• Molecules and Cells
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• 제41권6호
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• pp.553-561
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• 2018

Icariside II (ICA II) is used in erectile dysfunction treatment. Adipose tissue-derived stem cells (ADSCs) are efficient at improving erectile function. This study aimed to explore the action mechanism of ADSCs in improving erectile function. ADSCs were isolated from the adipose tissues of rats. Cell proliferation was determined using the Cell Counting Kit-8 (CCK-8) assay. The expressions of mRNA and protein were determined separately through qRT-PCR and western blot. The endogenous expressions of related genes were regulated using recombinant plasmids and cell transfection. A Dual-Luciferase Reporter Assay was performed to determine the interaction between miR-34a and STAT3. Rat models with bilateral cavernous nerve injuries (BCNIs) were used to assess erectile function through the detection of mean arterial pressure (MAP) and intracavernosal pressure (ICP). ICA II promoted ADSCs' proliferation and differentiation to Schwann cells (SCs) through the inhibition of miR-34a. Suppressed miR-34a promoted the differentiation of ADSCs to SCs by upregulating STAT3. ICA II promoted the differentiation of ADSCs to SCs through the miR-34a/STAT3 pathway. The combination of ICA II and ADSCs preserved the erectile function of the BCNI model rats. ADSCs treated with ICA II markedly preserved the erectile function of the BCNI model rats, which was reversed through miR-34a overexpression. ICA II promotes the differentiation of ADSCs to SCs through the miR34a/STAT3 pathway, contributing to erectile function preservation after the occurrence of a cavernous nerve injury.

• 한국정보보호학회:학술대회논문집
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• 한국정보보호학회 2006년도 하계학술대회
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• pp.251-257
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• 2006

The performance of face recognition methods using subspace projection is directly related to the characteristics of their basis images, especially in the cases of local distortion or partial occlusion. In order for a subspace projection method to be robust to local distortion and partial occlusion, the basis images generated by the method should exhibit a part-based local representation. We propose an effective part-based local representation method named locally salient ICA (LS-ICA) method for face recognition that is robust to local distortion and partial occlusion. The LS-ICA method only employs locally salient information from important facial parts in order to maximize the benefit of applying the idea of 'recognition by parts.' It creates part-based local basis images by imposing additional localization constraint in the process of computing ICA architecture I basis images. We have contrasted the LS-ICA method with other part-based representations such as LNMF (Localized Non-negative Matrix Factorization)and LFA (Local Feature Analysis). Experimental results show that the LS-ICA method performs better than PCA, ICA architecture I, ICA architecture II, LFA, and LNMF methods, especially in the cases of partial occlusions and local distortion

• 한국정보과학회논문지:소프트웨어및응용
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• 제33권5호
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• pp.481-488
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• 2006

부공간 투영기술(subspace projection)을 이용한 얼굴인식기술의 성능은 이들 기저영상들(basis images)의 특징과 밀접한 관련이 있다. 특히 표정변화와 같은 국부적 왜곡이나 오클루전이 있는 경우의 인식성능은 기저영상들의 특징에 의해 영향을 받게 된다. 부공간 투영기반의 얼굴인식 방법이 오클루전이나 표정변화와 같은 국부적인 왜곡발생에 강인하려면 부분국부적 표현(part-based local representation)의 기저벡터를 갖는 것이 중요하다. 본 연구에서는 국부적 왜곡과 오클루전에 강인한 효과적인 부분국부적 표현방법을 제안한다. 제안한 방법을 LS-ICA(locally salient ICA) 방법이라고 명명하였다. LS-ICA방법은 ICA 구조I의 기저영상을 구하는 과정에서 공간적인 국부성(locality)의 제약조건을 부과함으로써 부분국부적 기저영상(part-based local basis images)을 얻는 방법이다. 결과적으로 공간적으로 현저한 특징만을 포함하는 기저영상을 사용하게 되며, 이는 "Recognition by Parts"의 방법론과 유사하다. LS-ICA방법과 LNMF(Localized Non-negative Matrix Factorization)와 LFA(Local Feature Analysis)와 같은 기존의 부분 표현방법(part-based representation)들에 대해 다양한 얼굴영상 데이타베이스를 사용하여 실험한 결과, LS-ICA방법이 기존의 방법에 비하여 높은 인식성능을 보였으며, 특히 오클루전이나 국부적인 변형이 포함된 얼굴영상에서 뛰어난 인식성능을 보였다.

