. In terms of reaction rate constants (k), zeolite showed the fastest reaction rate (k value from 0.4882 for 1% to 2.0105 for 10%) for Cd and ZVI (k value from 0.2304 for 1% to 0.5575 for 10%) for Pb. Considering reaction rate constant and half life for heavy metal stabilization, it was ordered as Zeolite > $CaCO_3$ > Dolomite > Steel slag > ZVI for Cd and $CaCO_3$ > Dolomite > Steel slag > Zeolite > ZVI for Pb. Overall result in this study can be interpreted that lime containing materials are more beneficial to remove heavy metals with high efficiency and less time consuming than absorbent materials.

• Clinical and Molecular Hepatology
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• v.24 no.4
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• pp.374-383
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• 2018

Background/Aims: There have been numerous efforts to reduce mother-to-child transmission (MTCT) of hepatitis B virus (HBV) with antiviral agents during pregnancy. However, there are limited data regarding the outcomes of pregnant women after delivery. This study was performed to evaluate the efficacy of antiviral agents in preventing MTCT of HBV and maternal long-term outcomes. Methods: The HBV-infected pregnant women treated with antiviral agents to prevent MTCT were retrospectively reviewed. Forty-one pregnant women who received telbivudine or tenofovir during late pregnancy (28-34 week) were analyzed. Hepatitis B virus surface antibody (HBsAb) positivity was tested in 43 infants after 7 months of birth. Eleven mothers were followed >1 year after delivery. Results: The mean HBV DNA titer before antiviral therapy was 8.67 (6.60-9.49) log copies/mL, and the median age at delivery was 32 years (range, 22-40). Eleven patients were treated with tenofovir and 30 with telbivudine. The median duration was 57 days (range, 23-100), and the median HBV DNA titer at birth was 5.06 log copies/mL (range, 2.06-6.50). Antiviral treatments were associated with significant HBV DNA reduction (P<0.001). Among 43 infants (two cases of twins), HBsAb was not detected in two, subsequently confirmed to have HBV infection. Biochemical flare was observed in two of 11 mothers followed >12 months, and an antiviral agent was administered. Conclusions: Antiviral treatment during late pregnancy effectively reduced MTCT. Long-term follow-up should be required in such cases. In addition, given that maternal biochemical flare occurred in 18% of mothers, re-administration of antiviral agents might be required.

• Animal Bioscience
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• v.34 no.1
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• pp.74-84
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• 2021

Objective: Feed additives that modify rumen fermentation can be used to prevent metabolic disturbances such as acidosis and optimize beef cattle production. The study evaluated the effects of liquid and powdered forms of polyclonal antibody preparation (PAP) against Streptococcus bovis and Fusobacterium necrophorum on rumen fermentation parameters in ruminally cannulated non-lactating dairy cows that were adapted or unadapted to a high concentrate diet. Methods: A double 3×3 Latin square design was used with three PAP treatments (control, powdered, and liquid PAP) and two adaptation protocols (adapted, unadapted; applied to the square). Adapted animals were transitioned for 2 weeks from an all-forage to an 80% concentrate diet, while unadapted animals were switched abruptly. Results: Interactions between sampling time and adaptation were observed; 12 h after feeding, the adapted group had lower ruminal pH and greater total short chain fatty acid concentrations than the unadapted group, while the opposite was observed after 24 h. Acetate:propionate ratio, molar proportion of butyrate and ammonia nitrogen concentration were generally greater in adapted than unadapted cattle up to 36 h after feeding. Adaptation promoted 3.5 times the number of Entodinium protozoa but copy numbers of Streptococcus bovis and Fibrobacter succinogens genes in rumen fluid were not affected. However, neither liquid nor powdered forms of PAP altered rumen acidosis variables in adapted or unadapted animals. Conclusion: Adaptation of cattle to highly fermentable carbohydrate diets promoted a more stable ruminal environment, but PAP was not effective in this study in which no animal experienced acute or sub-acute rumen acidosis.

• Journal of Animal Science and Technology
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• v.63 no.2
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• pp.319-331
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• 2021

Heat stress (HS) causes adverse impacts on pig production and health. A potential biomarker of HS is required to predict its occurrence and thereby better manage pigs under HS. Information about the saliva metabolome in heat-stressed pigs is limited. Therefore, this study was aimed to investigate the effects of acute HS on the saliva metabolome and identify metabolites that could be used as potential biomarkers. Growing pigs (n = 6, 3 boars, and 3 gilts) were raised in a thermal neutral (TN; 25℃) environment for a 5-d adaptation period (CON). After adaptation, the pigs were first exposed to HS (30℃; HS30) and then exposed to higher HS (33℃; HS33) for 24 h. Saliva was collected after adaptation, first HS, and second HS, respectively, for metabolomic analysis using 1H-nuclear magnetic resonance spectroscopy. Four metabolites had significantly variable importance in the projection (VIP > 1; p < 0.05) different levels in TN compared to HS groups from all genders (boars and gilts). However, sex-specific characteristics affected metabolites (glutamate and leucine) by showing the opposite results, indicating that HS was less severe in females than in males. A decrease in creatine levels in males and an increase in creatine phosphate levels in females would have contributed to a protective effect from protein degradation by muscle damage. The results showed that HS led to an alteration in metabolites related to energy and protein. Protection from muscle damage may be attributed to the alteration in protein-related metabolites. However, energy-related metabolites showed opposing results according to sex-specific characteristics, such as sex hormone levels and subcutaneous fat layer. This study had shown that saliva samples could be used as a noninvasive method to evaluate heat-stressed pigs. And the results in this study could be contributed to the development of a diagnostic tool as a noninvasive biomarker for managing heat-stressed pigs.