전도성 아연/에폭시 수지 복합체의 전기적 특성

박재경(Jae Kyung Park),이정은(Jung Eun Lee),최태운(Tae Un Choi),홍기헌(Ki Heon Hong),오승민(Seung Min Oh),오대희(Dae Hee Oh) 한국고분자학회 2015 폴리머 Vol.39 No.6

에폭시 수지에 아연 분말을 분산시켜 전도성 복합재료를 제조하여 충전제의 함량별 체적 전기저항과 미세경도, 미세구조, 열적 성질 등을 조사하였다. 아연/에폭시 수지 복합체의 체적 전기저항은 8.8×10⁶~4.4×10³Ω·㎝의 범위를 나타내었다. 아연함량이 70 wt%인 lower 관투전이 영역에서 upper 관투전이 영역인 78 wt%까지 체적 전기저항 값이 급격하게 감소하였다. 이는 분말 함량 70 wt% 이상에서부터 전자가 잘 이동할 수 있는 통로가 만들어진 것으로 보인다. 분말 함량이 78 wt% 이상에서는 매트릭스 내의 분말 함량만 늘어날 뿐 체적저항의 감소에는 영향을 주지 않는 것으로 나타났다. 아연/에폭시 수지 복합체의 초미세 경도(DHT) 값은 4.566~6.604로 나타났다. 이것은 매트릭스 내 분말의 함량이 증가할수록 복합체의 DHT 값은 증가하는 것으로 나타났다. 이는 고분자 매트릭스 내에 분말간의 보강효과에 의해 경도가 증가한 것으로 보인다. 전기전도도는 니켈/에폭시 수지 복합체보다 아연/에폭시 수지 복합체가 높았다. 복합체의 경도는 보고된 니켈/에폭시 수지 복합체와 아연/에폭시 수지 복합체는 비슷한 경도를 가진 것으로 나타났다. 아연/에폭시 수지 복합체의 열적 안정성은 400~470 ℃ 사이에서 매트릭스로 사용되어진 에폭시 수지의 분해로 무게 손실이 발생된 것으로 니켈과 아연 복합체 모두 비슷한 온도에서 열분해가 시작되는 것으로 보아서 아연금속 분말의 영향보다 에폭시 매트릭스의 영향을 많이 받는 것으로 사료되어진다. The conductive polymer composites have attracted considerable attention in the field of industry due to their electrical properties. To understand electrical properties of the composites, their volume specific resistance was measured. Electrical conductivity results showed percolation phenomena. Percolation theories are frequently applied to describe the insulator-to-conductor transitions in the composites composed of conductive filler and insulating matrix. It was found that percolation threshold strongly depends on the aspect ratio of filler particles. The critical concentration of percolation formed is defined as the percolation threshold. The purpose of this study was to examine electrical properties of the resins filled with zinc. The sample was prepared using vehicle such as epoxy resin replenished with zinc powder, and the evaluation on their practical use was performed in order to apply them to electric and electronic industry as well as general field. The volume specific resistance of epoxy resin composites was 8.8×10⁶~4.4×10³ Ω·㎝ when using zinc powder. Weight loss of the conductive composites took place at 400~470 ℃.

한국인 중증 외상 환자에서 촬영한 경추 외측면 단순 방사선 영상의 적절성

이경학 ( Kyung Hag Lee ),김영철 ( Yeong Cheol Kim ),최석호 ( Seok Ho Choi ),한국남 ( Gook Nam Han ),이수언 ( Soo Un Lee ),이정은 ( Jung Eun Lee ),서길준 ( Gil Joon Suh ),윤여규 ( Yeo Kyu Yoon ) 대한외상학회 2012 大韓外傷學會誌 Vol.25 No.4

