• Journal of Powder Materials
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• v.24 no.1
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• pp.6-10
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• 2017

This study investigates the main growth mechanism of InP during InP/ZnS reaction of quantum dots (QDs). The size of the InP core, considering a synthesis time of 1-30 min, increased from the initial 2.56 nm to 3.97 nm. As a result of applying the proposed particle growth model, the migration mechanism, with time index 7, was found to be the main reaction. In addition, after the removal of unreacted In and P precursors from bath, further InP growth (of up to 4.19 nm (5%)), was observed when ZnS was added. The full width at half maximum (FWHM) of the synthesized InP/ZnS quantum dots was found to be relatively uniform, measuring about 59 nm. However, kinetic growth mechanism provides limited information for InP / ZnS core shell QDs, because the surface state of InP changes with reaction time. Further study is necessary, in order to clearly determine the kinetic growth mechanism of InP / ZnS core shell QDs.

• Proceedings of the Korea Society of Design Studies Conference
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• 2001.10a
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• pp.9.1-9
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• 2001

Concerning the development of suitable healthcare equipment for a aged people at their homes in order to reduce the labor and increase the efficiency in the homehelpers' work, we conducted a study on the actual conditions of healthcare in Kyoto city (healthcare in taking a meal and excretion, moving and taking a bath by using a hand-powered lift, moving by a wheelchair, shower carrier healthcare, assistance in body care and housework) by digital video filming, interviews and layout investigations. On the base of those investigations by using methods for analysis of video pictures, we divided the healthcate work into scenes and e exctracted the main problems in terms of health care equipment, information, environment, healthcare skills, mental burden, social s system, family burden, ete. Furthermore the questionnaire survey of home helpers (18 persons - 50% answers) clarified that more than half of them have lumbago pains and the biggest load in the everyday healthcare c comes from moving the patients or getting them into or out of t the equipment for moving. Finally we considered concrete proposals appropriate for each h healthcare scene image, based on evaluation toward efficiency (design guidelines) for suitable healthcare equipment for aged people at their homes: 1) Design toward a proper posture 2) Design toward self-help possibility 3) Design toward patient active participation 4) Design toward rationality of the whole process 5) Design toward place-appropriate healthcare equipment 6) Design toward healing of mind 7) Good level of healthcare skills 8) Economic, systematic rationality

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.5
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• pp.305-310
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• 2010

The human $ether$-$a$-$go$-$go$-related gene ($hERG$) channel is important for repolarization in human myocardium and is a common target for drugs that prolong the QT interval. We studied the effects of two antipsychotics, tiapride and sulpiride, on hERG channels expressed in $Xenopus$ oocytes and also on delayed rectifier $K^+$ currents in guinea pig cardiomyocytes. Neither the amplitude of the hERG outward currents measured at the end of the voltage pulse, nor the amplitude of hERG tail currents, showed any concentration-dependent changes with either tiapride or sulpiride ($3{\sim}300{\mu}M$). However, our findings did show that tiapride increased the potential for half-maximal activation ($V_{1/2}$) of HERG at $10{\sim}300{\mu}M$, whereas sulpiride increased the maximum conductance ($G_{max}$) at 3, 10 and $100{\mu}M$. In guinea pig ventricular myocytes, bath applications of 100 and $500{\mu}M$ tiapride at $36^{\circ}C$ blocked rapidly activating delayed rectifier $K^+$ current ($I_{Kr}$) by 40.3% and 70.0%, respectively. Also, sulpiride at 100 and $500{\mu}M$ blocked $I_{Kr}$ by 38.9% and 76.5%, respectively. However, neither tiapride nor sulpiride significantly affected the slowly activating delayed rectifier $K^+$ current ($I_{Ks}$) at the same concentrations. Our findings suggest that the concentrations of the antipsychotics required to evoke a 50% inhibition of IKr are well above the reported therapeutic plasma concentrations of free and total compound.

