Piezoelectric Materials: All‐Solution‐Processed Flexible Thin Film Piezoelectric Nanogenerator (Adv. Mater. 45/2012)

Chung, Sung Yun,Kim, Sunyoung,Lee, Ju‐,Hyuck,Kim, Kyongjun,Kim, Sang‐,Woo,Kang, Chong‐,Yun,Yoon, Seok‐,Jin,Kim, Youn Sang WILEY‐VCH Verlag 2012 ADVANCED MATERIALS Vol.24 No.45

<P>An all‐solution‐processed flexible piezoelectric nanogenerator, composed of polycrystalline ZnO thin film and functional polymer layers such as P3HT/PCBM and PEDOT:PSS, generates energy through a mechanical rolling and muscle stretching system. On page 6022, Youn Sang Kim, Sang‐Woo Kim, and co‐workers show that this all‐solution‐processed nanogenerator is feasible as a piezoelectric patchable device and is promising for use in future energy harvesters such as wearable human patches and mobile electronics. </P>

황색포도구균의 균혈증에서 초기 항생제 치료가 예후에 미치는 영향

김성한,박완범,이기덕,강철인,최영주,김홍빈,박상원,김의석,오명돈,김의종,최강원 대한감염학회 2002 감염 Vol.34 No.5

Electropulsing Treatment on Enhancement of Electrical Conductivity of Screen-Printed Ag Wire

Ju‑Won Park,Howook Choi,Hwangsun Kim,Simoon Sung,Hye‑Jin Jeong,Il Kim,Jaeseok Gong,Sung‑Tae Hong,Heung Nam Han 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5

The effect of high electric current density on the sintering of Ag wires manufactured by screen printing is evaluated throughelectrical resistivity analysis and microstructure observation. Different forms (continuous and pulsed) of electric currentwith different current densities are applied to the specimens. Conventional heat treatment is also performed as a controlgroup to examine the athermal effect of electropulsing treatment. Compared to the conventional heat treatment, the resistivityis reduced more under the electropulsing treatment with continuous current for the same temperature and treatment time.Also, the process time of electropulsing treatment can be reduced by applying a pulse form of high density current insteadof continuous current without losing the benefit of enhanced reduction of resistivity. The microstructural observationsobtained from high angle annular dark field scanning transmission electron microscope and a digital precession instrumentclearly show that necking connecting the crystals is formed more firmly under electric current. In addition, the temperaturechange of Ag wire and substrate is calculated according to the change of the resistivity when the electric current is appliedto confirm the reliability.

Effects of Phenytoin and Diazepam on the Seizure Activity in the Cortical Dysplasia Animal Models

Kim, Si-Hyung,Choi, In-Sun,Cho, Jin-Hwa,Park, Eun-Ju,Jang, Il-Sung,Choi, Byung-Ju,Kim, Hyun-Jung,Kim, Young-Jin,Nam, Soon-Hyeun The Korean Academy of Oral Biology 2006 International Journal of Oral Biology Vol.31 No.2

Dysplasia-associated seizure disorders are markedly resistant to pharmacological intervention. Relatively little research has been conducted studying the effects of antiepileptic drugs(AEDs) on seizure activity in a rat model of dysplasia. We have used rats exposed to methylazoxymethanol acetate(MAM) in utero, an animal model featuring nodular heterotopia, to investigate the effects of AEDs in the dysplastic brain. Pilocarpine was used to induce acute seizure in MAM-exposed and age-matched vehicle-injucted control animals. Field potential recordings were used to monitor amplitude and numbers population spikes, and paired pulse inhibition in response to stimulation of commissural pathway. Two commonly used AEDs were tested: diazepam 5, 2.5mg/kg;phenytoin 40, 60mg/kg. Diazepam(DZP) and phenytoin(PHT) reduced the amplitude of population spike in control and MAM-exposed rats. However, the amplitude of population spike was nearly eliminated in control rats as compared to the MAM-exposed rats. Pharmaco-resistance was tested by measuring seizure latencies in awake rats after pilocarpine administration(320mg/kg, i.p.) with and without pretreatment with AEDs. Pre-treatment with PHT 60 mg prolonged seizure latency in control rats, but not in MAM-exposed animals. The main findings of this study are that acute seizures initiated in MAM-exposed rats are relatively resistant to standard AEDs assessed in vivo. These data suggest that animal model with cortical dysplasia can be used to screen the effects of potential AEDs.

