• Quality Improvement in Health Care
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• v.4 no.1
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• pp.36-49
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• 1997

Background : Hypertension is one of the most important risk factors of the cerebrovascular accident and coronary artery disease which are the major causes of mortality in Korea. In Korea, the quality of care provided by office-based physicians has not been evaluated formally. The purpose of this study is to assess the quality of hypertension management of office-based physicians. Method : Self-administered questionnaires were mailed to the office-based physicians with the speciality of internal medicine, general surgery, family medicine, and general practitioners. Among 2,045 physicians, 981 doctors(48.0%) replied the questionnaires. Contents of questionnaires were based on the recommendation from the JNC-V report(the Fifth Report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure), and included the criteria of diagnosis, treatment, follow-up interval, and other characteristics of physicians(age, sex, type of speciality, and location of practice). Results : Eighty four percent of the office-based physicians made diagnosis of hypertension with less than 3 times of blood pressure measurements. The performance rate of required examination for hypertensives was very low in most items. Rate of fundoscopic examination is the lowest one among them(5.9%). The performance rate of laboratory examination was also low in most items. Internists tended to order more frequent laboratory examinations than any other type of physicians. Only 11.4% of the physicians did appropriate treatments for the mild hypertension case. The antihypertensives selected by the physicians as a first line drug were in the order of beta blocker(26.4%), calcium channel blocker(23.4%), diuretics(23.1%), ACE inhibitors(14.3%). The visit interval for established hypertensives was very short. Proportion of physicians with follow-up interval longer than 4 weeks was only 4.3%. Conclusions : The overall quality of hypertension management of office-based physicians in Korea is very problematic in many aspects. So further investigations to find out the reasons of low quality arid quality of care should be initiated.

• Journal of radiological science and technology
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• v.41 no.2
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• pp.141-148
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• 2018

This study examined the properties of photons and the dose distribution in a human body via a simulation where the total body irradiation(TBI) is performed on a pediatric anthropomorphic phantom and a child size water phantom. Based on this, we tried to find the optimal photon beam energy and material for beam spoiler. In this study, MCNPX (Ver. 2.5.0), a simulation program based on the Monte Carlo method, was used for the photon beam analysis and TBI simulation. Several different beam spoiler materials (plexiglass, copper, lead, aluminium) were used, and three different electron beam energies were used in the simulated accelerator to produce photon beams (6, 10, and 15 MeV). Moreover, both a water phantom for calculating the depth-dependent dosage and a pediatric anthropomorphic phantom for calculating the organ dosage were used. The homogeneity of photon beam was examined in different depths for the water phantom, which shows the 20%-40% difference for each material. Next, the org an doses on pediatric anthropomorphic phantom were examined, and the results showed that the average dose for each part of the body was skin 17.7 Gy, sexual gland 15.2 Gy, digestion 13.8 Gy, liver 11.8 Gy, kidney 9.2 Gy, lungs 6.2 Gy, and brain 4.6 Gy. Moreover, as for the organ doses according to materials, the highest dose was observed in lead while the lowest was observed in plexiglass. Plexiglass in current use is considered the most suitable material, and a 6 or 10 MV photon energy plan tailored to the patient condition is considered more suitable than a higher energy plan.

• Korean Journal of Materials Research
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• v.20 no.7
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• pp.374-378
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• 2010

$MgTiO_3$ thin films were prepared by r.f. magnetron sputtering in order to prepare miniaturized NPO type MLCCs. $MgTiO_3$ films showed a polycrystalline structure of ilmenite characterized by the appearance of (110) and (202) peaks. The intensity of the peaks decreased with an increase in the chamber pressure due to the decrease of crystallinity which resulted from the decrease of kinetic energy of the sputtered atoms. The films annealed at $600^{\circ}C$ for 60min. showed a fine grained microstructure without micro-cracks. The grain size and roughness of the $MgTiO_3$ films decreased with the increase of chamber pressure. The average surface roughness was 1.425~0.313 nm for $MgTiO_3$ films prepared at 10~70 mTorr. $MgTiO_3$ films showed a dielectric constant of 17~19.7 and a dissipation factor of 2.1~4.9% at 1MHz. The dielectric constant of the films is similar to that of bulk ceramics. The dielectric constant and the dissipation factor decreased with the increase of the chamber pressure due to the decrease of grain size and crystallinity. The leakage current density was $10^{-5}\sim10^{-7}A/cm^2$ at 200kV/cm and this value decreased with the increase of the chamber pressure. The small grain size and smooth surface microstructure of the films deposited at high chamber pressure resulted in a low leakage current density. $MgTiO_3$ films showed a near zero temperature coefficient and satisfied the specifications for NPO type materials. The dielectric properties of the $MgTiO_3$ thin films prepared by sputtering suggest the feasibility of their application for MLCCs.

