Bloodstream Infections and Clinical Significance of Healthcare-associated Bacteremia: A Multicenter Surveillance Study in Korean Hospitals

Son, Jun Seong,Song, Jae-Hoon,Ko, Kwan Soo,Yeom, Joon Sup,Ki, Hyun Kyun,Kim, Shin-Woo,Chang, Hyun-Ha,Ryu, Seong Yeol,Kim, Yeon-Sook,Jung, Sook-In,Shin, Sang Yop,Oh, Hee Bok,Lee, Yeong Seon,Chung, Doo The Korean Academy of Medical Sciences 2010 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.25 No.7

<P>Recent changes in healthcare systems have changed the epidemiologic paradigms in many infectious fields including bloodstream infection (BSI). We compared clinical characteristics of community-acquired (CA), hospital-acquired (HA), and healthcare-associated (HCA) BSI. We performed a prospective nationwide multicenter surveillance study from 9 university hospitals in Korea. Total 1,605 blood isolates were collected from 2006 to 2007, and 1,144 isolates were considered true pathogens. HA-BSI accounted for 48.8%, CA-BSI for 33.2%, and HCA-BSI for 18.0%. HA-BSI and HCA-BSI were more likely to have severe comorbidities. <I>Escherichia coli</I> was the most common isolate in CA-BSI (47.1%) and HCA-BSI (27.2%). In contrast, <I>Staphylococcus aureus</I> (15.2%), coagulase-negative <I>Staphylococcus</I> (15.1%) were the common isolates in HA-BSI. The rate of appropriate empiric antimicrobial therapy was the highest in CA-BSI (89.0%) followed by HCA-BSI (76.4%), and HA-BSI (75.0%). The 30-day mortality rate was the highest in HA-BSI (23.0%) followed by HCA-BSI (18.4%), and CA-BSI (10.2%). High Pitt score and inappropriate empirical antibiotic therapy were the independent risk factors for mortality by multivariate analysis. In conclusion, the present data suggest that clinical features, outcome, and microbiologic features of causative pathogens vary by origin of BSI. Especially, HCA-BSI shows unique clinical characteristics, which should be considered a distinct category for more appropriate antibiotic treatment.</P>

폐렴구균의 용혈능 변화와 pneumolysin 유전자의 변이 양상

오원섭,장현하,정숙인,김연숙,이혁,김신우,김성민,백경란,이남용,송재훈 대한화학요법학회 2002 대한화학요법학회지 Vol.20 No.3

목적 : 폐렴구균은 인체에서 폐렴, 수막염 및 패혈증 등을 일으키는 중요한 병원균으로 현재 전 세계적으로 항균제 내성이 큰 문제가 되고 있다. 하지만 폐렴구균의 항균제 내성에 따라 병독성이 어떻게 변화하는지에 대해서는 구체적으로 알려져 있지 않다. 이에 기능적 및 구조적 분석을 통하여 폐렴구균의 주요 병독성 인자인 pneumolysin의 병인론적 역할을 규명하고자 하였다. 방법 : 임상 검체에서 분리된 페니실링 감수성 균주 20주와 내성 균주 20주를 대상으로 하였다. Pneumolysin의 세포 독성의 변화를 관찰하기 위하여 각각의 균주들의 용혈능을 측정하였고, pneumolysin 유전자를 중합효소 연쇄반응으로 증폭한 후 증폭 산물의 유전자 구조를 분석하였다. 결과 : 페니실린 감수성 균주와 내성 균주간의 용혈능은 유의한 차이를 보이지 않았으나, 일부 용혈능이 매우 낮은 균주에서 Lys152→Thr, Thr-172→Ile, Lys-224→Arg와 같은 변이가 관찰되었다. 결론: pneumolysin의 세포 독성의 변화는 항균제 내성 정도와는 무관하였으나, 일부 용혈능이 저하된 균주에서 발견된 pneumolysin 유전자의 변이가 pneumolysin의 세포 독성에 영향을 주는 것으로 보인다. Background : Pnumolysin (Ply) is one of the most important virulence factors of Streptococcus pneumoniae. To investigate the functional and structural variation of Ply, hemolytic activity (HA) and gene sequences of pneumolvsin were determined. Methods : A total of 40 invasive pneumococcal isolated (20 penicillin-susceptible & 20-resistant strains) were analyzed. HA of each isolate was measured in crude extracts (1×10^8 CFU/mL) hourly from the time of inoculation to 9h. Crude extracts (50㎕) and DTT buffer (100㎕) were serially diluted in 96-well plate and mixed with 1% sheep blood (50㎕). HA was represented as the reciprocal of the greatest dilution, which resulted in the complete lysis. Two sets of oligonucleotide primers were used to amplify a 1,474-bp fragment containing the coding region and a 578-bp fragment of upstream region of ply gene, respectively. Amplified products were directly sequenced. Results : HA showed a wide variation from 0 to 87,480 regardiess of penicillin MICs, serotypes or specimen sources. Two bacteremic strains showed completely no hemolytic activity. No significant differences in HA between penicillin-susceptible (Mean± SE : 15,468± 4,693) and penicillin-resistant strains (21,384± 4,087) were found (p > 0.05).Sequencing of the coding region showed unique alterations in amino acids in strains with markedly reduced hemolytic activity (≤ 40): Thr-172-Ile and Lys-224-Arg. However, upstream region of ply gene was highly conserved. Conclusions : Ply activity was not related with antibiotic resistance. Absence of HA in some strains was associated with unique alterations in amino acid sequences in ply gene. Relationnship between genomic alteration and functional changes in pneumolysin should be further investigated.

