• Journal of Trauma and Injury
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• 제26권4호
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• pp.261-265
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• 2013

Purpose: The aim of this study is to evaluate the transfer pattern of multiple trauma patients after acute phase management and to determine whether the time between the surgeon's decision and the actual transfer correlates with the patient's insurance type. Methods: Three hundred ninety-two(392) multiple trauma patients visited the emergency room from January 2011 to April 2013. Among the 143 patients who were admitted by a trauma surgeon, 47 were transferred to another hospital after acute phase management. The age, gender, trauma mechanism, Revised trauma score (RTS), Injury severity score (ISS), insurance type, length of ICU stay and hospital stay were analyzed through a retrospective chart review. Results: The mean age was 47.7 years, and traffic accident was the most common mechanism(26, 55.3%). The mean RTS and ISS were 6.93 and 22.7, respectively. Twenty-five patients(53%) were covered by National health insurance, and 20 patients(42.6%) were covered by automobile insurance. Patients were transferred to primary (4.3%), secondary(80.9%), tertiary(4.3%) and care(10.6%) hospitals. The mean time from transfer decision to actual transfer was significantly longer for patients who were covered by automobile insurance than it was for patients who were covered by national health insurance (p=0.038). Conclusion: An appropriate transfer system at the end of acute phase care is essential for managing trauma centers with limited staffing and facilities. In addition, the mean time from transfer decision to actual transfer seemed to be definitely related to the type of insurance covering the patient.

• 약학회지
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• 제42권5호
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• pp.473-479
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• 1998

Lovastatin (LOVA), a fungal metabolite isolated from cultures of Aspergillus terreus, is a competitive HMG-CoA reductase inhibitor used for the treatment of primary hyper cholesterolemia, and has also been shown to suppress growth in a variety of non-glioma tumor cell lines. A sensitive reversed-phase high-perfonnance liquid chromatographic method with ultraviolet (UV) absorbance detection has been developed to quantitate LOVA in human plasma and urine samples using liquid-liquid extraction procedure. Baseline separation of LOVA and internal standard, simvastatin was achieved on a Novapak $C_{18}$ analytical column with a mobile phase containing 0.025M $NaH_2PO_4$: CAN (35:65, v/v%), adjusted pH to 4.5. The flow rate was set at 1.5ml/min, and the column effluent was monitored by a UV detection at 238nm. The limit of quantification was determined to be 0.5${\mu}$g/ml while extraction efficiency of LOVA ranged from 73.4-82.9% at LOVA concentrations of 0.5 to 10${\mu}$g/ml. Good linearity with correlation coefficients greater than 0.999 was obtained in the range of LOVA concentrations from 0.5 to 10${\mu}$g/ml. The accuracy and the precision were proven excellent with relative standard deviation (RSD, %) and relative error (RE, %) of less than 4.2 and 4.0, respectively. Intraday precision, evaluated at five LOVA concentrations (0.5, 1, 2, 5, 10${\mu}$g/ml) and expressed as RSD ranged from 0-1.82% while the interday precision at the same concentrations ranged from 0.7-10.5%. The analytical method described was then successfully employed for the determination of LOVA concentrations in plasma samples obtained during a phase II clinical trial using high doses of LOVA (30-40mg/kg/day). This method could be further utilized for the ongoing pharmacolkinetic studies and therapeutic drug monitoring of the high-dose LOVA therapy in adenocarcinoma patients.

• 대한간호학회지
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• 제50권4호
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• pp.583-598
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• 2020

Purpose: This study was to investigate the operational status of the midwifery birthing centers (MBCs) and midwives' job status (Phase 1) and to develop midwifery practice guidelines (MPG) (Phase 2) in Korea. Methods: In the first phase, the subjects were 15 midwives who operated 11 of 14 MBCs that were opened as of August 2018. The questionnaire consisted of items to measure the operational status of the MBC and midwives' job status. In the second phase, the MPG was developed from literature review, interviews with five midwives opening their MBCs, surveys with 74 midwives, and a validity evaluation conducted by seven experts. Results: The distribution of operating MBCs was five in Gyunggi-do, two each in Seoul and Incheon, one each in Busan, Chungcheongbuk-do, Gyeongsangbuk-do, Gyeongsangnam-do and Jeju-do. The mean age of midwives was 54.3 and all were female. In 2017, a total of 762 births including 81 homebirths were performed by midwives. The job performance was highest in the order of neonatal care 3.81, childbirth care 3.56, and postpartal care 3.53, respectively. The MPG included seven areas of prenatal care, childbirth care, postpartal care, neonatal care, primary health care, law/ethics, and administration, with 56 tasks and 166 task elements. Conclusion: This study provides the valid basic data for the operational status of the MBC and the midwives' job status. The MPG describes the midwife's job and may be used as basic data for preparing policies for the development of midwifery practice in Korea.