개질아스팔트 콘크리트의 변형강도와 소성변형특성 연구

김광우,최선주,이문섭,홍상기,안경애,이순제 강원대학교 부설 석재복합신소재 제품연구센터 2003 석재연 논문집 Vol.8 No.-

본 연구는 정하중하에서 최대하중과 변형을 이용하여 구한 변형강도(K_(D))로부터 아스팔트 콘크리트의 소성변형 계수의 추정 가능성을 보여준다. 이 논문은 새로운 강도특성치인 K_(D)를 개발하는 김테스트 연구의 일부로 최근 2, 3단계의 연구결과이다. 19mm 편마암과 화강암 2가지 골재와 3가지 폴리머로 제조한 7가지 바인더로 같은 입도에서 소성변형 저항성이 다른 14가지 혼합물을 만들었다. 3단계에선 슬래브 공시체(30cm x 30cm x 6cm)를 제조후 반으로 나누어 한쪽 공시체에선 두 개의 김테스트 공시체 코어를 뜨고 다른 한쪽으로는 60℃ 반복주행(WT)시험을 수행하였다. 한편 2단계에선 슬래브 공시체의 가운데에서 WT 시험을 수행하고 그 양옆에서 김테스트 공시체 코어를 채취하였다. 4가지 하중봉을 사용하여 60℃에서 김 테스트를 수행하였다. 침하깊이-반복회수 곡선으로부터 최종 침하 깊이와 동적안정도 두 가지 소성변형 계수를 각 혼합물별로 구했다. 각 하중봉과 골재 별로 K_(D)와 소성변형 계수간의 통계적 상관관계 분석을 수행한 결과 K_(D)와 소성변형 계수와의 결정계수가 매우 높게(R² > 0.9) 나타났다. 그러므로 K_(D)는 소성변형 계수를 추정하는데 있어 매우 적합한 특성치이며 4cm 직경에 1cm 반경으로 원형절삭한 하중봉이 R² 가장 높게 나타나는 하중봉임을 알 수 있었다. 따라서 김테스트는 향후 소성변형을 추정하기 위한 표준화된 특성치로 사용할 수 있도록 더 연구 개발을 할 수 있을 것으로 판단되었다. This study shows predictability of rut parameters of asphalt concrete based on the deformation strength (K_(D)) which is obtained from the maximum load, deformation and size variables of loading head under simple static loading. This paper is the result of latest studies, phases 2 and 3, which are parts of Kim Test study for developing a new strength property, K_(D), for asphalt concrete. Two aggregates, gneiss and granite, with maximum size of 19mm and seven binders using three polymers(LDPE, SBS, SBR) were used to produce 14 different natures of rut resistance mixtures using the same gradation. A slab(30m x 30cm x 6m) was cut into two pieces and 2 cores for Kim test were taken from a half piece and the other piece was used for wheel tracking (WT) test at 60℃ in phase 3. In phase 2, WT test had been carried out in the middle of a whole slab and cores were taken from both sides of the wheel path along the center line. Kim test was performed using four loading heads at 60℃. Two rut parameters, depth of rut and dynamic stability, from the rut depth-cycle curve from a WT test were obtained for each mixture. Statistical analysis were performed for each loading head and aggregate to find out correlation between K_(D) values and each rut parameter. The analysis result showed that K_(D) had very high coefficient of determination (R² > 0.9) on the average with rut parameters. It was found that K_(D) is a good property that has excellent predictability for rut parameter of asphalt concretes, and the 4cm diameter loading head with 1cm curvature radius gave the best result in R². Therefore, Kim test can be further developed as a standard property for use in rut performance estimation of asphalt concretes.

