• Nuclear Engineering and Technology
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• 제44권1호
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• pp.53-60
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• 2012

The aim of this study was to explore the spatial and energy resolutions of a PET scanner that we have recently developed. The scanner, which consists of six detector modules with 1-layer LGSO crystals, has a hexagonal configuration with a faceto- face distance of 86.4 mm between two opposite PET modules; such properties facilitate the imaging of small animals. A $^{22}Na$ point source was employed to estimate horizontal and vertical spatial resolutions. To assess the energy resolution, a uniform $^{18}F$ cylindrical phantom was scanned. A software-based spectrum analysis of list-mode data was used to assign a local energy window centered on the photopeak position for every single crystal. For the image reconstruction, an ML-EM algorithm was used. The spatial resolutions at the center of the scanner were 0.99 mm in the horizontal direction and 1.13 mm in the vertical direction. The energy resolution averaged over each PMT ranged from 13.3%-14.3%, which gave an average value of 13.8%. These results show that this simple system is promising for small animal imaging with excellent spatial and energy resolutions.

• Journal of Chest Surgery
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• 제28권2호
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• pp.136-142
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• 1995

A clinical study was performed on 69 cases of isolated PDA surgically treated at the Department of Thoracic and Cardiovascular surgery of Kyung-Hee University Hospital from Mar. 1986 to Feb. 1994. Retrospective clinical analysis of these patients were as follows: 1.23 males and 46 females ranged in age from 16 days to 49 years. [mean 8.69yrs.,sex ratio M:F=1:2 2. Chief complaints were frequent URI in 44%, dyspnea on exertion in 16%,palpitation in 8%, easy fatigability in 6%, and no subjective symptoms in 26%. 3. On auscultation, typical continuous machinery murmur heard in 84%, and systolic murmur in 16% on Lt 2nd or 3rd intercostal space. 4. Simple chest x- ray showed increased pulmonary vascularity in 67%, cardiomegaly in 61%,and within normal limit in 16%. 5. EKG findings were LVH in 42%, biventricular hypertrophy in 17%, RVH in 3%, and within normal limit in 38%. 6. Echocardiogram was performed from all patient, and direct visualization of ductus in 93% 7. Cardiac catheterization was performed in 39 patients. The mean value of the results were;Differance SaO2[MPA-RV =11.03$\pm$ 5.26%,Qp/Qs=2.44$\pm$1.35,systolic pulmonary arterial pressure=40.69 $\pm$ 17.69mmHg. 8. 66 patients were operated through the left posterolateral thoracoctomy ; closure of ductus by double ligation in 43 cases, triple ligation in 23 cases.3 patients were operated by simple closure under cardiopulmonary bypass. 9. There was no death associated with the operation. The operative complications were atelectasis in 8 cases, pneumonia in 4 cases recannalization in 2 cases, and hoarseness in one case. 10. Systemic diastolic pressure was increased 8.12$\pm$ 0.13mmHg, and pulse pressure was decreased about 9.52 $\pm$ 1.87mmHg.

• 한국직업건강간호학회지
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• 제22권2호
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• pp.112-120
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• 2013

Purpose: The purpose of this study was to identify the influence of interpersonal attitude (I+, I-, U+, U-) on communication competence in care workers for frail elderly. Methods: This study was a cross-sectional survey. The data were collected from 153 care workers for frail elderly using a structured questionnaire. The data were analyzed using multiple regression with the SPSS/WIN 20.0 program. Results: The interpersonal attitude style of subjects was I+U+, and the score of communication competence was 3.53. There were significant differences in interpersonal attitude (I+, I-), and communication competence depending on age, education level, experience of personality type test (yes). Factors influencing on communication competence in care workers were interpersonal attitude (I+, I-, U+) and experience of personality type test with $R^2$ value of 48.5% (F=23.47 p<.001). The most influencing factor was I+ (${\beta}$=.36), followed by I- (${\beta}$=-.22), U+ (${\beta}$=.20), and experience of personality type test (yes) (${\beta}$=.16). Conclusion: It is needed to maintain the interpersonal attitude style (I+U+) of care workers. Continuing education program is needed for increasing communication competence especially for those fifties and over, and experienced care workers. Giving an opportunity for personality test is helpful to increase communication competence in care workers.