• Archives of Reconstructive Microsurgery
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• v.13 no.2
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• pp.107-116
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• 2004

Flaps are necessary, when important structures such as bone, tendon, nerve and vessel are exposed. Arterialized venous free flap is suited to the coverage of finger and hand because the thickness of venous flap is thin. Authors performed 65 cases arterialized venous free flap for the soft tissue reconstruction of the hand and finger. The size of donor defect were from $1{\times}1cm\;to\;7{\times}12cm$. The mean flap area was $9.1cm^2$. The recipient sites were finger tip in 34 cases, finger shaft in 29 cases and hand in 2 cases. The donor sites were volar aspect of distal forearm in 40 cases, thenar area in 17 cases and foot dorsum in 6 cases. The types of arterialized venous free flap were A-A type in 4 cases and A-V type in 61 cases. The length of afferent vein was from 0.5 cm to 3 cm (mean 1.7 cm) and efferent vein was from 1 cm to 10 cm (mean 2.2 cm). 58 flaps(89.2%) survived eventually. 42 flaps(64.6%) survived totally without any complication. 8 flaps(12.3%) showed the partial necrosis but they were healed without any additional operations. 8 flaps (12.3%) showed the partial necrosis requiring the additional skin graft. We had a satisfactory result by using arterialized venous free flap for the soft tissue reconstruction of finger and hand. We believe that volar aspect of distal forearm, thenar area, foot dorsum are suited as a donor site and the short length of the flap pedicle, the strong arterail inflow affect the survival rate of arterialized venous free flaps.

• Journal of Pharmaceutical Investigation
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• v.40 no.6
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• pp.353-356
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• 2010

Although liposomes have been applied as drug delivery systems in various fields, the usage was limited due to the low encapsulation efficiency compared to other carrier systems. Here, cationic liposomes were prepared by mixing 1,2-dioleoyl-3-trimethylammoniopropane (DOTAP) as a cationic lipid, 1,2-dioleoyl-sn-glycerol-phosphoethanolamine (DOPE) and cholesterol (CH), and the liposomes were hydrated by varying the aqueous phases such as phosphate-buffered saline (PBS), 5% dextrose, and 10% sucrose in order to improve the encapsulation efficiency of bovine serum albumin (BSA). The particle size and zeta potential were determined by dynamic light scattering method and in vitro release patterns were investigated by spectrophotometry. Particle size and zeta potential of liposomes were varied depending on the ratio of DOTAP/DOPE/CH in range of 270-350 nm and 0.8-9.7 mV, respectively. Moreover, the addition of polyethylene glycol (PEG) improved the encapsulation efficiency from 37% to 43% as well as reduced particle sizes of liposomes while the liposomes were hydrated in PBS. When the liposomes were hydrated with 10% sucrose, the encapsulation efficiency of BSA was higher than any other groups. Whereas PBS was used as hydration solution, lower encapsulation efficiency was obtained compared with other groups. More than 60% of BSA was released from the liposomes hydrated with 10% sucrose; thereafter another 20% of BSA was released. Therefore, release pattern of BSA from cationic liposomes was extended release in this study. From the results, cationic liposomes dispersed in 10% sucrose would be potential carrier with high encapsulation efficiency.

