• Bulletin of the Korean Chemical Society
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• v.16 no.11
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• pp.1109-1112
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• 1995

Bis(silyl)alkylbenzenes such as bis(1-sila-sec-butyl)benzene (1) and 2-phenyl-1,3-disilapropane (2) were prepared in high yields by reduction of the corresponding chlorosilanes with LiAlH4. The dehydropolymerization of 1 and 2 was carried out with group 4 metallocene complexes generated in situ from Cp2MCl2/Red-Al and Cp2MCl2/n-BuLi (M=Ti, Hf), producing two phases of polymers. The TGA residue yields of the insoluble polymers were in the range of 64-74%. The molecular weights of the soluble polymers produced ranged from 700 to 5000 (Mw vs polystyrene) and from 500 to 900 (Mn vs polystyrene). The dehydropolymerization of 1 and 2 seemed to initially produce a low-molecular-weight polymer, which then underwent an extensive cross-linking reaction of backbone Si-H bonds, leading to an insoluble polymer.

• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.611-618
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• 2006

Background: There have been controversies whether mitral valvular surgery is necessary in the patients with moderate ischemic mitral regurgitation undergoing coronary artery bypass grafting. The purpose of this study is to evaluate the long term clinical results of patients with moderate ischemic mitral regurgitation. Material and Method: Between January 1992 and February 2005, 44 patients with moderate ischemic mitral regurgitation underwent coronary artery bypass grafting. Concomitant mitral valvular procedure was performed in 20 patients (group 1) and isolated coronary artery bypass grafting was performed in 24 patients (group 2). There were no significant difference between groups except cardiopulmonary bypass time (p<0.01). Postoperative follow up duration was $30.1{\pm}29.6$ months and last follow up echocardiographic examination was performed at $21.2{\pm}28.0$ months. Result: There was no difference in operative mortality between groups (group 1 vs group 2, 15.0% vs 8.3%, p=0.493). Grade of mitral regurgitation ${(0.81{\pm}0.91\;vs\;1.50{\pm}0.05,\;p=0.046)}$ and reduction in regurgitation grade ${(1.75{\pm}0.93\;vs\;0.70{\pm}1.26,\;p=0.009)}$ were different between two groups. But there were no significant differences in left ventricular ejection fraction ${(34.1{\pm}11.4%\;vs\;41.6{\pm}12.9%)}$, left ventricular end systolic volume ${(118.2{\pm}63.9\;ml%\;vs\;85.6{\pm}281\;ml)}$, New York Heart Association functional class ${(2.1{\pm}0.2\;vs\;2.4{\pm}1.2)}$ and 5 year survival rate ${(85{\pm}8%\;vs\;82{\pm}8%)}$. There was no risk factor for operative mortality and the only risk factor for late death was preoperative atrial fibrillation (p=0.042). There was no significant correlation between mitral valvular surgery and late death. Conclusion: Concomitant mitral valvular procedure in patients with moderate ischemic mitral regurgitation undergoing coronary artery bypass grafting had no significant positive effect on survival and ventricular function compared with isolated coronary artery bypass grafting. Prospective randomized study may be needed to evaluate the necessity of concomitant mitral procedure and to find more effective method for the improvement of ventricular function.

• Korean Journal of Radiology
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• v.24 no.7
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• pp.681-689
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• 2023

Objective: Three-dimensional rotational angiography (3D-RA) is increasingly used for the evaluation of intracranial aneurysms (IAs); however, radiation exposure to the lens is a concern. We investigated the effect of head off-centering by adjusting table height on the lens dose during 3D-RA and its feasibility in patient examination. Materials and Methods: The effect of head off-centering during 3D-RA on the lens radiation dose at various table heights was investigated using a RANDO head phantom (Alderson Research Labs). We prospectively enrolled 20 patients (58.0 ± 9.4 years) with IAs who were scheduled to undergo bilateral 3D-RA. In all patients' 3D-RA, the lens dose-reduction protocol involving elevation of the examination table was applied to one internal carotid artery, and the conventional protocol was applied to the other. The lens dose was measured using photoluminescent glass dosimeters (GD-352M, AGC Techno Glass Co., LTD), and radiation dose metrics were compared between the two protocols. Image quality was quantitatively analyzed using source images for image noise, signal-to-noise ratio, and contrast-to-noise ratio. Additionally, three reviewers qualitatively assessed the image quality using a five-point Likert scale. Results: The phantom study showed that the lens dose was reduced by an average of 38% per 1 cm increase in table height. In the patient study, the dose-reduction protocol (elevating the table height by an average of 2.3 cm) led to an 83% reduction in the median dose from 4.65 mGy to 0.79 mGy (P < 0.001). There were no significant differences between dose-reduction and conventional protocols in the kerma area product (7.34 vs. 7.40 Gy·cm², P = 0.892), air kerma (75.7 vs. 75.1 mGy, P = 0.872), and image quality. Conclusion: The lens radiation dose was significantly affected by table height adjustment during 3D-RA. Intentional head off-centering by elevation of the table is a simple and effective way to reduce the lens dose in clinical practice.