• Journal of Chest Surgery
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• v.22 no.2
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• pp.179-190
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• 1989

The experimental study for extracorporeal preservation of the heart-lung preparation by autoperfusion system was performed in 10 dogs. Under intravenous Pentothal endotracheal anesthesia bilateral thoracotomies were performed. A 24F cannula connected to a plastic reservoir bag located 100 cm above the level of the heart was introduced into the aortic arch. Left subclavian, innominate artery, and descending aorta were ligated and divided. Both vena cavae were ligated and divided after the bag was half filled with blood. A 24F catheter inserted into right atrium and connected to the plastic bag in order to keep constant the preload. The thoracic trachea was intubated and the lungs were ventilated. The heart-lung preparations were removed en bloc and floated in a $34^{\circ}C$ bath of Hartmann solution. The preparations were observed for from 2 hours to 8 hours, with the average of 5.2 hours. Hemodynamic and hematologic variables were measured during preharvest and autoperfusion. The pH revealed severe respiratory alkalosis due to very low $PaCO_2$ during autoperfusion ; $PaO_2$ remained constant for 130-140 mmHg; $A-aDO_2$ increased markedly. The static inspiratory pressure [SIP] at late autoperfusion [6hr] increased significantly as compared with at early autoperfusion [2hr]. There was no difference between white blood cell counts from right atrium and those of left atrium. Heart rates remained constant for 110-120/min; cardiac outputs maintained to approximately 0.6L/min; mean aortic pressures, 75 mmHg; mean pulmonary arterial pressures, 15-18 mmHg; mean right atrial pressures, 9-13 mmHg; mean left atrial pressures, 12 mmHg lower than those of right atrium. Serum Na maintained with normal range during autoperfusion; K increased significantly; Ca decreased progressively. Hemoglobin and hematocrit decreased significantly during autoperfusion. The study demonstrated that stable hemodynamics could be maintained throughout the experiment and the preparation of the lung seemed to be inadequate, especially after 3-4 hours, such as high $A-aDO_2$, increased SIP, and scattered atelectasis and edema in their gross appearances.

• Journal of Preventive Medicine and Public Health
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• v.38 no.1
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• pp.16-24
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• 2005

Objectives : To help develop strategies to cope with the changes arising from the rapid aging process by predicting the determining factors of intention to actual use of the charged long-term care services for elderly as perceived by the middle aged who play the major role of supports. Methods : Subjects were the parents (men 177, women 507) in their 40s of the students selected from a university of Busan city. A questionnaire survey was conducted for 4 weeks in October 2003 about the knowledge for long-term care service, the intention of actual use, and the preferences about the type of service suppliers. Data analysis was performed with frequency, chi-square test, and t-test using SPSS program (ver 10.0K), along with data mining using decision tree of Enterprise Miner V8.2 by SAS. Results : About half of the subjects (53.7%) had the actual experiences of elderly supports. Intentions to use the charged services were relatively high in home visiting nursing care service (40.1%) and long-term care facilities service (40.4%), and were influenced by previous knowledge about the services. The intentions were stronger in women, those with higher education, and those with greater income levels. Actual elderly supports were mostly (80%) done by women, and the perceived burdens for the supports were bigger in women and those of lower socioeconomic level. Desired charges were about 10,000 won for the bath service, 20,000 won for the rests services per day, and about 500,000 won for the long-term care facilities service per month. From the result of decision tree analysis, the job professionalism was the most important determining factor of intention to actual use of the services with validation as $63{\sim}71%$. Health and welfare mixed type facilities were preferred, and the most important consideration was the level of professionalism. Conclusions : Intention to actual use of the charged services was largely determined by the aspects of time and cost. Polices to increase the number of service suppliers and to decrease the burdens perceived by actual supporters were strongly recommended.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.166-166
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• 2003