Purpose: The objective of this study was to investigate the appropriateness of the cross table lateral cervical X-ray used in the emergency department for severely traumatized Korean patients. Methods: Patients visiting our institution from May 2011 to May 2012, who had injury severity score (ISS) > 15 and who received a cervical X-ray in the emergency department, were included in this study. Data including demographics, ISS score, GCS score, and place where the x-ray was taken were collected to evaluate their relationship with appropriate coverage of the cervical X-ray. The appropriateness of a cervical cross lateral view Xray was evaluated using exposure of the basion, and the opisthion, as well as the distal level of exposure. Results: Fifty-two patients were included in this study. The identification rate of the basion was 79.2%, and the identification rate of the opisthion was 88.7%. Complete exposure of C7/T1 was accomplished in 3.8% of the patients. The ISS was higher for X-ray taken in the trauma bay, but the range of exposure showed no difference between the places where the X-rays taken. Patients who had exposure of C 5/6 or more had lower body weight and body mass index (BMI) compared with unexposed patients. Conclusion: In severely traumatized Korean patients, the adequacy of the cross table lateral cervical X-ray was inappropriate in most cases. No difference was observed in the exposure range between the places where the X-rays were taken, and patients with less exposure showed higher body weight and higher BMI. (J Trauma Inj 2012;25:241-246)

실험연구 : Thiopental Sodium, Propofol, Midazolam과 Ketamine의 흰쥐 동맥내피인자에 대한 효과

강봉진 ( Bong Jin Kang ),이정은 ( Jung Un Lee ),손수창 ( Soo Chang Son ),강포순 ( Po Sun Kang ) 대한마취과학회 2003 Korean Journal of Anesthesiology Vol.44 No.5

임상연구 : 부인과적 복강경하수술 시 전신마취 방법에 따른 혈역학적 변화

이영재 ( Young Jae Lee ),이정은 ( Jung Un Lee ) 대한마취과학회 2006 Korean Journal of Anesthesiology Vol.51 No.2

Background: The purpose of our study is to evaluate the hemodynamic changes during the use of different general anesthetic methods in laparoscopic gynecologic surgery. Methods: 45 women undergoing laparoscopic gynecologic surgery were randomly divided into 3 groups. The first group, called group P, used propofol for general anesthesia. The second group, called group D, used desflurane and the third group, called group S, used sevoflurane. The hemodynamic parameters HR (heart rate), MBP (mean blood pressure), CO (cardiac output), SV (stroke volume), CI (cardiac output), and SVR (systemic vascular resistance) were obtained 7 times by using a partial CO2 rebreathing method and an automated blood pressure device. Results: In the group D and group P, HR decreased significantly reaching the head-down position and CO2 insufflation. In the all groups, the MBP increased significantly after reaching the head-down position and CO2 insufflation. There were no, significant differences among the groups in this test. In the all groups, CO, SV and CI decreased significantly after reaching the head-down position and CO2 insufflation, followed by a slight recovery to near-normal values or higher than normal after CO2 deflation, with the exception of group P. SVR increased significantly after reaching the head-down position and CO2 insufflation, followed by a slight recovery to near-normal values or higher than normal after CO2 deflation. Conclusions: Laparoscopic gynecologic surgery with CO2 insufflation induces significant hemodynamic changes including increases of MBP, SVR and reduction of HR, CO, SV, CI (P < 0.05). These changes are especially significant in group P, used propofol except MBP (P < 0.05). But these changes of group P were all within normal limits. (Korean J Anesthesiol 2006; 51: 139-46)

실험연구 : Methylmethacrylate Monomer의 흰쥐 기관 평활근 이완 효과

길현주 ( Hyun Jue Gill ),이정은 ( Jung Un Lee ),김윤희 ( Yoon Hee Kim ),양현정 ( Hyun Jung Yang ) 대한마취과학회 2007 Korean Journal of Anesthesiology Vol.52 No.2