Associations of serotonergic genes with poststroke emotional incontinence

Kim, Jae‐,Min,Stewart, Robert,Kang, Hee‐,Ju,Bae, Kyung‐,Yeol,Kim, Sung‐,Wan,Shin, Il‐,Seon,Kim, Joon‐,Tae,Park, Man‐,Seok,Cho, Ki‐,Hyun,Yoon, Jin‐ John Wiley Sons, Ltd 2012 INTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY Vol.27 No.8

<P><B>Objectives</B></P><P>Poststroke emotional incontinence (PSEI) has been associated with serotonergic dysfunction. Polymorphisms of serotonin transporter (5‐HTT) and serotonin 2a receptor (5‐HTR2a) genes may regulate serotonergic signaling at brain synapses, and this study was to investigate associations with PSEI in an East Asian population.</P><P><B>Methods</B></P><P>In 276 stroke cases, PSEI was diagnosed by Kim's criteria. Covariates included age, gender, education, history of depression or stroke, current depression, and stroke severity and location. Genotypes were ascertained for 5‐HTT gene‐linked promoter region (5‐HTTLPR), serotonin transporter intron 2 variable number tandem repeat, 5‐HTR2a 1438A/G, and 5‐HTR2a 102 T/C. Associations with PSEI were estimated by using logistic regression models, and gene–gene interactions were investigated by using the generalized multifactor dimensionality reduction method.</P><P><B>Results</B></P><P>PSEI was present in 37 (13.4%) patients. The 5‐HTT gene‐linked promoter region <I>s</I>/<I>s</I> genotype was independently associated with PSEI. No associations with STin2 VNTR and 5‐HTR2a genes were found, and no significant gene–gene interactions were identified.</P><P><B>Conclusions</B></P><P>Stroke patients with 5‐HTTLPR <I>s</I> allele had higher susceptibility to PSEI, which underlines the potential role of serotonergic pathways in its etiology. Copyright © 2011 John Wiley & Sons, Ltd.</P>

병원획득 Klebsiella pneumoniae 균혈증 분석을 통해 본 Ciprofloxacin 내성과 Extended-Spectrum β-Lactamase생성 간의 연관성

김미영,추은주,곽이경,송문희,나성수,송태준,김성혜,전재범,최상호,정진용,김남중,김양수,우준희,류지소 대한감염학회 2004 감염과 화학요법 Vol.36 No.5

목적 : K. pneumoniae는 ciprofloxacin내성 증가가 전세계적으로 문제가 되고있는 extended-spectrum beta-lactamase (ESBL)를 생성하는 대표적인 세균으로 최근 외국에서 ciprofloxacin 내성과 ESBL 생성사이에 관련이 있다는 2-3편의 보고들이 있었다. 본 연구에서는 병원획득 K. pneumoniae 패혈증이 있었던 환자들을 대상으로 ciprofloxacin 내성과 관련된 인자를 알아보고자 하였다. 재료 및 방법 : 2001년 1월 부터 2002년 12월 사이에 2200병상의 3차 의료기관인 한 대학병원에서 입원 후 72시간 이후에 나간 혈액배양에서 K. pneumoniae가 배양된 입원환자를 대상으로 의무기록과 전산기록을 분석하여 환자의 성별, 나이, 병동, 기저질환, 이전의 항생제 사용력, 패혈증 발생당시까지의 재원기간, 이전 입원력, 원인균의ESBL 생성유무 등을 파악하였고 이들 변수가 ciprofloxacin 내성과 관련이 있는지를 분석하였다. 재발성 패혈증의 경우는 첫 번째 경우만을 분석에 포함하였다. 결과 : 연구대상 환자는 총154명이었고 K. pneumoniae의 ciprofloxacin에 대한 내성률은 28.6% (44/154)였다. Ciprofloxacin 내성균주 중 ESBL 생성균주의 비율은 95.5% (42/44)였고 ciprofloxacin 감수성균주에서 ESBL 생성균주의 비율은 24.5% (27/110)였다(P<0.001). ESBL생성외에 단변량 분석에서 유의한 관련을 보인 변수로는 남자, 나이가 많은 경우, 패혈증 당시 중환자실 재원, 기저질환이 고형암, 혈액암, 담도계 질환인 경우, 패혈증 발생이전 1달 이내의 항생제 사용력, 3세대 cephalosporin, metronidazole, fluroquinolone, carbapenem 투여력이 있었다. 다변량 로지스틱 분석을 시행 하였을 때는 나이가 많은 경우(Adjusted odds ratio[A0R]; 1.04, 95%confidence interval[CI]; 1.01-1.06)와 ESBL 생성(AOR; 81.35, 95% CI; 17.76-372.53)이 유의하게 ciprofloxacin 내성과 관련이 있었다. 결론 : 패혈증을 일으킨 병원획득 K. pneumonias에서의 ciprofloxacin 내성은 ESBL 생성과 유의한 관련을 보였고 향후 이에 관련된 원인이나 기전을 분석하기위한 분자역학적·분자생물학적 연구가 필요하겠다. Background : Strains of ciprofloxacin-resistant Klebsiella pneumoniae have emerged worldwide. We investigated the epidemiology of ciprofloxacin resistance and its relationship to ESBL production in nosocomial K. pneumoniae bacteremia. Materials and Methods : Using the computerized database of clinical microbiology, we identified all patients whose blood culture had yielded K. pneumoniae between January 2001 and December 2002 at a 2200-bed university-affiliated tertiary-care hospital. During the study period, total of 392 episodes of K. pneumoniae bacteremia were documented of which 163 episodes were acquired nosocomially. 9 cases of recurrent episodes were excluded. Results : The resistance rates to ciprofloxacin was 28.6% (44/154). ESBL-production was significantly more common in ciprofloxacin-resistant isolates than in ciprofloxacin-susceptible isolates (95.9% [42/44] vs. 24.5% [27/110], P<0.001). In univariate analysis, following factors were significantly associated with resistance to ciprofloxacin: older age, male sex, ICU admission at the time of bacteremia, prior use of antibiotics within 1 month before bacteremia, solid tumor, hematological malignancy, or biliary disease as underlying disease, and ESBL-production. The prior use of 3^(rd)-generation cephalosprins, metronidazole, fluroquinolone, or carbapenem were also risk factors. Independent risk factors for ciprofloxacin resistance were older age (adjusted odds ratio [AOR]; 1.04, 95% confidence interval [CI]; 1.01-1.06) and ESBL production (AOR; 81.35, 95% CI; 17.76-372.53). Conclusion : The close relationship between ciprofloxacin resistance and ESBL production was documented in nosocomial K. pneumoniae bacteremia. Further epidemiological and molecular studies to determine factors and mechanisms involved in the relationship are needed.