Muskmelon(Cucumis melo L.)은 독특한 향기와 높은 당도로 각광받고 있는 과일로 주로 지중해, 아시아, 북유럽과 미주지역에서 광범위하게 재배되고 있으며 우리나라에서는 주로 시설 내에서 재배되고 있다. 점차 그 수요가 증가하고 있는 fresh-cut제품은 유통, 저장 기간 동안 제품의 신선함 유지가 요구된다. 본 연구에서는 가공 전 열처리가 fresh-cut muskmelon의 품질에 미치는 영향과 최적 열처리 조건을 조사하였다. Half-cut melon을 대상으로 blanching 온도 설정을 위한 예비 실험을 한 결과 5$0^{\circ}C$ 열처리한 구가 향, 연화 저해 정도, 그리고 전체적인 기호도에 대한 관능평가 가장 우수하였다. 이를 바탕으로 5$0^{\circ}C$의 water bath상에서 whole melon을 10, 20, 30, 40분 blanching하여 5$^{\circ}C$에서 24시간 저장한 후 cork borer를 이용하여 cylinder 형의 fresh-cut melon을 가공하였다. 가공한 melon은 5$^{\circ}C$에서 6일 저장하면서 L-value, chroma-value, soluble solid, pH, 경도, 호흡 변화 등을 통해 품질변화를 측정하였다. 저장 6일후 L-value의 변화는 대조구에서 가장 크게 나타났으며, chroma-value는 저장 시간이 경과함에 따라 감소하였으며 10분 열처리 한 구에서 변화정도가 가장 낮게 나타났다. 수용성 고형분 함량은 저장기간의 경과에 따른 큰 변화는 없었으나 40분 열처리한 구에서 수용성 고형분 함량이 가장 낮았으며 20, 30분 열처리한 구에서 높게 나타났다. 저장 중 fresh-cut melon의 pH는 증가하는 경향을 보였으며 10분 열처리한 구에서 가장 낮게 나타났다. 호흡변화는 저장 기간이 경과함에 따라 $O_2$는 감소하고 $CO_2$는 증가했으며 특히 20분 열처리한 구에서 $CO_2$가 크게 증가한 것으로 나타났다. 증가 정도가 가장 크게 나타났다. 열처리한 fresh-cut melon의 hardness는 저장 3일 후 대조구와 40분 열처리 구에서 가장 낮아 연화현상을 확인했으며 20분 열처리구에서 초기 hardness가 유지되는 것으로 확인했다. 따라서 fresh-cut melon을 위한 가공 전 열처리를 위해서는 5$0^{\circ}C$에서 10분 열처리가 품질 변화를 유지하는데 적당하다고 판단된다.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.1
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• pp.255-264
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• 1991

The purpose of this study was to evaluate the effect of the shear bond strength between porcelain laminate veneer and enamel according to the surface treatment and thermocycling. Group I, as a control group, was sandblasted only; group II was sandblasted and etched; group III was sandblasted and silane treated; and group IV was sandblasted, etched and silane treated. A porcelain block was placed onto the etched enamel under a 150g static load and the bonded site was light-cured from 4 directions for 1 minute each. The 72 bonded specimens were stored in water at $37^{\circ}C$ for 1 day. Half of each group were thermocycled at $4^{\circ}C$ and $60^{\circ}C$ for 100 cycles with a dwelling time in each bath of 1 min. Following thermocycling, the specimens were installed in an Instron universal testing machine and the shear bond strength was measured. After the specimens were fractured, the fractured surfaces were examined with SEM. The obtained results were as follows : 1. The shear bond strength of the sandblasted and etched and silane treated group(Group IV) was the strongest of all, and the shear bond strengths between the sandblasted group(Group I) and the sandblasted and silane treated group(Group III) were not statistically different(p>0.05). 2. When the shear bond strength was measured after thermocycling, only the sandblasted, etched and silane treated group(Group IV) was statistically different(p<0.05). 3. The scanning electron microscopic views of the fractured surfaces show more irregularities and more resin fragments in the etched group than in the unetched group. 4. The scanning electron microscopic views of the fractured surfaces show a more delicate surface after thermocycling and after silane treatment than before thermocycling and before silane treatment.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.1
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• pp.25-31
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• 2000

