• Journal of Korean Neurosurgical Society
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• 제62권2호
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• pp.136-143
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• 2019

Moyamoya disease (MMD) is a progressive cerebrovascular disease with unknown etiology, characterized by bilateral steno-occlusive changes at the terminal portion of the internal carotid artery and an abnormal vascular network formation at the base of the brain. MMD has an intrinsic nature to convert the vascular supply for the brain from internal carotid (IC) system to the external carotid (EC) system, as indicated by Suzuki's angiographic staging. Insufficiency of this 'IC-EC conversion system' could result not only in cerebral ischemia, but also in intracranial hemorrhage from inadequate collateral anastomosis, both of which represent the clinical manifestation of MMD. Surgical revascularization prevents cerebral ischemic attack by improving cerebral blood flow, and recent evidence further suggests that extracranial-intracranial bypass could powerfully reduce the risk of re-bleeding in MMD patients with posterior hemorrhage, who were known to have extremely high re-bleeding risk. Although the exact mechanism underlying the hemorrhagic presentation in MMD is undetermined, most recent angiographic analysis revealed the characteristic angio-architecture related to high re-bleeding risk, such as the extension and dilatation of choroidal collaterals and posterior cerebral artery involvement. We sought to update the current management strategy for hemorrhagic MMD, including the outcome of surgical revascularization for hemorrhagic MMD in our institute. Further investigations will clarify the optimal surgical strategy to prevent hemorrhagic manifestation in patients with MMD.

• 대한영상의학회지
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• 제81권4호
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• pp.852-862
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• 2020

인터벤션 색전술은 영상 유도하에 카테터를 출혈 부위에 위치하고, 젤폼 또는 코일 등의 색전 물질을 사용해서 출혈을 막는다. 의인성 외상을 치료하는 것 이외에, 수술이 불가능한 간 및 신장의 출혈(blush-bleeding) 및 혈관 손상을 진단하고 치료하는 데에 유용하다. 그러나 병원 일과 시간이 아닌 경우, 숙련된 인터벤션 의료팀이 항상 준비되어 있지는 않다. 이러한 상황에서 인터벤션 팀의 협업은 심각한 손상을 입은 환자를 빠르게 치료하는데 꼭 필요하다. 이 논문은 가상 투시장비 검사의 유용성에 대한 현재의 원칙과 기술을 검토하고 응급 인터벤션 시술에서 유용한 사례들을 제시하고자 한다.

• 대한전자공학회논문지SD
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• 제47권3호
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• pp.51-57
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• 2010

IEEE 802.11n 기반 무선 LAN과 IEEE 802.16e 기반 Mobile WiMAX에 적용할 수 있는 이중모드 직접 변환 수신기를 $0.13\;{\mu}m$ RF CMOS 공정을 이용하여 설계하였다. 설계된 직접 변환 수신기는 2.3-2.7 GHz의 주파수 범위에서 동작을 한다. 저잡음 증폭기에 Current Steering 기술을 사용하여 전체 이득의 크기를 3 단계로 조절이 가능하게 하였다. 플리커 잡음 영향을 낮추기 위해 믹서에 Current Bleeding 기술을 사용하였다. 믹서 LO를 위한 I/Q 위상 신호 발생을 위해 주파수 2-분주회로를 포함하였다. 제작된 직접 변환 수신기는 1.4V의 공급 전원에서 LO 버퍼를 포함하여 56 mA를 사용하며, 32 dB의 전력이득과 4.8dB의 잡음지수, 그리고 +6 dBm의 출력 $P_{1dB}$를 가진다.

• International Journal of Arrhythmia
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• 제17권1호
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• pp.41-45
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• 2016

Atrial fibrillation (AF) can occur in acute coronary syndrome (ACS), which is a serious medical condition and may require the use of antiplatelet agents in addition to anticoagulants for stroke prevention. Recently, novel or non-vitamin K antagonist oral anticoagulants (NOACs) have been increasingly used for stroke prevention in patients with AF instead of traditional OACs. The duration of treatment or treatment with a stepwise approach (e.g. triple, double, or monotherapy) is determined depending on the clinical setting and the balance between the risks of ischemic stroke and bleeding. However, some concerns and controversies in the use of NOACs in patients with AF and ACS need to be addressed. Here, the current management for NOAC therapy in patients with ACS and AF will be reviewed based on recently published guidelines.