• Advances in concrete construction
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• 제9권5호
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• pp.449-457
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• 2020

The influence of subsequent curing on the performance of fly ash contained mortar under steam curing was studied. Mortar samples incorporated with different content (0%, 20%, 50% and 70%) of Class F fly ash under five typical subsequent curing conditions, including standard curing (ZS), water curing(ZW) under 25℃, oven-dry curing (ZD) under 60℃, frozen curing (ZF) under -10℃, and nature curing (ZN) exposed to outdoor environment were implemented. The unsteady chloride diffusion coefficient was measured by rapid chloride migration test (RCM) to analyze the influence of subsequent curing condition on the resistance to chloride penetration of fly ash contained mortar under steam curing. The compressive strength was measured to analyze the mechanical properties. Furthermore, the open porosity, mercury intrusion porosimetry (MIP), x-ray diffraction (XRD) and thermogravimetric analysis (TGA) were examined to investigate the pore characteristics and phase composition of mortar. The results indicate that the resistance to chloride ingress and compressive strength of steam-cured mortar decline with the increase of fly ash incorporated, regardless of the subsequent curing condition. Compared to ZS, ZD and ZF lead to poor resistance to chloride penetration, while ZW and ZN show better performance. Interestingly, under different fly ash contents, the declining order of compressive strength remains ZS>ZW>ZN>ZD>ZF. When the fly ash content is blow 50%, the open porosity grows with increase of fly ash, regardless of the curing conditions are diverse. However, if the replacement amount of fly ash exceeds a certain high proportion (70%), the value of open porosity tends to decrease. Moreover, the main phase composition of the mortar hydration products is similar under different curing conditions, but the declining order of the C-S-H gels and ettringite content is ZS>ZD>ZF. The addition of fly ash could increase the amount of harmless pores at early age.

• 대한기계학회논문집A
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• 제34권4호
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• pp.407-412
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• 2010

새로운 티타늄기 MMCs(W/ Ti-6Al-4V)에 대한 기계적 특성에 대한 연구를 행하여 평가한 결과를 나타내었다. HIP(hot isostatic pressing) 제조법과 RS(Rotary Swaging) 2 차 가공을 통하여 텅스텐 섬유 함유율이 각각 6, 9, 12 vol%인 W/Ti-6Al-4V MMCs 를 제작하였으며, 경도는 기존의 Ti-6Al-4V 합금과 비교하여 20-30%, 인장강도는 50%(비강도-38%) 높은 값을 얻었다. 섬유 함유율 9vol.% 에서 가장 높은 인장 값을 나타내었으며, MMCs 에서 메트릭스와 계면 사이에 생성된 확산상에 의해서 경도 및 인장강도가 향상되었다. 또한 피로 강도를 향상 시키기 위한 방법으로 메트릭스의 질적 향상을 위한 HIP 제작조건에 대한 추가적인 연구가 필요하다.

• Asian-Australasian Journal of Animal Sciences
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• 제19권2호
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• pp.209-216
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• 2006

Defatted rice polishings (DRP) was subjected to chemical treatments i.e., 0.4 N HCl, and 6% $H_2O_2$, with or without physical treatment i.e. extrusion cooking. The treated DRP was evaluated chemically and biologically using male broiler chicks (108) of approximately uniform weight, selected out of 220 chicks, previously fed on commercial diets for 7 days as a settlement period. The chicks were then divided into 36 experimental units of 3 chicks each. Each experimental diet was randomly allotted to three experimental units and fed for 10 days to broiler chicks. The experimental diets were designated as A (Commercial), B (10% HCl treated DRP), C (20% HCl treated DRP), D (10% HCl plus extruded DRP), E (20% HCl plus extruded DRP), F (10% $H_2O_2$ DRP) and G (20% $H_2O_2$ DRP), H (10% $H_2O_2$ plus extrusion DRP) and I (20% $H_2O_2$ plus extrusion DRP), J (10% untreated DRP), K (20% untreated DRP) and L (Protein free). The birds fed on diet L were used to measure the endogenous nitrogen loss. The biological evaluations of diets containing differently treated DRP were compared with a commercial feed and feeds containing untreated defatted rice polishings. It was observed that these treatments liberated bound nutrients, making them more accessible to the normal digestive enzymes and increased their apparent nutrient availability. This process probably also detoxified the anti-nutritive factors i.e. phytates, lectin, trypsin inhibitor present in DRP. The results of the feeding trials revealed that diets containing 6% $H_2O_2$ treated DRP showed better weight gain, feed consumption and utilization, protein efficiency and digestibility, biological value and net protein utilization than all other treatments.

• Journal of Korean Neurosurgical Society
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• 제37권2호
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• pp.96-100
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• 2005

Objective: The brain computed tomography(CT) is an important tool throughout the clinical course of chronic subdural hematoma(CSDH). In CT findings, the density of CSDH is different in each case. We analyze management options and results according to the density of CSDH. Methods: Seventy one patients with CSDH, who had been managed in our institute from August 2001 to December 2003, were reviewed retrospectively. The authors divided the patients into six groups according to the density of hematoma; Group A-hypodense rather than the brain parenchyma, group B-isodense, group C-hyperdense, group D-mixed with hypodense and hyperdense, group E-mixed with isodense and hypodense and group F-mixed with isodense and hypersdense. In each group, the operation method, the duration of the indwelling catheter and prognosis were analyzed. Results: The patients who showed mixed density were 39 and, those who showed single density were 32. All the patients underwent burr hole drainage for the primary choice. There was only two cases that needed additional craniotomy. The average duration of indwelling catheter was $5.40{\pm}1.91$ days. Statistically the duration was not different in each group(p-value<0.05, $x^2$ test). Three cases recurred, one in group C, another in group D, and the last in group E. It had no statistical significance due to low incidence of recurrence. Conclusion: We conclude that burr hole drainage is an acceptable primary treatment option for CSDH even though the density of hematoma is different in every single case.