• Archives of Craniofacial Surgery
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• v.14 no.2
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• pp.81-88
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• 2013

Background: To suggest the need of more aggressive reduction techniques than closed reduction (CR) technique in nasal fracture treatment, we identified the usefulness of algorithm oriented treatment of nasal fracture that includes indirect open reduction (IOR) and external fixation (EF) as well as the CR. Methods: We compared the clinical course of the group A (n=128) where only the CR was performed regardless of the pattern of the nasal fracture and the group B (n=127) where algorithm oriented treatment including IOR and EF as well as CR was performed depending on the pattern of nasal fracture. And the degree of postoperative pain after CR and IOR technique was compared through the dose of analgesics and pain scores. Results: More than 80% of patients were satisfied the result of reduction in both group A and B. Good contour of nasal bone after reduction was showed 71% of group A and 81% of group B without significant difference. Minor (p>0.05) and major (p<0.05) deformity after reduction were less occurred in the group B than group A. Postoperatively, the dose of analgesics was significantly lower after IOR technique than CR technique (53 mg vs. 142 mg) (p<0.05). Conclusion: Algorithm oriented treatment of nasal fracture including IOR and EF as well as CR reduce major deformity after reduction than treatment of CR alone. It is useful to perform the more aggressive reduction techniques such as IOR and EF according to the pattern of fracture in treatment of nasal fracture.

• Journal of the Korean Electrochemical Society
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• v.11 no.3
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• pp.170-175
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• 2008

Screen printed carbon electrodes (SPEs) modified with co-immobilized osmium-based redox polymers can be used to apply multi-detecting biosensors. In this study, we report our initial studies of multi-detecting biosensor concepts using two osmium-based redox polymers for horseradish peroxidase-mediated reduction of ${H_2}{O_2}$ coupled to glucose oxidase-mediated oxidation of glucose. We target to synthesize two osmium redox polymers of potentials use, a chloride-containing redox polymer ($E^{O'}$ + 0.520 vs. Ag/AgCl) and a methoxy-containing redox polymer $E^{O'}$ + 0.150 vs. Ag/AgCl). The former show good catalytic electrical signals with horseradish peroxidase and the latter's redox polymer is to be an effective redox mediator of glucose oxidation by glucose oxidase.

• Journal of Korean Neurosurgical Society
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• v.54 no.3
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• pp.220-224
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• 2013

Objective : This study aimed to determine the optimal time for tracheostomy by evaluating the benefits and safety of early versus late tracheostomy in spinal cord injury (SCI) patients. Methods : We retrospectively reviewed a total of 254 patients with spinal cord injury. Of them, we selected 21 spinal cord injury patients who required tracheostomy due to long-term mechanical ventilation and analyzed their medical records. The patients were categorized into two groups. Early tracheostomy was performed day 1-10 from intubation in 10 patients and the late tracheostomy was performed after day 10 in 11 cases. We also evaluated the duration of mechanical ventilation, stay in the ICU and complications related to tracheostomy, the injury level of and clinical severity. All data was analyzed using SPSS 18.0/WIN. Results : The early tracheostomy offered clear advantages for shortening the total ICU stay (20.8 day vs. 38.0 day, p=0.010). There was also statistically significant reduction in the total length of time on mechanical ventilation (5.2 day vs. 29.2 day, p=0.009). However, the reductions in the incidence of pneumonia (40% vs. 82%) and the length of ICU stay post to tracheostomy (6 day vs. 15 day) were found to be statistically not significant. There were also no statistically significant differences in the injury level and clinical severity between the groups. Conclusion : We concluded that the early tracheostomy (at least 10 days) is beneficial for SCI patients who are likely to require prolonged mechanical ventilation.

• Biomolecules & Therapeutics
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• v.6 no.4
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• pp.389-394
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• 1998

Cyclosporine (CsA) is a major immunosuppressive drug used widely to prevent organ allograft rejection. fits potential organotoxicity by prolonged use is known to cause both direct tissue damage and indirect pharmacokinetic interactions with other drugs. This study was performed to determine the effect of nicardipine (NCP) on the pharmacokinetic parameters of CsA in Sprague-Dawley rats. Each rat was administered with CsA in saline-treated group or in NCP-treated group which was pretreated with NCP (5 mg/kg/12 hours, i.p.) for 6 days. The plasma CsA concentration were analyzed by reversed HPLC: UV system at 0.5, 1, 2, 4, 6, and 8 hours after bolus injection of CsA (10 mg/kg). Pharmacokinetic parameters (mean$\pm$ SD, n=7) such as initial plasma concentration (C(0)), mean residence time (MRT), steady-state volume of distribution (Vdss), terminal half-life (t$\frac{1}{2}$($\beta$)) and plasma clearance (CLp) of CsA in each groups (saline-group vs NCP-group) were determined as follows: C(0) (5.66$\pm$ 1.98 vs 17.98$\pm$2.36, p<0.01); Vdss (2.68$\pm$ 1.6 vs 0.94 $\pm$ 0.25, p<0.01); CLp (0.53 $\pm$0.18 vs 0.21 $\pm$0.06, p<0.01). Therefore, Our results indicate that nicardipine significantly affects the pharmacokinetic parameters of cyclosporme, especially C(0), Vdss, and CLp in NCP-treated group. We suggest that the significant pharmacokinetic interaction between cyclosporine and nicardipine should be considered and cyclosporine level should be closely monitored and dosage reduction made as necessary in clinical situation that was coadministered with CsA and NCP.