• Journal of Semiconductor Engineering
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• 제1권1호
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• pp.1-12
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• 2020

Handling precise timing in high-speed transceivers has always been a primary design target to achieve better performance. Many different approaches have been tried, and one of those is utilizing the beneficial nature of injection locking. Though the phenomenon was not intended for building integrated circuits at first, its coupling effect between neighboring oscillators has been utilized deliberately. Consequently, the dynamics of the injection-locked oscillator (ILO) have been explored, starting from R. Adler. As many aspects of the ILO were revealed, further studies followed to utilize the technique in practice, suggesting alternatives to the conventional frequency syntheses, which tend to be complicated and expensive. In this review, the historical analysis techniques from R. Adler are studied for better comprehension with proper notation of the variables, resulting in numerical results. In addition, how the timing jitter or phase noise in the ILO is attenuated from noise sources is presented in contrast to the clock generators based on the phase-locked loop (PLL). Although the ILO is very promising with higher cost effectiveness and better noise immunity than other schemes, unless correctly controlled or tuned, the promises above might not be realized. In order to present the favorable conditions, several strategies have been explored in diverse applications like frequency multiplication, data recovery, frequency division, clock distribution, etc. This paper reviews those research results for clock multiplication and data recovery in detail with their advantages and disadvantages they are referring to. Through this review, the readers will hopefully grasp the overall insight of the ILO, as well as its practical issues, in order to incorporate it on silicon successfully.

• Journal of Welding and Joining
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• 제23권6호
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• pp.93-98
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• 2005

The purpose of this study is to investigate the characteristics of pb-free $Zn-(3\~6)\%Al-(1\~6)\%Cu$ solder alloys for ultra high temperature(>573K) which applied to air craft, space satellite, automotive, oil, gas well exploration and data logging of geo-thermal wells. Melting range, solderability, electric resistivity, microstructure and mechanical properties were examined with solder alloys casted in Ar gas atmosphere. $Zn-4\%Al-(1\~3)\%Cu,\;Zn-5\%Al-(2\~4)\%Cu\;and\;Zn-6\%Al-(3\~5)\%Cu$ alloys satisfied the optimum melting range of 643 to 673k for ultra high temperature solder. A melting temperature increased with increasing Cu content, but decreased with increasing Al content. The spreadability was improved with increasing hi content. But the content of Cu had no effect on the spreadability. The electric resistivity was lowered with increasing Al and decreasing Cu content. In all Zn-Al-Cu solder alloys, primary dendritic $\varepsilon$ phase(Zn-Cu), dendritic $\eta$ phase(Zn-Cu-Al), $\alpha(Al-Zn)-\eta$ eutectic and eutectoid phase were observed. The addition of Al increased the volume fraction of eutectic and eutectoid phase and it decreased f phases. Also, the addition of Cu increased slightly the volume fraction of e, the eutectic and eutectoid phases. With increasing total content of Al and Cu, a hardness and a tensile strength were linearly increased, but anelongation was linearly decreased.

• 전기전자학회논문지
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• 제25권3호
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• pp.517-527
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• 2021

본 논문에서는 단일칩 마이컴을 이용한 위상변위 방식 직류-직류 전력변환기를 제안한다. 제안한 전력변환기의 1차측은 위상변위 방식에 의하여 단극성 펄스폭변조(unipolar PWM)로 동작하는 풀브리지 전력구조이며, 2차측은 4개의 다이오드로 구성된 풀브리지 전파정류기이다. 제안한 전력변환기의 제어는 단일칩 마이컴에 의해 수행되고, 그 MOSFET 스위치들은 부트스트랩 회로에 의해 구동된다. 그래서 전력변환기의 전체 시스템은 간단하다. 제안한 전력변환기는 공진회로와 저지커패시터를 이용하여 고효율을 달성한다. 본 논문에서는 먼저, 제안한 전력변환기의 전력회로의 동작을 각 동작모드를 따라 설명한다. 그리고 제안한 전력변환기의 전력회로 설계방식을 보이고 제안한 전력변환기를 동작시키는 마이컴 상의 소프트웨어 제어 알고리즘과 피드백 및 스위치 구동 회로에 관하여 간략히 설명한다. 그 후, 본 논문에서 제시한 설계와 구현방식에 의하여 설계하고 제작된 시제품 전력변환기의 실험결과를 통하여 제안한 전력변환기의 동작 특성을 입증한다. 실험결과에서 약 92% 정도의 최고 효율을 얻었다.