아시아 지역 폐렴 구균의 항균제 내성 현황 및 변화 양상 : Asian Network for Surveillance of Resistant Pathogens (ANSORP) Study

정숙인,김나영,손준성,기현균,고관수,서지연,장현하,김연숙,오원섭,백경란,이남용,송재훈,항생제 내성 감시를 위한 아시아 연합 (ANSORP) 대한감염학회 2004 감염과 화학요법 Vol.36 No.1

목적 : 1980년대부터 페니실린을 비롯한 β-lactam 계열과 비 β-lactam 계열 항균제에 대한 폐렴구균의 항생제 내성이 급격하게 증가하여 국내 뿐 아니라 세계적인 문제로 대두되고 있다. ANSORP 에서는 아시아 지역에서 폐렴구균의 항균제 내성과 그 변화 추이, 내성의 기전 및 위험인자를 분석하고자 본 국제 공동 연구를 시행하였다. 재료 및 방법 : 1999년 11월부터 2001년 8월까지 아시아 지역 12개국의 14개 기관에서 폐렴구균 감염증 환자의 임상 검체로 분리된 침습성 폐렴구균을 대상으로 액체배지 미량희석법을 이용하여 16개 항생제의 MIC를 구하였다. 위험인자의 분석을 위하여 폐렴구균 감염증 환자를 대상으로 의무기록지를 조사하였다. Quellung 반응을 통해 혈청형을 결정하였다. 결과 : 총 685균주 중 52.4%가 페니실린에 대하여 비감수성(중등도 내성 22.9%, 내성 29.5%)을 보였고, 그 빈도는 베트남(92.1%), 스리랑카(85.7%), 홍콩(67.9%), 한국(64.5%)의 순이었다. Erythromycin에 대한 비감수성 비율은 베트남(92.1%), 대만(87.7%), 한국(80.6%), 홍콩(76.8%) 등에서 높게 나타났고, 베트남, 대만, 한국, 홍콩 등의 erythromycin의 MIC_(90)이 32㎍/mL를 넘는 고도내성을 보였다. 홍콩, 싱가포르, 대만, 인도에서는 fluoroquinolone에 대한 내성 균주가 출현하였다. 전체 균주 중 다제내성 균주의 비율은 47.7%였다. 혈청형은 19형과 23형이 가장 많았고, 그 외 6형, 14형 등이 있었다. 페니실린 비감수성 감염증의 위험인자로는 5세 미만(OR=1.7; 95%, CI, 1.2-2.4; P=0.002), 기관지폐질환(OR=2.0; 95%, CI, 1.3-3.1; P=0.003), 악성종양(OR=2.3; 95%, CI, 1.2-4.6; P=0.015), 스테로이드의 사용(OR=2.8; 95%, CI, 1.1-7.4; P=0.032)이 확인되었다. 결론 : 침습성 폐렴구균 균주를 대상으로 한 본 연구의 결과 아시아 국가들에서 페니실린, β-lactam 및 macrolide에 대한 폐렴구균의 내성률 및 내성 정도가 급증하고 있음을 확인하였다. Background : Emergence of pneumococcal resistance became a global issue since 1990s. According to the ANSORP studies with clinical isolates and carriage isolates between 1996 and 1999, some Asian countries showed alarmingly high prevalence of resistance to penicillin and other antimicrobial agents. To investigate the changing trends of pneumococcal resistance, ANSORP study group has performed a multinational surveillance study with invasive pneumococcal isolates from Asian countries. Methods : All isolates from various invasive pneumococcal diseases were prospectively collected from 14 centers in 12 countries between November 1999 to August 2001. Broth microdilution tests with 16 antimicrobial agents were performed according to the NCCLS procedures. Serotyping was performed by means of Quelling reaction with use of group-specific antisera. Results : A total of 685 isolates were collected. Overall, 52.4% of invasive isolates from Asian countries were not susceptible to penicillin (intermediate (1), 22.9%, Resistant (R), 29.5%). Vietnam showed the highest prevalence of