• 한국축산식품학회지
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• 제41권5호
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• pp.816-825
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• 2021

This study aims to validate a fast method of simultaneous analysis of 365 LCamenable and 142 GC-amenable pesticides in hen eggs by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS), respectively, operating in multiple reaction monitoring (MRM) acquisition modes. The sample preparation was based on quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction. Key method performance parameters investigated were specificity, linearity, limit of quantification (LOQ), accuracy, precision and measurement uncertainty. The method was validated at two spiking levels (10 and 50 ㎍/kg), and good recoveries (70%-120%) and relative standard deviations (RSDs) (≤20) were achieved for 92.9% of LC-amenable and 86.6% of GC-amenable pesticide residues. The LOQs were ≤10 ㎍/kg for 94.2% of LC-amenable and 92.3% of GC-amenable pesticides. The validated method was further applied to 100 egg samples from caged hens, and none of the pesticides was quantified.

• Journal of Microbiology and Biotechnology
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• 제27권8호
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• pp.1441-1448
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• 2017

Antibacterial compounds are widely used in the treatment of human and animal diseases. The overuse of antibiotics has led to a rapid rise in the prevalence of drug-resistant bacteria, making the development of new antibacterial compounds essential. This study focused on developing a fast and easy method for identifying marine bacteria that produce antibiotic compounds. Eight randomly selected marine target bacterial species (Agrococcus terreus, Bacillus algicola, Mesoflavibacter zeaxanthinifaciens, Pseudoalteromonas flavipulchra, P. peptidolytica, P. piscicida, P. rubra, and Zunongwangia atlantica) were tested for production of antibacterial compounds against four strains of test bacteria (B. cereus, B. subtilis, Halomonas smyrnensis, and Vibrio alginolyticus). Colony picking was used as the primary screening method. Clear zones were observed around colonies of P. flavipulchra, P. peptidolytica, P. piscicida, and P. rubra tested against B. cereus, B. subtilis, and H. smyrnensis. The efficiency of colony scraping and broth culture methods for antimicrobial compound extraction was also compared using a disk diffusion assay. P. peptidolytica, P. piscicida, and P. rubra showed antagonistic activity against H. smyrnensis, B. cereus, and B. subtilis, respectively, only in the colony scraping method. Our results show that colony picking and colony scraping are effective, quick, and easy methods of screening for antibacterial compound-producing bacteria.

• 국제초고층학회논문집
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• 제11권3호
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• pp.227-240
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• 2022

Under the Korean Enforcement Decree of the Building Act, all high story apartment houses more than 5 stories high are mandated to install a fire evacuation system to ensure safe evacuation from fire accidents and providing quick and easy bidirectional escape route when main entrance is blocked by flame or toxic smoke. However, the current fire evacuation system shows a lack of understanding from residents and thus is widely ignored for having insufficient safety functions, especially vis-à-vis fire emergencies. Studies have found that an alternative evacuation method, the escapable fire evacuation system, has been analyzed for safety evaluation compared with the conventional passive fire escape system and can bring efficient and safer solutions, providing high rise residents escape from fire accidents. Evaluation for safety evacuation has been performed by the Fire Dynamics Simulation and applying Pathfinder simulation. This resulted in providing appropriate escape routes within the safety escape time and allowed for people in high rise building fires to get to safety.

• 분석과학
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• 제36권5호
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• pp.205-215
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• 2023

In the present study, an analytical method was proposed for detecting trifluralin in aquatic products at trace concentrations. The method employed QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) and gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) as the sample preparation and measurement, respectively. The effect of the aqueous phase volume used in the QuEChERS was demonstrated, and the ratio of 10:10 (mL) between water and acetonitrile phase was used for 5 g of sample. Besides, dSPE using C18 and primary-secondary amine (PSA) was applied to remove the potential interferences from the food matrices, indicating no remarkable analyte loss. The linear range was built up from 0.50 ㎍ L^-1 to 3.0 ㎍ L^-1 (R² = 0.9993). Other criteria, i.e., repeatability (RSD_r = 0.86-1.96 %), reproducibility (RSD_R = 1.09-2.01 %), and recovery (over 90 %), were in accordance with Appendix F of AOAC (2016) for method performance. Although no trifluralin was detected for the commercial samples (fish, shrimp, and breaded shrimp), the spiked samples performed favorable recoveries and precision.