• Journal of Korean Neurosurgical Society
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• 제60권3호
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• pp.301-305
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• 2017

Multiloculated hydrocephalus (MLH) is a condition in which patients have multiple, separate abnormal cerebrospinal fluid collections with no communication between them. Despite technical advancements in pediatric neurosurgery, neurological outcomes are poor in these patients and the approach to this pathology remains problematic especially given individual anatomic complexity and cerebrospinal fluid (CSF) hydrodynamics. A uniform surgical strategy has not yet been developed. Current treatment options for MLH are microsurgical fenestration of separate compartments by open craniotomy or endoscopy, shunt surgery in which multiple catheters are placed in the compartments, and combinations of these modalities. Craniotomy for fenestration allows better visualization of the compartments and membranes, and it can offer easy fenestration or excision of membranes and wide communication of cystic compartments. Hemostasis is more easily achieved. However, because of profound loss of CSF during surgery, open craniotomy is associated with an increased chance of subdural hygroma and/or hematoma collection and shunt malfunction. Endoscopy has advantages such as minimal invasiveness, avoidance of brain retraction, less blood loss, faster operation time, and shorter hospital stay. Disadvantages are also similar to those of open craniotomy. Intraoperative bleeding can usually be easily managed by irrigation or coagulation. However, handling of significant intraoperative bleeding is not as easy. Currently, endoscopic fenestration tends to be performed more often as initial treatment and open craniotomy may be useful in patients requiring repeated endoscopic procedures.

• 대한기관식도과학회:학술대회논문집
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• 대한기관식도과학회 1983년도 제17차 학술대회연제순서 및 초록
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• pp.17.5-18
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• 1983

혈관섬유종은 비교적 희귀하며 주로 성장기 남성의 비인강에 발생되고 있으며 병리조직학적으로는 양성이나 임상적으로는 해부학적 위치와 주위조직으로 침윤해 들어가는 파괴성 및 적출시의 출혈성, 불완전한 적출로 인한 재발 때문에 악성으로 알려져 왔다. 흔히 사춘기 이전에서 호발되고 사춘기를 지나서는 발생율이 적은 종양의 하나이며 대부분 비인강에 나타나며 비중격에 생긴 예는 아주 희귀하다. 저자들은 최근에 비중격에 발생한 혈관섬유종 1예를 치험하였기에 보고하는 바이다. 환자는 37세 된 남자로서 1개월 전부터 비폐색과 빈번한 비출혈을 호소하여 본원 이비인후과에 내원하였다. 국소소견상 좌측 비강을 거의 폐쇄하고 있는 종물이 보여 1983년 1월 21일 국소마취하에서 경비적으로 판전적출술을 시행하였다. 술후 3 일째 퇴원하여 현재까지 관찰중이나 별 이상 없이 경과하고 있다.

• Journal of Interdisciplinary Genomics
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• 제4권1호
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• pp.15-18
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• 2022

Hemophilia A is a rare X-linked congenital deficiency of clotting factor VIII (FVIII) that is traditionally diagnosed by measuring FVIII activity. Various mutations of the FVIII gene have been reported and they influence on the FVIII protein structure. A deficiency of or reduction in FVIII protein manifests as spontaneous or induced bleeding depending on the disease severity. Mutations of the FVIII gene provide important information on the severity of disease and inhibitor development. FVIII mutations also affect the discrepant activities found using different FVIII assays. FVIII activity is affected differently depending on the mutation site. Long-range PCR is commonly used to detect intron 22 inversion, the most common mutation in severe hemophilia. However, point mutations are also common in patients with hemophilia, and direct Sanger sequencing and copy number variant analysis are being used to screen for full mutations in the FVIII gene. Advances in molecular genetic methods, such as next-generation sequencing, may enable accurate analysis of mutations in the factor VIII gene, which may be useful in the diagnosis of mild to moderate hemophilia. Genetic analysis is also useful in diagnosing carriers and managing bleeding control. This review discusses the current knowledge about mutations in hemophilia and focuses on the clinical aspects associated with these mutations and the importance of genetic analysis.