penicillin non-susceptibility (1 20.6%, R 71.4%) followed by Sri Lanka (1 71.4%, R 14.3%), Hong Kong (1 24.1%, R 76%) and Korea (1 9.7%, R 54.8%). China (I 19.8%, R 23.4%) and Malaysia (1 9.1%, R 29.5%) also showed remarkable increase in penicillin resistance compared with previous ANSORP data, which were less than 10%. Vietnam (92.1%), Taiwan (87.7%), Korea (80.6%), and Hong Kong (76.8%) showed high prevalence of erythromycin resistance. MIG_(90)S for ciprofloxacin were 4 ㎍/mL (Hong Kong) and 2 ㎍/mL (11 Asian countries except Hong Kong), respectively. Conclusion : Compared with previous data from ANSORP studies, antimicrobial resistance among invasive pneumococcal isolates has markedly increased in Vietnam, Sri Lanka, Taiwan, China, and Malaysia. Continuous surveillance of pneumococcal resistance in Asia is strongly warranted.

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

Real-Time External Compensation of Threshold Voltage Shift Using Double-Gate Oxide TFTs in a Gate Driving System

You, Bong-Hyun,Lee, Soo-Yeon,Hong, Seok-Ha,Lee, Jae-Hoon,Kim, Hyun-Chang,Ju, Ha-Ram,Choi, Moon-Chul,Jeong, Deog-Kyoon IEEE 2016 Journal of display technology Vol.12 No.9

<P>In order to suppress the malfunction caused by the shift of the threshold voltage (V-TH) of oxide thin film transistors (TFTs) to a negative value, double-gate TFTs are used in the shift register of the gate driving system to control V-TH by adjusting the top gate bias. The proposed circuit detects the current consumption of the shift register and adjusts V-TH so that the current consumption of the shift register is regulated within the desired value. The system includes a compensation algorithm, which can search for an optimized top gate bias in various circumstances such as process fluctuations and ambient temperature change. The proposed system provides a stable operation compared with a conventional structure especially at high temperature. Experimental results show that, in the conventional system without compensation, the output voltage of the shift register deteriorates at 80 degrees C and above, and the power consumption increases from 1.15 to 2.14 mW after 21600 s of continuous operation at 60 degrees C. On the other hand, the proposed system provides a stable gate output up to 100 degrees C and keeps the power consumption below 1.10 mW by adjusting the top gate bias responding to environment changes.</P>