• Structural Engineering and Mechanics
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• 제77권6호
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• pp.705-720
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• 2021

Reinforced concrete (RC) columns are the primary type of vertical support used in building structures that sustain vertical loads. However, their strength may be insufficient due to fire, earthquake or volatile environments. The load demand may be increased due to new functional usages of the structure. The deformability of concrete columns can be greatly reduced under high axial load conditions. In response, a novel steel encasement that distinguishes from the traditional steel jacketing that is assembled by welding or bolt is developed. This novel strengthening method features easy installation and quick strengthening because direct fastening is used to connect the four steel plates surrounding the column. This new connection method is usually used to quickly and stably connect two steel components by driving high strength fastener into the steel components. The connections together with the steel plates behave like transverse reinforcement, which can provide passive confinement to the concrete. The confined column along with the steel plates resist the axial load. By this way, the axial load capacity and deformability of the column can be enhanced. Eight columns are tested to examine the reliability and effectiveness of the proposed method. The effects of the vertical spacing between adjacent connections, thickness of the steel plate and number of fasteners in each connection are studied to identify the critical parameters which affect the load bearing performance and deformation behavior. Lastly, a theoretical model is proposed for predicting the axial load capacity of the strengthened RC columns.

• 한국세라믹학회지
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• 제49권6호
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• pp.542-548
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• 2012

The viscosity of a ceramic slurry depends on the slurry concentration, particle shape and size, hydrodynamic interactions, temperature, shear rate, pre-treatment condition and the method of measurement with the selected equipment. Representative ceramic slurries with low to high viscosity levels are selected from colloidal silica, barium titanate slurry and glass frit paste. Rotational rheometers and vibrational viscometers are used to compare the measured viscosity for various ceramic slurries. The rotational rheometer measured the viscosity according to the change of the shear rate or the rotational speed. On the other hand, the vibrational viscometer measured one point of the viscosity in a fixed vibrational mode. The rotational rheometer allows the measurement of the viscosity of a ceramic paste with a viscosity higher than 100,000 cP, while the vibrational viscometer provides an easy and quick method to measure the viscosity without deformation of the ceramic slurry due to the measurement method. It is necessary to select suitable equipment with which to measure the viscosity depending on the purpose of the measurement.

• Clinical and Experimental Pediatrics
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• 제48권12호
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• pp.1348-1353
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• 2005

목 적 : 인플루엔자는 해마다 유행하는 호흡기 질환으로서 만성질환자나 노인 뿐만 아니라 영아나 소아에게도 높은 유병률과 치사율을 나타내어 임상적 중요성이 주목되고 있다. 임상증상만으로는 다른 호흡기 바이러스나 세균감염과 감별이 어렵고, 전통적인 진단방법인 바이러스 배양검사는 소요 시간이 길고 배양방법도 까다로워 진단이 늦어지고 치료에도 적용하지 못하였다. 이에 따라 최근 검사방법이 간편하고 결과를 빨리 알 수 있는 신속검사법들이 소개되어 그 정확성과 임상에의 유용성이 많이 연구되고 있으나 국내에서는 연구례가 드문 실정이다. 이에 저자들은 신속검사의 정확성과 유용성을 평가하여 실질적인 검사법으로 정착시키고자 하였다. 방 법 : 2004년 1월부터 6월, 2005년 2월부터 6월까지 발열, 기침, 인후통 및 근육통 등의 증상으로 외래 내원 및 입원 치료를 받은 408명의 환아를 대상으로, 비인두 가검물을 채취하여 QuickVueR(Quidel Co., San Diego, USA) influenza rapid antigen test와 바이러스 배양을 동시에 시행하였다. 결 과 : 평균 연령은 $2.51{\pm}2.65$(2개월-15세)이고 남아는 239명, 여아는 169명이었다. 바이러스 배양에 양성을 보인 환아는 77명으로 이중 A/H3N2형은 55명(71.4%), B형은 22명(28.5%)이었다. 본 검사의 민감도는 71.4%, 특이도는 95.8%, 양성예측도는 79.7%, 음성예측도는 93.5%였으며 위양성률과 위음성률이 각각 4.2%, 28.5%로 나왔다. 결 론 : 본 검사는 비교적 민감도가 높아 선별 검사로서 적합하다고 생각되며, 특히 특이도가 높고 위양성률이 낮아 결과가 양성으로 나왔을 시 인플루엔자 감염의 가능성이 높아, 치료를 빨리 시작함으로써 증상의 호전을 기대할 수 있겠다. 앞으로 이러한 신속검사가 실제 임상에 널리 적용된다면 환자 침상에서 간편하고 빠르게 검사하여 결과를 바로 알고 치료를 조속히 시작하여 합병증을 줄이고 불필요한 항생제의 사용을 줄일 수 있으리라 기대된다.