• Journal of Ginseng Research
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• v.36 no.1
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• pp.78-85
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• 2012

Endothelial progenitor cells (EPC) are a population of cells that circulate in the blood stream. They play a role in angiogenesis and, therefore, can be prognostic markers of vascular repair. Ginsenoside $Rg_3$ prevents endothelial cell apoptosis through the inhibition of the mitochondrial caspase pathway. It also affects estrogen activity, which reduces EPC senescence. Sun ginseng (SG), which is heat-processed ginseng, has a high content of ginsenosides. The purpose of this study was to investigate the protective effects of SG on senescence-associated apoptosis in EPCs. In order to isolate EPCs, mononuclear cells of human blood buffy coats were cultured and characterized by their uptake of acetylated low-density lipoprotein (acLDL) and their binding of Ulex europaeus agglutinin I (ulex-lectin). Flow cytometry with annexin-V staining was performed in order to assess early and late apoptosis. Senescence was determined by ${\beta}$-galactosidase (${\beta}$-gal) staining. Staining with 4'-6-Diamidino-2-phenylindole verified that most adherent cells (93${\pm}$2.7%) were acLDL-positive and ulex-lectin-positive. The percentage of ${\beta}$-gal-positive EPCs was decreased from 93.8${\pm}$2.0% to 62.5${\pm}$3.6% by SG treatment. A fluorescence-activated cell sorter (FACS) analysis showed that 4.9% of EPCs were late apoptotic in controls. Sun ginseng decreased the apoptotic cell population by 39% in the late stage of apoptosis from control baseline levels. In conclusion, these results show antisenescent and antiapoptotic effects of SG in human-derived EPCs, indicating that SG can enhance EPC-mediated repair mechanisms.

• Journal of Plant Biotechnology
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• v.48 no.2
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• pp.86-92
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• 2021

The present study aimed to evaluate the initiation, proliferation potential, and mass clonal production ability of a micropropagation system for banana through tissue culture. A total of 60 explants were cultured on basal media supplemented with various concentrations of BAP and NAA. Banana plants regenerated on MS basal medium (control) without the addition of BAP + NAA showed a significantly (P < 0.05) lower survival rate with no signs of shoots up to the end of the experimental period. The results further revealed that the performance in MSS-XI medium was almost 89%, followed by MSS-IX and MSS-X media, both of which showed performance up to 88%. In contrast, the performance in the MSS-XVI medium was less than 60%, at the less duration of time and highly shoot induction detected at MSS-XIII medium. The maximum number of shoots (4.9) was observed in the medium supplemented with growth adjuster MSS-XI, followed by the MSS-XII medium (4.5). Surprisingly, the best performance was observed for the MSR-VII medium approximately 16 days after initiation, while the lowest performance was observed with MSR-XI (approximately 31 days). The maximum rooting percentage (98%) was observed in the MSR-V to MSR-VIII media (98%), while the minimum rooting percentage was observed in MSR-XI (approximately 45%).

• Korean Journal of Ecology and Environment
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• v.55 no.4
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• pp.368-375
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• 2022

Gut contents analysis is essential to predict the impact of organisms on food source changes due to variations of the habitat environment. Previous studies of gut content analysis have been conducted using traditional methods, such as visual observation. However, these studies are limited in analyzing food sources because of the digestive process in gut organ. DNA metabarcoding analysis is a useful method to analyze food sources by supplementing these limitations. We sampled marine fish of Pennahia argentata, Larimichthys polyactis, Crangon affinis, Loligo beka and Sepia officinalis from Gwangyang Bay and Yeosu fisheries market for analyzing gut contents by applying DNA metabarcoding analysis. 18S rRNA v9 primer was used for analyzing food source by DNA metabarcoding. Network and two-way clustering analyses characterized the relationship between organisms and food sources. As a result of comparing metabarcoding of gut contents for P. argentata between sampled from Gwangyang Bay and the fisheries market, fish and Copepoda were analyzed as common food sources. In addition, Decapoda and Copepoda were analyzed as common food sources for L. polyactis and C. affinis, respectively. Copepoda was analyzed as the primary food source for L. beka and S. officinalis. These study results demonstrated that gut contents analysis using DNA metabarcoding reflects diverse and detailed information of biological food sources in the aquatic environment. In addition, it will be possible to provide biological information in the gut to identify key food sources by applying it to the research on the food web in the ecosystem.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.6
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• pp.740-750
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• 2006