• Journal of Trauma and Injury
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• v.30 no.4
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• pp.131-139
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• 2017

Purpose: Trauma systems have been shown to decrease injury-related mortality. The present study aimed to compare the mortality rates of patients with major trauma (injury severity score >15) treated before and after the establishment of a level I trauma center. Methods: During this 20-month study, participants were divided into pre-trauma center and trauma center groups, and trauma and injury severity score (TRISS) method was used to compare mortality rates during 10-month periods before and after the establishment of the trauma center (October 2013 to July 2014 vs. October 2014 to July 2015). Results: Of the 541 total participants, 278 (51.5%) visited after the establishment of the trauma center. The Z and W statistics indicated better outcomes in the trauma center group than in the pre-trauma center group (Z statistic, 2.635 vs. -0.700; W statistic, 4.640). The trauma center group also exhibited meaningful reductions in the time interval from the emergency department (ED) visit to emergency surgery (118.0 minutes vs. 142.5 minutes, p=0.020) and the interval from the ED visit to intensive care unit admission (202.0 minutes vs. 259.0 minutes, p=0.035) relative to the pre-trauma center group. Conclusions: The TRISS and multivariate analysis revealed significant improvements in survival rates in the trauma center group, compared to the pre-trauma center group.

• Preventive Nutrition and Food Science
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• v.6 no.2
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• pp.122-125
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• 2001

A potential mechanism through which the jujube extract might produce a cholesterol-lowering effect was compared with that of tangerine peel extract in vivo. Two extracts were prepared using ethanol. Male rats were fed a high cholesterol (1%, w/w) lab chow with jujube extract (1.2%) or tangerine peel extract (6.3%, w/w) for 3 weeks. Activities of hepatic HMG-CoA reductase (289.6$\pm$12.9 and 296.7$\pm$11.6 nmole/min/mg vs. 347.9$\pm$17.5 nmole/min/mg) and ACAT (554.8$\pm$18.2 and 451.7$\pm$19.4 nmole/min/mg vs. 602.6$\pm$21.4 nmole/min/mg) were significantly lowered by both supplements compared to the control group. These two supplements also substantially reduced the concentrations of plasma cholesterol (103.3$\pm$15.9 and 101.6$\pm$19.4 mg/dL vs. 141.6$\pm$18.1 mg/dL) and triglyceride (61.3$\pm$5.5 and 55.5$\pm$3.9 mg/dL vs. 96.0$\pm$4.2 mg/dL). The inhibition of HMG-CoA reductase resulting from the supplementation of jujube or tangerine extracts could count for the reduction in plasma cholesterol. Accordingly, lipid-lowering action of both supplements appears to be similar in high-cholesterol fed rats.

• YAKHAK HOEJI
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• v.53 no.3
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• pp.107-113
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• 2009

Since 2006, the Computerized Restricted Antibiotic Control Program (CRACP) has been incorporated to facilitate a more efficient approval process of vancomycin use at the Chonbuk National University Hospital. The purposes of the study were to evaluate proper use of vancomycin and to examine if there is any improvement when administering the CRACP. The use of vancomycin was retrospectively reviewed by a medical record review based on the American Society of Hospital Pharmacists (ASHP) criteria (i.e., indication, use of critical process indicators and use of outcome measurements) and compared before (Group I) and after the CRACP (Group II). Two hundred fifty six patient records were evaluated (138 in Group I and 118 in Group II). There was a statistically significant improvement in the report of justification for vancomycin use after CRACP (42.0% vs. 62.7%, p=0.001). Out of eight critical process indicators, two indicators (appropriate cultures prior to medication [68.8% vs. 85.6%, p=0.002] and serum vancomycin level measurement [0% vs. 7.6%, p=0.001]) were significantly improved after CRACP. The total incidence of adverse effects was decreased from 14.5% to 6.8%. In addition, there was a statistically significant difference in WBC count reduction within normal range (52.8% vs. 73.1%, p=0.024). The CRACP appears to be a promising approach to improve use of vacomycin in a hospital setting. However, further evaluation for the long-term period should be performed to confirm the performance of the program.