Caffeine이 지구성 운동 수행능력에 미치는 영향과 억제성 아미노산에 의하여 활성화되는 이온통로의 조절작용

김은경,김영표,천병옥,이계영,김연정,임백빈,조영욱,김창주,김성수 대한스포츠의학회 1999 대한스포츠의학회지 Vol.17 No.1

To investigate the effect and mechanism of caffeine on endurance exercise, two experiments were performed. First, to test caffeine effect on aerobic exercise, 200-300g Sprague-Dawley rats were used and three groups, control group, low caffeine injection group and high caffeine injection group, were divided. Blood smpling by heart puncture were done at rest, after 30 min treadmill exercise, and after maximal exercise. Blood glucose, free fatty acid concentration were detected and following results were obtained. Glucose concentration showed significant difference between groups(p=0.0305) and also significant changes were exhibited between time(p=0.0004). Free fatty acid concentration had no difference between groups. but had significance between times(p=0.00065). Exercise endurance performance time showed significant difference(p=0.02350 in high caffeine injection group compared to control group. In this experiments, endurance exercise capacity was increased by caffeine injection. Therefore, second experiment was performed to investigate the effect of caffeine on ion current induced inhibitory amino acid neurotransmitter. GABA and glycine. Single periaqueductal gray neuron was acutely dissociated and nystatin perforated patch clamp was performed under voltage clamping condition. Caffeine evoked outward current in PAG neuron dose dependent manner. 1mM of caffeine application had no response. but 3mM caffeine evoked about 32.5±8.539pA outward ion current and 10mM caffeine evoked about 215.46±19.4pA outward current. 10^-2mM GABA activated Cl￣current and recorded by inward current. Caffeine inhibited GABA activated Cl￣ current concentration dependent manner. 10^-2mM of caffeine had no effect on 1-^-2mM of GABA response. but 10^-1mM caffeine inhibited GABA activated Cl￣ current about 5.74±2.13%, 1mM caffeine inhibited about 17.25±2.70%, 10mM caffeine inhibited GABA response about 45.31±7.71%. 10^-1mM of glycine activated Cl￣ current and also recorded by inward current. Caffeine inhibited glycine activated Cl￣ current concentration dependent manner. 10^-2mM caffeine decreased glycine activated Cl￣ current about 4.61±1.650%, 10^-1mM caffeine decreased about 6.49±2.24%, 1mM caffeine decreased about 26.82±4.27%, and 10mM caffeine decreased glycine response about 94.47±1.39%. These results suggest that caffeine inhibite inhibitory amino acid, GABA and glycine, this response causes excitation of CNS and this seems to be the basic mechanism of increasing effect to aerobic exercise performance by caffeine.