Statement of problems. In an attempt to reduce screw loosening, dry lubricant coatings such as pure gold or tefron have been applied to the abutment screw. However, under repeated tightening and loosening procedures, low wear resistance and adhesion strength of coating material produced free particles on the surface of abutment screw and increased frictional resistance resulting in screw tightening problems. Purpose. The aim of this study was to compare friction coefficient, adhesion strength, vickers hardness and evaluate coating surface of titanium alloy specimens coated with TiN(titanium nitride), ZrN(zirconium nitride) and WC(tungsten carbide). Material and method. Titanium alloy(Ti-6Al-4V) discs of 12mm in diameter and 1mm in thickness divided into 4 groups. TiN, ZrN and WC was coated for the specimens of 3 groups respectively, and those of 1 group were not coated. Each group was made up of 4 specimens. In this study, sputtering method was used among the PVD(Physical Vapor Deposition) techniques available for TiN, ZrN and WC coatings. Friction coefficient, adhesion strength, vickers hardness and coating surface of 4 groups were measured. Results. 1. For all three coating conditions, friction coefficient was significantly decreased. Especially, ZrN coated surface showed the lowest value. $TiN(0.39{\pm}0.02)$, $ZrN(0.24{\pm}0.01)$, $WC(0.31{\pm}0.03)$. 2. TiN coating showed the highest adhesion strength, however ZrN coating had the lowest value. $TiN(25.3N{\pm}1.6)$, $ZrN(14.8N{\pm}0.6)$, $ WC(18.4N{\pm}0.7)$. 3. Vickers hardness of all three coatings was remarkably increased as compared with that of none coated specimen. TiN coating had the highest Vickers hardness, however WC coating showed the lowest value. $TiN(1865.2{\pm}33.8)$, $ZrN(1814.4{\pm}18.6)$, $WC(1008.5{\pm}35.9)$. 4. The ZrN or WC coated specimen showed a homogeneous and smooth surface, however the rough surface with defects was observed for TiN coating. Conclusions. When TiN, ZrN and WC coating applied to the abutment screw, frictional resistance would be reduced, as a result, the greater preload and prevention of the screw loosening could be expected.

• Nutrition Research and Practice
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• v.11 no.6
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• pp.470-478
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• 2017

BACKGROUND/OBJECTIVE: Orostachys japonicus A. Berger (Crassulaceae) has been used in traditional herbal medicines in Korea and other Asian countries to treat various diseases, including liver disorders. In the present study, the anti-fibrotic effects of O. japonicus extract (OJE) in cellular and experimental hepatofibrotic rat models were investigated. MATERIALS/METHODS: An in vitro hepatic stellate cells (HSCs) system was used to estimate cell viability, cell cycle and apoptosis by MTT assay, flow cytometry, and Annexin V-FITC/PI staining techniques, respectively. In addition, thioacetamide (TAA)-induced liver fibrosis was established in Sprague Dawley rats. Briefly, animals were divided into five groups (n = 8): Control, TAA, OJE 10 (TAA with OJE 10 mg/kg), OJE 100 (TAA with OJE 100 mg/kg) and silymarin (TAA with Silymarin 50 mg/kg). Fibrosis was induced by treatment with TAA (200 mg/kg, i.p.) twice per week for 13 weeks, while OJE and silymarin were administered orally two times per week from week 7 to 13. The fibrotic related gene expression serum biomarkers glutathione and hydroxyproline were estimated by RT-PCR and spectrophotometry, respectively, using commercial kits. RESULTS: OJE (0.5 and 0.1 mg/ mL) and silymarin (0.05 mg/mL) treatment significantly (P < 0.01 and P < 0.001) induced apoptosis (16.95% and 27.48% for OJE and 25.87% for silymarin, respectively) in HSC-T6 cells when compared with the control group (9.09%). Further, rat primary HSCs showed changes in morphology in response to OJE 0.1 mg/mL treatment. In in vivo studies, OJE (10 and 100 mg/kg) treatment significantly ameliorated TAA-induced alterations in levels of serum biomarkers, fibrotic related gene expression, glutathione, and hydroxyproline (P < 0.05-P < 0.001) and rescued the histopathological changes. CONCLUSIONS: OJE can be developed as a potential agent for the treatment of hepatofibrosis.