• Archives of Plastic Surgery
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• 제36권1호
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• pp.19-23
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• 2009

Purpose: Platelet transplantation is a novel therapeutic strategy for acceleration of wound healing. When applying platelets, efficacy of adding thrombin to stimulate growth factor release from platelets has already been proved. However, no quantitative data of the thrombin treatment has been reported. The purpose of this study was to determine the optimal thrombin concentration to maximize growth factor release of platelets. In particular, this study was designed to quantify levels of platelet derived growth factor(PDGF)-BB, which is a major growth factor contained in the platelets, in vitro. Methods: Fresh platelets were obtained from a blood bank. They were suspended in DMEM/F - 12 and incubated with thrombin of various concentrations. The concentrations of thrombin tested were 0, 6.25, 12.5, 25, 50, 100, 200, and 400 IU/ml. After 30 minutes, 1, 3, 5, and 7 days, the levels of PDGF - BB were measured using enzyme linked immunosorbent assay. Platelets from four donors were included in this study. Each sample was tested in triplicate and the mean value was used as a data for each sample. Results: The addition of thrombin increased the level of PDGF - BB. Increases in storage time of platelets resulted in decreased levels of PDGF - BB. Higher levels of PDGF were detected in consort with increased thrombin concentrations. However, there was no significant difference between samples of 200 and 400 IU/ml concentrations. Conclusion: The results indicate that adding thrombin accelerates the release of growth factors from platelets and the optimal thrombin concentration to maximize this function is 200 IU/ml.

• 환경위생공학
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• 제23권4호
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• pp.37-44
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• 2008

In this study we developed the analytical methods for the determination of three neurotoxin; anatoxin-a, saxitoxin and neosaxitoxin using HPLC/FLD system and this analytical methods were applied to real sample; algae culture and algae extracts. For the HPLC/FLD analysis of anatoxin-a samples were concentrated on WCX(Weak Cation Exchanger) SPE and then anatoxin-a in concentrate was derivatized with NBD-F solution. Supernatant was injected on HPLC system. For the HPLC/FLD analysis of saxitoxin and neosaxitoxin samples were separated on the column and then derivatizied by post column reactor for fluorescen detection. For post column reaction of saxitoxin we feed two kinds of reaction solution; Oxidizing Reagent of which composition was periodic acid(7mM) in 50mM potassium phosphate buffer, pH 9 and acidifying reagent of which Composition was 0.5M acetic acid. The LOD value for anatoxin-a, saxitoxin and neosaxitoxin in HPLC/FLD method was 24.3 ng. $35{\mu}g/L$, $27{\mu}g/L$ respectively. We determined the anatoxin-a content of lyophilized anabaena flos-aquae and $20{\mu}g/g$ d.w. of anatoxin-a was detected. We analyzed saxitoxin and neosaxitoxin in algae culture media and extracts of lypopyllized algal cell cultured and that of Deachung reservior. Saxitoxin and neosaxitoxin in real sample were below the limit of detection. Although there are various water treatment processes for removing neurotoxins were suggested no process give simultaneous and complete removal of neurotoxins. It was cocluded that nanofiltration which reject material by size can be a process for removal of neurotoxins.

• 한국식품영양학회지
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• 제23권3호
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• pp.419-427
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• 2010

The focus of the current study was to investigate the physicochemical properties of a corn starch-sponge matrix prepared at a low concentration below gel forming by freeze-drying. The effect of variables(starch concentration, heating temperature, and heating hold time) on the physicochemical properties of the samples was analyzed by response-surface methodology. Regression models on the properties of samples such as hardness, springiness, and water solubility index(WSI) showed high correlation coefficients(r>0.95) and significant F values, but regression models for the other properties(swelling power, apparent viscosity, reducing sugar content, and digestibility) showed them to have relatively low significance. Sample hardness of sample showed the highest value at condition of $90^{\circ}C$ and 5%, whereas springiness was at a maximum at $130^{\circ}C$ and 5%. Also, at 1% of starch concentration, mechanical properties were greatly decreased as the relative humidity increased, compared with the 3% and 5%, especially in the hardness of samples. The WSI showed an increasing trend with heating temperature regardless of starch concentration. Overall, the physicochemical properties of freeze-dried corn starch-sponge matrix were influenced much more by starch concentration and heating temperature than by heating hold time. The results of this study show that the basic properties of freeze-dried corn starch-sponge matrix can be used for the specific food applications or as a functional material for its stability.