간 세포암에서 VEGF, TGF-β1, b-FGF 발현의 의의

김성용,남충현,주종우,채만규,백무준,이문수,김형철,안현철,김홍수,김창진,김창호 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.1

Purpose: Angiogenesis is important for the proliferation and the metastasis of solid tumors. The growth of a solid tumor is widely recognized to depend on the process of neovascularrozation. Without angiogenesis, tumors cease to grow beyond even a few milimeters in diameter. It has been shown that tumor vascular density is an independent prognostic marker in several types of human tumors and is known to correlate with poor prognosis. To date, many angiogenic factors have been identified, such as transforming growth factor-α(TGF-α), transforming growth factor-β(TGF-β), fibroblast growth factor family(FGF), vascular endothelial growth factor(VEGF), platelet derived endothelial cell growth factor(PD-ECGF), tumor necrosis factor-α(TNF-α), and angiogenin. Hepatocellular carcinoma(HCC) is the second most common tumor in Korean males and is known as a typical hypervascular tumor with frequent portal vein invastion. The authors identified the expreesion of VEGF, TGF-β1, and b-FGF in HCC specimens and evaluated the relationship between these growth factors and the clinicopathologic characteristics of HCC. Method: We reviewed the medical records of 30 patients who were diagnosed as hepatocellular carinoma treated with hepatic resection between January 1994 and December 1998 in Soonchunhyang University Chunan Hospital. The selection of the cases was decided according to the condition of paraffin block fixation. The prognostic factors such as age, sex, tumor size, concentration of serum α-fetoprotein, presence of liver cirrhosis, presence of tumor emboli in portal vein, TMN stage, amount of transfusion during the operation, hepatitis B virus(HBV) infection, and Edmonson-Steiner(E-S) grade were investigated. Relationship between the prognostic factors and the immunopathologic expression of the TGF-β1, b-FGF, and VEGF was examined. Result: Thirty patients (24 males, 6 females) were included in the current study. The patient's mean age was 50.6 years and the age ranged from 36 to 65 years. The mean size of the tumor was found to be 5.2cm. All the patients were follewed up for 7 to 63 months. Child's classification A patients were 23(76.7%)cases, B patients were 7(23.3%)cases, and C was none. Immunohistochemical staining of HCC tumor mass in VEGF expression patients were 17(56.7%), b-FGF expression patients were 10(33.3%), and TGF-β1 expression patients were 10(33.3%). VEGF expression or more than one positive expression among the three factors correlated with tumor size and the stage of HCC but did not correlated with other clinicopathological characteristics. TGF-β1 and b-FGF did not correlate with any clinicopathological characteristics. Conclusion: The results suggest that the expression of VEGF or more than one positive expression among the three factors in HCC cells may be a significant prognostic factor of HCC.

혈우병 환자에 동반된 자발성 후복막강 출혈

김광일,김동호,우상민,이석주,김홍성,조인성,윤환중,조덕연,김삼용 충남대학교 의과대학 지역사회의학연구소 1997 충남의대잡지 Vol.24 No.1

Spontaneous retroperitoneal hemorrhage due to hemophilia A with impaired coagulopathy is very rare. Spontaneous retroperitoneal hemorrhage has been recorded as having originated from many retroperitoneal organs and blood vessels, and it may be due to local and/or systemic factors. In the majority of the patients, kidney and adrenal gland were the major site of hemorrhage. The systemic causes of spontaneous retroperitoneal hemorrhage are anticoagulation therapy and chronic hemodialysis. During the course of these treatments, hemorrhagic complications may occur at many site, including the retroperitoneal space. Blood dyscrasias including leukemia, polycythemia, sickle cell trait and hemophilia have been reported associated with spontaneous retroperitoneal hemorrhage. We report a case of spontaneous retroperitoneal hemorrhage occurred in a gemophilia A patient with brief review of literature