Background: Methylmethacrylate monomer (MN) bone cement is commonly employed in orthopedic procedures, particularly total hip and knee replacement, to anchor prosthetic devices to bone. Numerous cardiopulmonary complications can occur just after injection of MN. And MN produces direct relaxation of vascular smooth muscle in vitro. The purpose of this study was to determine if MN could have relaxation effect in tracheal smooth muscle too. Methods: Each ring of rat trachea was suspended on wire supports in a bath with Tris Tyrode solution. Dose response curves of MN were recorded after contraction of tracheal ring with acethylcholine (Ach) 10-5 M or cabachol (Cch) 10-8 M. MN was administered in denuded tracheal rings and compared it`s effect with intact tracheal rings to see the effect of epithelium for contraction. And MN dose response curves were recorded after pretreatment of nitric oxide synthase inactivator (L-NAME), muscarinic receptor blocker (atropine), beta-adrenaline receptor blocker (propranolol), adenylyl cyclase inhibitor (SQ22536) respectively. The effects of MN on cellular Ca2+ and K+ migration in rat tracheal preparations were studied. Results: MN significantly inhibited acetylcholine or carbachol induced contractions of tracheal rings dose-dependently (P < 0.05). This relaxation effect of MN was not recovered in denuded tracheal rings. And pretreatment with L-NAME, propranolol, atropine, SQ22536 or tetraethylammonium respectively did not recover the relaxation effect of MN. MN inhibited both intracellular calcium release and extracelluar calcium influx. Conclusions: The relaxation effects of MN on rat tracheal rings are not related with epithelium, nitric oxide, muscarinic, or beta-adrenergic receptor. Methylmethacrylate monomer inhibits both intracellular calcium release and extracelluar calcium influx. (Korean J Anesthesiol 2007; 52: 194~201)

임상연구 : 복강경하 부인과 수술 시 Esmolol, Esmolol과 Nicardipine 및 Remifentanil의 투여가 평균동맥압, 심박수 및 회복에 미치는 영향

이호영 ( Ho Young Lee ),권우진 ( Woo Jin Kwon ),이정은 ( Jung Un Lee ) 대한마취과학회 2008 Korean Journal of Anesthesiology Vol.55 No.6

Background: The purpose of this study was to compare the effects of esmolol, esmolol and nicardipine or remifentanil on MBP, HR and recovery in gynecologic laparoscopic surgery. Methods: Eighty patients scheduled for gynecologic laparoscopic surgery were randomly allocated to four groups: group C (control group, n = 20); group E (esmolol group, n = 20) received esmolol 1 mg/kg, followed by 5 μg/kg/min; group EN (esmolol + nicardipine group, n = 20) received esmolol 1 mg/kg and nicardipine 15 μg/kg, followed by an esmolol infusion 5 μg/kg/min; and group R (remifentanil group, n = 20) received remifentanil 1 μg/kg, followed by 0.05 μg/kg/min. The MBP and HR were measured at preinduction, after induction, at 1, 3, 5 min after intubation, before and after insufflation of CO2 and during surgical procedures. Recovery profiles and postoperative side effects were assessed. Results: The change of MBP after intubation was significantly decreased in group EN. The change of HR after intubation and during surgical procedure were significantly decreased in group E and group R. Recovery profiles were significantly faster in all study groups compared with group C. Conclusions: The use of esmolol in combination with nicardipine was effective in preventing the increase of MBP after intubation, whereas esmolol or remifentanil had attenuated the acute change of HR to noxious stimuli. Also the use of esmolol, nicardipine or remifentanil as an adjuvant to sevoflurane-N2O anesthesia in gynecologic laparoscopic surgery had facilitated the recovery. (Korean J Anesthesiol 2008; 55: 709~15)

임상연구 : 근이완제 투여 없이 Propofol과 Remifentanil만을 사용한 기관내삽관

정봉찬 ( Bong Chan Jung ),이정은 ( Jung Un Lee ) 대한마취과학회 2006 Korean Journal of Anesthesiology Vol.50 No.6