• 한국임상약학회지
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• 제29권2호
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• pp.71-78
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• 2019

Objective: This study aimed to provide efficacy and safety information on the use of erenumab for prevention of episodic and chronic migraines. Methods: The keywords "Erenumab and migraine" were used to search the PubMed database to then compile efficacy and safety data for erenumab. Data from relevant Phase 2 and Phase 3 clinical trials were analyzed, using RevMan for statistical analysis. Results: Three clinical trials (one Phase 2 and two Phase 3 studies) were retrieved. All three trials used the same primary endpoint (change from baseline in monthly migraine days (CBMD)) to evaluate efficacy and safety of erenumab use for prevention of episodic and chronic migraines. Subcutaneous doses of erenumab (70 or 140 mg) were administered monthly in each trial, for 3 months (Studies 2, and 3) or 6 months (Study 1). The mean differences in CBMD in the 70 mg and 140 mg erenumab arms were -1.36 and -1.98, respectively, compared to that in the placebo arm. Some adverse events, such as nasopharyngitis and upper respiratory tract infection, were reported, but no differences in safety between erenumab and placebo were found to be significant. Conclusions: Erenumab showed superior efficacy in prevention of migraines compared to placebo. However, additional information regarding the long-term safety of erenumab should be collected. Therefore, post-marketing surveillance for adverse events is needed.

• Journal of Gastric Cancer
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• 제20권4호
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• pp.395-407
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• 2020

Purpose: A phase II study was conducted to evaluate the safety and efficacy of preoperative, intra-arterial perfusion of epirubicin, etoposide, and oxaliplatin combined with oral chemotherapy S-1 (SEEOX) for the treatment of type 4 gastric cancer. Materials and Methods: A single-center, single-arm phase II trial was conducted on 36 patients with histologically proven type 4 gastric cancer without distant peritoneal or organ metastasis. Patients received 3, 21-day courses of SEEOX preoperative chemotherapy. The primary endpoint was overall survival (OS) and the secondary outcomes assessed were chemotherapeutic response, radical resection rate, pathological regression, toxicities, postoperative morbidity, and mortality. Results: All patients were at an advanced stage of cancer (stage III or IV) and completed the entire course of treatment. Based on changes in tumor volume and peritoneal metastasis, the objective response rate was 55.6% (20/36; 95% confidence interval [CI], 38.5%-72.6%) and the disease control rate was 69.4% (25/36; 95% CI, 53.6%-85.3%). The radical resection rate was 75% (27/36; 95% CI, 60.1%-89.9%) and the proportion of R0 resections was 66.7% (21/36; 95% CI, 50.5%-82.8%). The pathological response rate was 33.3%, of which 13.9% showed complete pathological regression. The median survival was 27.1 months (95% CI, 22.24-31.97 months), and the 2-year OS was 48.5% (95% CI, 30.86%-66.1%). Conclusions: Preoperative SEEOX is a safe and effective treatment for type 4 gastric cancer. Based on these preliminary data, a phase III study will be conducted to confirm the superiority of this regimen over standard treatment.

• 전기학회논문지
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• 제57권6호
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• pp.938-943
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• 2008

Coupling capacitor voltage transformers(CCVTs) have been used in extra or ultra high voltage systems to obtain the standard low voltage signal for protection and measurement. For fast suppression of the phenomenon of ferroresonance, three winding CCVTs are used instead of two winding CCVTs. A tuning reactor is connected between a capacitor voltage divider and a voltage transformer to reduce the phase angle difference between the primary and secondary voltages in the steady state. Slight distortion of the secondary voltage is generated when no fault occurs. However, when a fault occurs, the secondary voltage of the CCVT has significant errors due to the transient components such as dc offset component and/or high frequency components resulting from the fault. This paper proposes an algorithm for compensating the secondary voltage of a three winding CCVT in the time domain. With the values of the measured secondary voltage of the three winding CCVT, the secondary, tertiary and primary currents and voltages are estimated; then the voltages across the capacitor and the tuning reactor are calculated and then added to the measured voltage. Test results indicate that the algorithm can successfully compensate the distorted secondary voltage of the three winding CCVT irrespective of the fault distance, the fault impedance and the fault inception angle as well as in the steady state.

• 전력전자학회논문지
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• 제13권5호
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• pp.396-402
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• 2008

본 논문에서는 영전압 스위칭 풀브릿지 컨버터에 적용할 수 있는 새로운 방식의 복합 변압기(Integrated magnetics) 구조를 제안하고 시험용 컨버터에 적용하여 실험 결과를 보고한 것이다. 제안된 복합변압기의 권선 방법은 두 개의 1차측 권선을 병렬로 하고 2차측 권선은 중앙에 탭이 있는 배전압 방식으로 구성이 된다. 복합변압기의 구조는 기본적으로 EE, EI 코어를 이용하며 코어 양쪽 다리에 변압기의 1, 2차 권선이 각각 위치하고, 중앙의 다리에는 출력 필터용 인덕터 권선을 구성한다 제안된 복합변압기의 성능을 평가하기 위해서 100kHz의 스위칭 주파수, 12V 출력전압과 최대출력 720W급의 컨버터를 제작하였으며 복합변압기는 전 범위에서 동작이 안정되었으며 컨버터는 최대 92%의 전력변환효율을 나타내었다.