Design of a shape memory composite(SMC) using 4D printing technology

Kang, Minkyu,Pyo, Youngjun,Jang, Joon young,Park, Yunchan,Son, Yeon-Ho,Choi, MyungChan,Ha, Joo wan,Chang, Young-Wook,Lee, Caroline Sunyong Elsevier 2018 Sensors and actuators. A Physical Vol.283 No.-

<P><B>Abstract</B></P> <P>A fused deposition modeling (FDM) tool was used to fabricate a shape memory composite (SMC) that combined a shape memory alloy (SMA) with a shape memory polymer (SMP). The SMA caused a shape memory effect due to a phase change between martensite and austenite phases, in turn due to a temperature change. Also, the SMP had a shape memory effect caused by changes in the proportions of hard and soft segments near the glass transition temperature (T<SUB>g</SUB>). Usually, common SMAs and SMPs are not reversible, so these materials do not go back to their original shapes once they are deformed. In this study, we fabricated 4D printing actuator via reversible SMC actuations using 3D printing technology. Nylon 12 was used as the 3D printing material in filament form. Moreover, the volume fraction of SMA to SMP was varied to find the optimum ratio for good operation cycles. A volume fraction of SMA:SMP of 1:5 showed the largest length change, of 8 mm, and the most rapid response time, of 4 s in overall dimension of 140mm×10mm×1mm (length×width×thickness).Thus, the SMC showed promising results for the application of stents and valve controllers that could be manufactured by 3D printing technology.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An 4D printed SMC actuator was fabricated using SMA and SMP with a FDM 3D printer. </LI> <LI> A volume fraction of SMA:SMP of 1:5 showed the largest length change of 8 mm, and the most rapid response time of 4 s. </LI> <LI> The reversible actuator mechanism explains the SMC actuation via each shape memory effect. </LI> <LI> SMC showed potential application for stents and valve controllers via 3D printing technology to achieve customized designs. </LI> </UL> </P>

연속회분식 반응기를 이용한 축산 폐수의 생물학적 고도 처리 운전 인자 도출에 관한 연구

김창원,최명원,이해군,이해일,하지연 부산대학교 환경문제연구소 1998 環境硏究報 Vol.16 No.-

축산폐수는 고농도의 유기탄소 뿐만아니라 영양염류를 포함하는 대표적인 고농도 폐수이며 적절히 처리되어지지 못할 경우 심각한 담수의 부영양화와 연안의 적조를 야기할 수 있다. 이러한 축산폐수를 보다 경제적이며 기술적으로 처리하기 위해 본 연구에서는 연속회분식반응기(SBR)을 이용한 축산폐수의 고도처리에 적용할 수 있는 운전인자와 운전기법을 연구하였다. 초기 암모니아와 유기탄소부하를 달리하며 정해진 주기로 운전하는 네 가지 전형적인 회분식 실험과 원수를 연속으로 주입하면서 간헐 폭기로 운전하는 세 가지의 변형회분식 반응 실험을 통하여 전형적인 SBR에서 비 질산화 속도에 가장 많은 영향을 미치는 인자가 초기 pH 와 유리 암모니움 농도이며 최적 초기 암포니아성 비 질소 부하율은 0.1 ~ 0.15 kg NH_4^+-N /kg VSS 근처이며 이때 비 질산화율은 0.06 kgNH_4-N/ kg MLVSS·day로 관찰되었으며, 변형 SBR로 운전하는 경우 최소 35%에서 최대 65% 까지 탈질용 외부기질 주입량을 절감할 수 있었다. Piggery wastewater is a representative of high strength wastewater which contents not only high concentration organic carbon but also nutrients. From this reason piggery wastewater could be cause a serious eutrophication of fresh water and red tide in coastal areas if not properly treated. In this study to treat these piggery wastewater technically and more economically, the operation parameters and methods for advanced treatment using Sequencing Batch Reactor (SBR) were investigated. Four sets of experiments were conducted on laboratory scale typical SBR (Fill in a time) with fixed cycle and different till ratio to evaluate most proper initial loading of organic carbon and nitrogen and three sets of experiments on laboratory scale inodified SBR (Fill continuously) with intermittent aeration. As results the nitrification rate was most sensitively affected by intial pH and free ammonia concentration and in typical SBR operation most profit initial specific nitrogen loading were investigate around 0.1~0.15kg NH_4^+-N /kg VSS and in this range the average specific nitrification rate was 0.06 kg NH_4-N/ kg MLVSS·day. And in modified SBR operation with most profit specific nitrogen loading rate the cost of external denitrification cost were saved minimum 35% to maximum 65% each experimental sets.