Background: Using alfentanil followed by an anesthetic induction dose of propofol provides adequate conditions for tracheal intubation without neuromuscular blocking drugs in most patients. Providing an option for intense opioid effect without compromising recovery after short operations, remifentanil might offer benefits over alfentanil. In this study intubating conditions after remifentanil-propofol were evaluated. Methods: Sixty healthy premedicated patients were divided randomly into 3 groups. Anesthesia was intravenously induced with propofol (4μg/ml) followed by remifentanil. Group R2, R3, R4 received 2, 3, 4μg/kg remifentanil, respectively. Ninety seconds after the administration of remifentanil, laryngoscopy and intubation were attempted. Intubation conditions were assessed as excellent, good or poor. The hemodynamic changes were measured at preinduction (base), preintubation, postintubation (immediately, 3 minute, 5 minute after intubation). Results: Clinically acceptable intubating conditions were observed in 65%, 95%, and 95% of patients in the R2, R3, and R4 groups, respectively. Clinically acceptable intubating conditions were significantly (P < 0.05) less likely to occur in Group R2. The mean arterial pressure decreased immediately after induction in all groups. There was no significant elevation in heart rate after tracheal intubation in all groups. There were no significant differences among groups. Conclusions: Healthy, premedicated patients with favorable airway anatomy can be reliably intubated with good or excellent conditions 90 seconds after the administrations of remifentanil 3-4μg/kg and propofol. (Korean J Anesthesiol 2006; 50: 623~8)

골반골에 발생한 방사선속발 골육종 1 예

도영록(Young Rok Do),이춘식,이정은(Jung Un Lee),이원식(Won Sik Lee),송홍석(Hong Suk Song),남성진(Sung Jin Nam) 대한내과학회 1998 대한내과학회지 Vol.54 No.1

Most osteosarcomas arise spontaneously, but rarely they may be secondary to other benign osseous conditions and may occur following irradiation. Postradiation sarcoma of bone is approximately 5.5 percent of all osteogenic sarcoma. Diagnosis is possible when a sarcoma arising after long latent period(more than 3 years) in irradiated bone and the bone is normal or benign osseous lesion at the time of irradiation. The spontaneously arising osteogenic sarcomas are distribute mainly in the knee region, but postradiation sarcoma arise in any bones, such as long bone of the extremity, pelvic bone, vertebra, craniofacial bone and shoulder girdle bone. Recently we experienced a case of postradiation osteosarcoma of the pelvic bone who recieved radiation therapy for carcinoma of the uterine cervix 20 years ago.

임신한 당뇨환자에서 인슐린 lispro 투여로 저혈당을 예방한 2 예 보고

임문환(Moon Whan Im),박운호(Un Ho Park),이정은(Jung Eun Lee),고선환(Sun Hwan Koh),임수빈(Soo Bin Im),이정례(Jeong Rye Lee),이지영(Ji Young Lee),황성욱(Sung Ook Hwang),이우영(Woo Young Lee) 대한산부인과학회 2002 Obstetrics & Gynecology Science Vol.45 No.7

Insulin therapy is indicated in the treatment of gestational diabetic women and overt diabetic pregnant women for hyperglycemia after failure to respond to the diets and exercise regimens. The insulin is administered to mimic normal pancreatic function. The normal pancreas secretes 50% of the total daily insulin as mealtime boluses. This delivery may be mimicked by four-injection-per-day of combination of NPH and regular insulin (RI). Hypoglycemia is a well-recognized complication of intensive insulin therapy in patients with Type Ⅱ diabetes. Recently, it has been reported that insulin-lispro, an analogue of regular human insulin with a peak insulin action achieved with a 1 hour after injection improves postprandial glucose concentration in non-pregnant diabetic patients. Treatment of gestational or diabetic pregnant women with NPH and insulin-lispro has significantly lower postprandial glucose levels without an increase in hypoglycemic events. Here, we report 2 cases of hyperglycemic control with four times daily administration of NPH & insulin-lispro on diabetes in pregnancy, with brief reviews.

이달의 X-선 : 전폐세척술로 호전된 폐포단백증 2예

정성수 ( Seong Su Jeong ),강동원 ( Dong Won Kang ),이규승 ( Kyu Seung Lee ),고동석 ( Dong Seok Ko ),서재철 ( Jae Chul Suh ),김근화 ( Geun Hwa Kim ),김진환 ( Jin Whan Kim ),이정은 ( Jung Un Lee ),김주옥 ( Ju Ock Kim ),김선영 ( Sun 대한결핵 및 호흡기학회 1999 Tuberculosis and Respiratory Diseases Vol.47 No.3