• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 제38회 하계학술대회
• /
• pp.1508-1509
• /
• 2007

본 논문에서는 TSMC 0.18um공정을 이용한 무선통신 수신기용 직접변환 방식의 Double Balanced Mixer를 설계 하였다. 제안된 mixer는 current bleeding기법과 내부에 인덕터를 추가하여 기존의 Gilbert Cell구조의 mixer에 비해 변환 이득과 Flicker Noise특성을 향상 시켰다. 모의실험결과 2.45GHz에서 11dB의 변환이득을 나타내었으며 Flicker Noise의 corner frequency는 510kHz이고 이때 잡음특성은 10.8dB이다. 이 회로의 동작전압은 1.8V이며 소모 전력은 8.8mW이다.

• Journal of Chest Surgery
• /
• 제16권3호
• /
• pp.322-330
• /
• 1983

TAPVC represents 1 to 4% of all congenital cardiac defects. Generally severe and refractory cardiac failure develops in the majority of patients in the early infancy. In a small minority of patient, they are relatively asymptomatic in infancy, but symptoms will develop of necessity In the later life. Our three cases had dyspnea on exertion and cyanosis and had a history of frequent respiratory infections. All 3 cases had the typical showman configuration on roentgenograms of the chest. Current surgical therapy has greatly altered the unfavorable course of these patients after institution of extra-corporeal circulation. We have experienced three cases from June, 1973 to May, 1983, the patients were undergone complete repair with extracorporeal circulation at the Department of Thoracic and Cardiovascular Surgery in the Yonsei University. The ages ranged from 12 years to 14 years, all cases were supracardiac type of TAPVC. Only one case died due to bleeding from anastomosis site between LA and pulmonary venous trunk. In the remaining two patients with complete corrections of TAPVC, there was excellent relief of symptoms such as dyspnea and cyanosis. Their postoperative course have been good during follow-up.

• 한국임상약학회지
• /
• 제9권1호
• /
• pp.27-34
• /
• 1999

The goal of oral anticoagulation therapy with warfarin is to maintain INR values within the therapeutic range in order to prevent complications such as bleeding and thrombosis. The purposes of this study were to investigate the current level of anticoagulation control using INR values, to investigate the incidences of thromboembolism and bleeding complications, and to compare the effect of low intensity INR regimen with therapeutic range recommended by ACCP (American College of Chest Physician). Two hundred three patients with mechanical heart valve replacement done at Yonsei University Cardiovascular Center between January 1994 and December 1996 were selected and reviewed retrospectively. The target INR ranges of $2.5\sim3.5$ (ACCP standard) and low intensity INR of $2.0\sim3.5$ were used for evaluation. According to ACCP standard, $51.2\%$ of patients and $31.1\%$ of INR values were within the therapeutic range when average INR and cumulative INR were used, respectively. Applying low intensity INR values of $2.0\sim3.5$, the therapeutic control was achieved in $57.4\%\;and\;90.1\%$, using average INR and total INR, respectively. The incidences of major and minor bleedings were $0.5\%\;and\;26.6\%$, respectively. The incidence of thromboembolism was $0.5\%$. There was no significant difference in terms of complication incidences between INR $2.0\sim2.5\;and\;INR\;2.5\sim3.5$ groups. However, INR values at the time of bleeding were generally high. In conclusion, the evaluation of patients with mechanical heart valve replacement showed low level of therapeutic control with warfarin therapy. This is partially explained by the fact that the physicians at Yonsei University Cardiovascular Center were using lower intensity INR values as a goal than recommended INR. Also, in the near future, systematic anticoagulation service should be implemented at various hospitals in Korea so that patients on anticoagulant therapy can be more closely monitored to be within the recommended INR by ACCP.