• 한국구조물진단유지관리공학회 논문집
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• 제22권4호
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• pp.76-82
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• 2018

PSC 구조에서 덕트 내부의 그라우트는 텐던 부식에 효과적인 부식방어 기재이다. 본 연구에서는 일반적으로 사용되고 있는 그라우트와 낮은 물-시멘트비와 실리카 퓸을 혼입한 그라우트를 대상으로 역학적, 내구적 시험을 수행하였다. 높이 1000mm의 덕트를 이용하여 텐던 시스템을 제작하였으며, 두 가지 그라우트에 대하여 강도, 흡수율, 플로우, 블리딩, 팽창률 등을 평가하였다. 또한 내부 12.7mm 텐던에 대하여 ICM(Impressed Current Method)를 이용하여 2일 및 4일 동안 부식을 촉진시켰으며 부식량을 조사하였다. 개선된 그라우트에서는 10MPa 이상의 높은 강도와 50% 이하의 낮은 흡수율을 나타내었다. 또한 2일~4일 동안의 부식촉진실험에서 39.8%~48.2%의 뛰어난 부식감소율 나타내었다.

• 한국전자파학회논문지
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• 제27권2호
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• pp.220-223
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• 2016

본 논문에서는 캐스코드(cascode) 구조에 트랜지스터를 추가하여 잡음 특성을 유지하면서 높은 선형성을 갖는 저잡음 증폭기 구조를 제안하고 설계하였다. 제안한 구조는 트랜지스터의 사이즈 최적화를 통해 잡음원을 최소화 했으며, 전류원분리(current bleeding) 효과를 주어 선형성을 개선하였다. 저잡음 특성에 유리한 $0.5{\mu}m$ pHEMT 공정을 이용해 제작된 저잡음 증폭기는 1.8~2.6 GHz의 동작 대역에서 30.8 dBm의 $OIP_3$, 15.0 dB의 이득, 1.1 dB의 NF, 11.6 dB/10.4 dB의 입출력 반사 손실 특성을 보였다.

• 한국임상약학회지
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• 제26권3호
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• pp.201-206
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• 2016

Objective: Direct current cardioversion for atrial fibrillation could be associated with the risk of thromboembolic events. Anticoagulation therapy with warfarin (INR 2.0-3.0) is recommended 3 weeks before and 4 weeks after cardioversion to reduce the risk of thromboembolism. This study evaluated warfarin therapy in pharmacist-managed anticoagulant services (ACS). Methods: This retrospective study was performed in 106 patients with atrial fibrillation from 2012 to 2013. The primary efficacy endpoint was the composite of stroke, transient ischemic attack, myocardial infarction, and cardiovascular death. The primary safety measure was major bleeding. To evaluate the peri-procedural effects of warfarin treatment, we studied whether target INR was maintained, as well as the maintenance period of the therapeutic range. Quality of treatment was measured by time in therapeutic range (TTR) by using the Rosendaal method. Results: There were no thromboembolic events, but TEE examination at time of cardioversion showed a left atrial thrombus in three patients (2.8%). Bleeding complications after cardioversion occurred in 2 patients (1.9%). The average INR value at the time of cardioversion was $2.59{\pm}0.8$, and was within the therapeutic range in 83 patients (78%). Analysis of the patients in whom the value was within the therapeutic range twice consecutively showed that the ratio of TTR was 80% and the therapeutic range was maintained in 67 patients (63%) for an average of 4.90 weeks prior to cardioversion. Similarly, 76 patients (72%) had a stable INR within the therapeutic range for an average of 5.70 weeks and a mean TTR of 83%. Conclusion: Pharmacists significantly contributed to appropriate warfarin treatment with close monitoring during cardioversion. Likewise, active pharmacist monitoring and systemic management should be considered to reduce thromboembolism and bleeding complications in the peri-cardioversion period.