국내에서 발생하고 있는 사람 브루셀라증의 임상적 특성

김연숙,최영실,오원섭,권기태,이혁,이선희,손준성,김신우,장현하,정숙인,고관수,박미연,백경란,송재훈 대한감염학회 2006 감염과 화학요법 Vol.38 No.6

배경 : 2002년 내국인에서의 첫 사람 브루셀라증의 증례 보고 이후 국내에서 사람 브루셀라증이 빠른 증가를 보이고 있다. 이에 연구자들은 국내에서 발생하는 브루셀라증의 임상적 특성을 연구하고자 하였다. 방법 : 2003년부터 2006년 7월까지 7개 대학병원에 내원한 환자들을 대상으로 WHO의 진단기준에 의하여 확진된 브루셀라증 환자들의 의무기록을 후향적으로 조사분석 하였다. 배양된 균은 삼성서울병원에 의뢰하여 16S rRNA 유전자 분석방법을 이용하여 종을 확인하였고, 표준시험관응집검사는 국립보건원에 의뢰하여 시행하였다. 결과 : 34예의 환자들이 브루셀라증으로 확진되었고, 31명이 남자였다. 혈액에서 B. abortus가 증명된 경우가 8예, 표준시험관 응집검사상 의미 있는 항체가 상승을 보인경우가 26예이었다. 환자들은 대부분 축산업관련 종사자였고, 추후 브루셀라증으로 확진된 소와의 직접 접촉을 통해 감염된 것으로 여겨진다. 국내 사람 브루셀라증의 가장 흔한 증상은 발열이었고, 위장관계 합병증이 가장 흔히 동반되었다. 치료로는 doxycycline/rifampicin이 24예의 환자에서 doxycycline/aminoglycoside (streptomycin 혹은 gentamicin)이 10예의 환자에서 6주 이상의 기간 동안 투여되었다. 치료에 반응을 보이지 않는 환자는 없었고, 재발이 1예 있었다. 결론 : 국내에서 발생하는 사람 브루셀라증의 원인균으로 현재까지 분리 동정된 것은 B. abortus이며, 소 브루셀라증의 증가로 인해 인체감염사례가 함께 증가하는 것으로 사료된다. 위험 직업군 종사자들에서 감염된 소와의 직접 접촉을 통해 주로 발생하고 있는 브루셀라증의 임상종상은 국외에서 발생하는 경우와 유사한 양상을 보이고 있으며 치료에 대한 반응은 비교적 좋은 편이긴 하나, 추후 보다 많은 환자들을 대상으로 한 연구가 필요하리라 사료된다. 사람 브루셀라증의 조절을 위해서는 소 브루셀라증의 조절이 필수적이며, 브루셀라증의 조절에 성공한 선진국의 사례를 적극적으로 도입해야 할 것으로 생각된다. Background : Since the first Korean case of human brucellosis was reported in 2002, the incidence of human brucellosis has been rapidly increasing. We performed this study to evaluate the clinical characteristics of human brucellosis occurring in South Korea. Materials and Methods : Demographic features, clinical manifestations, and therapeutic outcomes of cases confirmed as brucellosis according to WHO diagnostic criteria were evaluated. Species of Brucella isolates were identified with 16S rRNA gene sequencing method. Serologic diagnosis was performed with standard tube agglutination test (STA). Results : A total of 34 cases were enrolled from 2003 to 2006 in six hospitals. Eight cases were confirmed with the isolation of Brucella from blood and 26 cases were confirmed with titer of antibodies ≥1:160 by STA. Male (31) was predominant and most of the patients were cattle farmers. The most common transmission route was direct contact with infected or their cattle byproducts. Fever was the most prominent symptom and fatigue followed. Gastrointestinal and musculoskeletal systems were commonly complicated. Patients were treated with doxycycline and rifampin or aminoglycosides for more than 6 weeks. All patients responded well to the therapeutic regimens, but one patient relapsed 10 months after treatment. Conclusion : Brucellosis occurring in Korea has been caused by B. abortus, whose preferred natural host animals are cattle. Korean patients were infected through direct contact with bovine brucellosis. Clinical manifestations of brucellosis were similar to those occurring worldwide. Therapeutic outcomes were good among patients with brucellosis in Korea. In order to prevent human brucellosis, measures to eradicate bovine brucellosis should precede.