• 콘크리트학회논문집
• /
• 제22권3호
• /
• pp.419-426
• /
• 2010

이 논문에서는 포스트텐션 구조물에 적용되는 그라우팅 품질확보를 위한 재료개선 및 실험과정을 기술하였다. 그라우팅이란 강연선이 삽입된 덕트를 시멘트물질로 채우는 공정이다. 국내에서는 아직 그라우팅의 품질과 포스트텐션 구조물의 내구성에 대한 관계가 인식되지 않아 적절한 품질관리에 어려움이 있다. 국내표준시험법은 강연선에 의한 심지효과(wick effect)를 고려하지 않기 때문에 시공 시 발생할 수 있는 재료분리량을 평가하기 어렵다. 따라서 현 품질기준을 만족하는 그라우트를 사용하더라도, 시공 시 과다한 불리딩 수나 재료수축이 발생할 수 있다. 이 연구에서는 그라우트에 관련된 해외기준과 표준시험법을 조사하여 국내기준 및 표준시험법과 비교한 후 해외기준에 준하는 성능을 나타낼 수 있는 그라우트 구성성분비 및 혼화제를 제시하여 보았다. 개선된 그라우트의 성능을 해외표준시험법에 따라 일반적으로 적용되고 있는 그라우트재와 비교하였으며 PC빔의 덕트형상을 고려한 목업시험을 통하여 흐름유형(flow pattern) 및 충전성능을 관찰하였다. 이 실험을 통하여 그라우팅의 성능은 재료특성에 의하여 높은 영향을 받으며 적용 대상의 기하학적 형상에 따라 상이한 충전특성을 가진다는 것 알 수 있었다.

• 한국전자파학회논문지
• /
• 제21권4호
• /
• pp.443-451
• /
• 2010

본 논문에서는 Band-III 지상파 디지털 멀티미디어 방송 수신용 저전력 CMOS RF 튜너 칩에 대해 기술한다. 제안된 RF 튜너 칩은 저전력의 소형 휴대단말기 개발에 적합한 Low-IF 수신 구조로 설계되었으며, 174~240 MHz의 RF 방송 신호를 수신하여 1.536 MHz 대역폭의 2.048 MHz IF 신호를 출력한다. RF 튜너 칩은 저잡음 증폭기, 이미지 신호 제거 믹스, 채널 필터, LC-VCO, PLL과 Band-gap 기준 전압 생성기 등의 모든 수신부 기능 블록들을 포함하고 있으며, 0.18 um RF CMOS 기술을 이용하여 단일 칩으로 제작되었다. 또한 전력 소모를 줄이기 위한 4단계 이득 가변이 가능한 저잡음 증폭기를 제안하였으며, Schmoock's 선형화 기법과 Current bleeding 회로 등을 이용하여 수신 성능을 개선하였다. 제작된 RF 튜너 칩의 이득 제어 범위는 -25~+88 dB, 잡음 특성(NF)은 Band-III 전체 대역에서 약 4.02~5.13 dB, 선형 특성(IIP3)은 약 +2.3 dBm 그리고 이미지 신호 제거비는 최대 63.4 dB로 측정되었다. 총 전력 소모는 1.8 V 단일 전원에서 약 54 mW로 우수하며, 칩 면적은 약 $3.0{\times}2.5mm^2$이다.

• Journal of Chest Surgery
• /
• 제9권2호
• /
• pp.271-275
• /
• 1976

Truncus arteriosus is a rare and highly lethal cardiac anomaly characterized by a single arterial trunk emerging from the heart and supplying the coronary, systemic, and pulmonary circulations, The first successful correction of truncus arteriosus was reported by McGoon et al. in 1968 and was based on experimental work reported by Rastelli et al. in 1967 in which a conduit consisting of a homograft of the ascending aorta and aortic valve was used to establish continuity between the right ventricle and the pulmonary arteries, Modification of this procedure using a Dacron tube valved with porcine xenograft instead of a homograft have resulted in the current definite treatment for truncus arteriosus. This report describes an 3 years and 4 months old boy with heart failure from type I truncus arteriosus who was diagnosed as the V. S. D. with pulmonary hypertension preoperatively and underwent corrective surgery employing the Rastelli procedure using a Dacron conduit valved with canine xenograft, but died due to massive bleeding from the anastomosis sites in operating room.