• Journal of Korean Neurosurgical Society
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• 제40권3호
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• pp.206-209
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• 2006

Objective : Traditionally, standard access to the posterior fossa was a suboccipital craniectomy. After introducing the technique and benefit of posterior fossa craniotomy, several surgeons have used this procedure to manage various pathologies in posterior fossa in children. Though this approach offers several advantages over conventional suboccipital craniectomy, the elevation of bone flap is not easy in adult because of the irregular contour of inner bone surface and tight adhesion of dura to the skull. The aim of this article is to describe the technical aspects of this approach and to delineate the important landmarks for a safe and quick performance in adult. Methods : We report on our series of twenty-five adult patients who underwent craniotomy for posterior fossa pathologies between 2002 and 2005. The maximal follow-up period was 4 years. Results : None of the patients complained of persistent headache and no CSF leaks have occurred postoperatively. We have encountered only two cases of transient subcutaneous CSF retention after craniotomy. Three-dimensional reconstruction of the CT scan confirmed the well-fitted suboccipital bone contour after craniotomy. And patients were satisfied with the cosmetic results. Conclusion : This method is safer and simpler. It restores normal anatomical planes and improves protection of the contents of the posterior fossa. The authors recommend craniotomy as an alternative method of access to the posterior fossa in all age groups.

• 한국주조공학회지
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• 제34권1호
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• pp.14-21
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• 2014

Magnesium and its alloys are being applied to various kinds of industrial fields, especially their use on automotive parts and electronic part. These parts are manufactured mainly through diecasting process and magnesium ingots are used as raw materials. In the case that ingot quality is not secured, massive casting defects can occur and some manufactures can be damaged by the defects. This study is to evaluate ingots' cleanliness of magnesium alloys. It includes composition analysis by spectrometer, measurement of inclusion contents by SEM, brightness test on fractured surface and etc. Especially, the brightness test is a very easy and quick evaluation method. The brightness becomes low when the amount of oxides or inclusions on the surface increases. The brightness test data have been compared with those obtained from other methods for measuring the mount of impurities, which showed good relationship between the brightness and the others. Thus, the brightness test could be a promising method to measure the cleanliness of magnesium alloys.

• The Journal of Korean Physical Therapy
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• 제11권1호
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• pp.149-156
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• 1999

Resistive therapeutic exercise prescription goal is to improve functional performance and capabilities through the development of increased muscular strengh endurance or power. Resistance can be applied to either dynamic or static muscle contractions. Resistive therapeutic exorcise can be carried nut concentrically, eccentrically, isometrically, isokinetically. Neurodevelopmental treatment has not resistive therapeutic exercise concept. But proprioceptive neuromuscular facilitate techniques have resistive therapeutic exercise concept with pattens and techniques. It is aid muscle contraction, motor control and increase strength. Manual muscle testing will help the therapist establish a qualitative and quantitative baseline level of strength. Manual resistance maybe applied a against controlled lengthening contraction re static contraction of a muscle. A repetition maximum is not easy to calculate and is not the most accurate method available today to measure strength before of after a resistive therapeutic exercise program. Oddvar Holten Diagram is essy to calculate and is the most accurate method available today to measure strength before of after a resistive therapeutic exercise program. Plyometric training emphasize the development of muscular power and coordination. Quick bursts of force in functional movement patterns are often necessary of a patient is to return to high-demand occupational, recreational or sports related activities.