ATP-sensitive potassium channels ($K_{ATP}$ channels) play an important role in insulin secretion from pancreatic beta cells. We have investigated the effect of propofol on $K_{ATP}$ channels in cultured single pancreatic beta cells of rats. Channel activity was recorded from membrane patches using the patch-clamp technique. In the inside-out configuration bath-applied propofol inhibited the $K_{ATP}$ channel activities in a dose-dependent manner. The half-maximal inhibition dose (ED50) was $48.6{\pm}8.4\;{\mu}M$ and the Hill coefficient was $0.73{\pm}0.11.$ Single channel conductance calculated from the slope of the relationship between single channel current and pipette potential $(+20{\sim}+100\;mV)$ was not significantly altered by propofol $(control:\;60.0{\pm}2.7\;pS,\;0.1\;mM\;propofol:\;58.7{\pm}3.5\;pS).$ However, mean closed time was surely increased. Above results indicate that propofol blocks the $K_{ATP}$ channels in the pancreatic beta cells in the range of its blood concentrations during anesthesia, suggesting a possible effect on insulin secretion and blood glucose level.

• Journal of Animal Environmental Science
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• v.5 no.3
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• pp.189-196
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• 1999

Anaerobic digestion is a naturally occuring microbial process involving the decomposition of organic materials such as livestock manure. This study explores the effect of the operating conditions, HRT (Hydraulic Retention Time) and feeding frequency on treatment efficiency for digestion of pig slurry, which has been one of most difficult organic waste for proper treatment in livestock production industry in Korea at the present time. The pilot-scale CSTR of 5 m3 in volume was designed. manufactured, and operated at the temperature of 35$\pm$1$^{\circ}C$. The digester was designed to hydraulically stir for complete mixing and to supply heat from the water bath to maintain mesophilic temperature. The HRT of the digester for Test 1 and Test 2, and Test 3 was set for 17 days and 13 days respectively and pig slurry was fed once a day with 300$\ell$ each for Test 1 and Test 3, while twice with 150$\ell$each for Test 2. Test 2 showed better performance by increase of 4% in VS removal efficiency and 5% in biogas production rate. This is mainly attributed to smaller temperature drop by feeding frequently with half amount, which eventually led to lesser impact on anaerobic mocrobes in the digester. Test 2 maintained optimum pH 7.8 which uplifted the activaton of sulfur-reduction bacteria, alkalinity of around 4,000mg/$\ell$, VA of over 3,000mg/$\ell$ for whole period of experiment. Further research may require to provide the practical operation strategy of anaerobic treatment system for treatment of pig slurry.

• The Korean Journal of Nuclear Medicine
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• v.31 no.4
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• pp.427-432
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• 1997

Re-188 is useful candidate for therapeutic radionuclide because it has a physical half life of 17 hours, contains beta emissions suitable for therapy(maximum energy 2.12MeV) and emits a gamma ray that is suitable for quantitative diagnostic scanning(155keV). To use Re-188 as a radionuclide compound of angioplasty balloon radiotherapy, we investigated the labelling method and biodistribution of Re-188-DTPA We postulated that labeled Re-188-DTPA is preferable because it would be excreted via urinary system more easily than other compounds. To label Re-188 with DTPA, 1ml of 222MBq(6mCi) of Re-188 was added to DTPA solution(DTPA 20mg, $SnCl_2{\cdot}2H_2O$ 10mg, pH 3.5) and boiled at $100^{\circ}C$ for 120min in water bath. pH was adjusted to 5 with 2.3% sodium acetate. Labeling efficiency was measured using TLC-SG(acetone, saline). We evaluated biodistribution of Re-188-DTPA in sacrificed mice at 10 and 60 minutes after injection. We acquired images of kidneys, and drew time-activity curves in normal dogs and rats and calculated Tmax and Tl/2 in rats. The labelling efficiency was 95.7% on average. Labelling of Re-188-DTPA was.stable(90% after 5hours) in vitro at room temperature. According to time-activity curves of dogs and rats, it took 15 to 20 minutes after injection for Re-188-DTPA to be washed out through kidneys. In conclusion, Re-188-DTPA was successfully labeled, Re-188-DTPA was stable in vitro and was excreted early via kidneys in animals. We could recommend Re-188-DTPA as radionuclide of potential use in angioplasty balloon radiotherapy.