• Journal of Chest Surgery
• /
• 제24권2호
• /
• pp.143-152
• /
• 1991

From 1983, until June, 1990, 10 patients with various type of truncus arteriosus underwent total surgical correction including Rastelli procedure at Seoul National University Hospital. The age at operation ranged from 1 month to 9 years [mean 2.1 years]. Six patients had truncus type I, 3 patients had truncus type II, and one patients had truncus type IIIc. Right ventricular pulmonary artery continuity was established with a porcine valved conduit in 6 patients, mechanical valved conduit in 1 patient, and bovine pericardial conduit in 3 patients. The postoperative right ventricular /left ventricular pressure ratio ranged from 0.4 to 0.71 [mean 0.51${\pm}$0.14]. The lung histology revealed grade II pulmonary obstructive disease even at 4 month of age. Five patients were dead in hospital [50%], and they were less than 2 year of age. One patient, who had severs congestive heart failure preoperatively, died of low output syndrome and the other died of low output syndrome with postoperative bleeding. There were three death, because of a pulmonary hypertensive crisis that might have been prevented. Two of the five survivors had conduit failure over a mean follow up of 42 months [range 1 to 78 months]. Obstructed conduit was removed and a new conduit constructed using the conduit bed as the posterior wall and the patch of bovine pericardium and Dacron as patch the roof of the conduit. One patient died of acute cardiac failure during the operation. Although results in infants less than 2 years old have not been good, current improvement of intra-and postoperative care suggested that prompt repair is indicated for infants with truncus arteriosus.

• The Korean Journal of Pain
• /
• 제12권2호
• /
• pp.227-230
• /
• 1999

The sphenopalatine ganglion lies behind the middle nasal concha in the sphenopalatine foramen which connects the fossa to the nasal cavity. It has sympathetic and parasympathetic fibers as well as sensory fibers which innervate the nasal cavity, palate and nasopharynx. Current indications for blockade of the sphenopalatine ganglion include the management of migraine, cluster headache and a variety of facial neuralgias. Blockage of this ganglion can be attempted when more conservative treatments have failed. If the pain relief gained through the procedure is of short duration and the blockage needs to be repeated frequently, then radiofrequency thermocoagulation should be considered. Since the sphenopalatine ganglion lies close to the maxillary nerve, neurolytics can cause facial dysesthesia, radiofrequency thermocoagulation is the preferred method for ganglionotomy. Radiofrequency thermocoagulation of the sphenopalatine ganglion was done for 3 patients who suffered from postherpetic neuralgia, cluster headache, atypical facial pain respectively. Good results were obtained with the exception of the patient suffering from atypical facial pain. Although we were concerned about complications such as epistaxis, none were encountered. However it should be noted that caution must be exercised when repeatedly redirecting the cannula in the sphenopalatine fossa as serious bleeding and pronounced facial swelling may result.

• 대한암한의학회지
• /
• 제12권1호
• /
• pp.83-89
• /
• 2007

Chemotherapy has many known side effects. Neuropathy is a common side effect when using cisplatin. The clinical course varies and depends on the agents used and their cumulative dose. Although symptoms can resolve completely, in most patients chemotherapy-induced peripheral neuropathy is either only partially reversible or completely irreversible. Current management for chemotherapy-induced peripheral neuropathy is symptomatic relief using membrane stabilizing medications and antidepressants. Dysaesthesia and pain involving the feet and hands are described in traditional korean medicine. In traditional korean medicine, the pathogenesis is related to the inability to direct Qi and Blood to the extremities, and is associated with Qi, Blood, Yang and Kidney deficiencies. We report a case of a 52 years old female patient treated with acupuncture and bleeding treatment for the goal of improving the symptoms of chemotherapy induced peripheral neuropathy. Further study and other medical method will be needed in order to improve the effect and determine the long-term effect of traditional korean medicine in treating Chemotherapy-induced Peripheral Neuropathy.

• BMB Reports
• /
• 제46권10호
• /
• pp.484-489
• /
• 2013

Piperlonguminine (PL), an important component of Piper longum fruits, is known to exhibit anti-hyperlipidemic, antiplatelet and anti-melanogenic activities. Here, the anticoagulant activities of PL were examined by monitoring activated-partial-thromboplastin-time (aPTT), prothrombin-time (PT), and the activities of thrombin and activated factor X (FXa). The effects of PL on the expressions of plasminogen activator inhibitor type 1 (PAI-1) and tissue-type plasminogen activator (t-PA) were also tested in tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) activated HUVECs. The results showed that PL prolonged aPTT and PT significantly and inhibited the activities of thrombin and FXa. PL inhibited the generation of thrombin and FXa in HUVECs. In accordance with these anticoagulant activities, PL prolonged in vivo bleeding time and inhibited TNF-${\alpha}$ induced PAI-1 production. Furthermore, PAI-1/t-PA ratio was significantly decreased by PL. Collectively, our results suggest that PL possesses antithrombotic activities and that the current study could provide bases for the development of new anticoagulant agents.