인버터 구동 유도전동기의 가창소음 저감을 위한 새로운 펄스폭 변조기법

최규하,신우석,함연창 建國大學校 附設 産業技術硏究所 1992 논문집 Vol.17 No.-

The PWM inverter system are widely used to control the induction motor, and their switching frequency rises to the higher for better performances. But the upper should be limited for safe operation as well as switching loss reduction in the power transistor inverters. This makes the level of the audible noise much increased. In order to overcome such noise problem, a new PWM control technique is proposed in the power transistor inverters, of which carrier frequency is to change a according to the slope of the sine wave reference signal. As a result the frequency spectra are improved and hence the audible noise couble be reduced greatly.

Prevention of Adjacent Segmental Disease after Fusion in Degenerative Spinal Disorder: Correlation between Segmental Lumbar Lordosis Ratio and Pelvic Incidence–Lumbar Lordosis Mismatch for a Minimum 5-Year Follow-up

Whoan Jeang Kim,Chang Hyun Ma,Sang Ha Kim,Yeon Seung Min,Jae Won Lee,Shann Haw Chang,Kyung Hoon Park,Kun Young Park,Dae Gun Song,Won Sik Choy 대한척추외과학회 2019 Asian Spine Journal Vol.13 No.4

Study Design: Retrospective study. Purpose: Associations among risk factors related to adjacent segmental disease (ASD) remain unclear. We evaluated the risk factors and segmental lordosis ratio to prevent ASD developing after lumbar spinal fusion. Overview of Literature: Risk factors related to ASD development are age, sex, obesity, pre-existing degeneration, number of fusion segments, and decreased postoperative lumbar lordosis (LL). However, the associations among these factors are still unclear and should be clearly identified. Methods: We retrospectively reviewed data on 274 patients who underwent lumbar spinal fusion of three segments or below for lumbar degenerative disease from January 2010 to December 2012, with over 5 years of follow-up. Patients with preoperative sagittal vertical axis (SVA) >5 cm were excluded due to sagittal imbalance. A total of 37 patients with ASD and 40 control patients (CTRL) were randomly selected in a similar distribution of matching variables: age, sex, and preoperative degenerative changes. Sex, age, number of fusion segments, radiologic measurements, L4–5–S1/L1–S1 LL ratio, and spinopelvic parameters (pelvic incidence [PI], pelvic tilt [PT], sacral slope [SS], and SVA) were analyzed. Logistic regression was used to analyze the correlation between PI–LL mismatch and L4–5–S1 segmental lordosis rate. Results: No significant difference was found between ASDs and CTRL groups regarding age, sex, number of fusion segments, fusion method, and preoperative and postoperative spinopelvic parameters (PI, SS, PT, and LL). However, regarding the L4–5–S1/L1–S1 lordosis ratio, 50% (p=0.045), 60% (p=0.031), 70% (p=0.042), 80% (p=0.023), and 90% (p=0.023) were statistically significant; <20% (p=0.478), 30% (p=0.223), and 40% (p=0.089) were not statistically significant. In the postoperative PI–LL <10 group, ASD occurred less frequently than in the PI–LL >10 group, and the difference was statistically significant (p=0.048). Conclusions: Patients with a postoperative L4–5–S1/L1–S1 lordosis ratio >50% had less occurrence of ASD. Correcting LL according to PI and physiologic segmental lordosis ratio is important in preventing ASD.