• Journal of Korean Neurosurgical Society
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• 제40권1호
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• pp.16-21
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• 2006

Objective : Young neurosurgeons need to focus on the mortality and morbidity of aneurysmal neck clipping to develop a personal experience with an initial series. Methods : Total 88 aneurysms from 75 patients who underwent neck clipping by the same operator from 2001 to 2004 were reviewed. Patients were divided into three groups : first year [Group I], second year [Group II], and third year [Group III] in each group. Location of aneurysm, age, Fisher grade, Hunter-Hess grade [H-H grade], postoperative Glasgow outcome scale [GOS], and complications related to surgical procedures were evaluated with Chi-square and logistic regression analyses. Results : Fourteen patients had complications related to surgery [18.7%]. The major causes of mortality and morbidity related to surgery were cerebral infarction, hemorrhage and brain swelling due to intraoperative rupture, brain retraction and vasospasm. Among the 4 cases of mortality were 2 patients in Group I, 1 patient in Group II and 1 patient in Group III, and location of aneurysms were 2 internal carotid artery[ICA] and 2 posterior communicating artery[PCoA] aneurysms. There were 4 morbidity and new neurological deficits in Group I, 4 in Group II and 2 in Group III. Although mortality and morbidity during the learning curve had a statistical significance in H-H grade, age [>60 years old], and aneurysm location [especially ICA aneurysm] as variables, mortality mainly occurred in ICA and PCoA aneurysms. Conclusion : Experienced supervision or endovascular approach should be considered for the treatment of ICA and PCoA aneurysms during the learning curve.

• 전자공학회논문지SC
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• 제44권2호
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• pp.10-17
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• 2007

의료용 초음파 시스템으로 혈류 속도를 측정할 때, 순수한 혈류 신호의 검출이 필요하다. 초음파 트랜스듀서를 통해 들어오는 반사 신호는 체세포 조직(tissue), 혈관 벽(blood wall), 적혈구(red blood cell), 잡음(noise) 등이 혼합된 신호이다. 혼합된 신호에서 체세포 조직과 혈관 벽 신호를 클러터(clutter)라고 한다. 본 논문에서는 ICA(independent component analysis)를 적용하여 클러터 신호와 잡음을 효과적으로 제거하는 방법을 제시하였다. Field II 초음파 시뮬레이션 프로그램을 이용하여 초음파 반사 신호를 생성하고, ICA를 사용하여 각 독립 신호들을 분리, 클러터 신호를 제거하여 혈류 신호를 추출했다. 추출전 혈류신호를 2D 자기상관(autocorrelation) 방법으로 혈류 속도를 측정했다. 그리고 PCA(principal component analysis)방법을 적용한 고유 필터(autocorrelation) 방법으로 클러터를 제거한 결과와 비교하였다. 그 결과 잡음 환경에서의 혈류 속도 측정에 ICA 방법이 우수한 적용 결과를 보였다.

• Journal of Korean Neurosurgical Society
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• 제37권5호
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• pp.329-335
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• 2005

Objective: Acute spontaneous subdural hematoma(SDH) secondary to a ruptured intracranial aneurysm is a rare event. The authors present nine cases with aneurysmal SDH. Methods: We analyzed nine cases of aneurysmal SDH from 337 patients who underwent treatment for a ruptured aneurysm between January 1998 and May 2004. Clinical and radiological characteristics and postoperative course were evaluated by reviewing medical records, surgical charts and intraoperative videos. Results: The nine patients comprised four males and five females with a mean age of 53years (range 15-67years). The World Federation of Neurosurgical Societies grades on admission were I in one patient, II in two patients, III in five patients and V in one patient. With respect to location, there were four internal carotid-posterior communicating artery(ICA-Pcom) aneurysms, one distal anterior cerebral artery(DACA) aneurysm, one anterior communicating artery and three middle cerebral artery aneurysms. CT scans obtained from the four patients with ICA-Pcom aneurysms revealed SDH over the convexity and along the tentorium, and two of these patients presented with pure SDH without subarachnoid hemorrhage(SAH). In three patients with ICA-Pcom aneurysm, the ruptured aneurysm domes adhered to the petroclinoid fold. In the patient with the DACA aneurysm, the domes adhered tightiy to the pia mater and the falx. Conclusion: Ruptured intracranial aneurysm may cause SDH with or without SAH. In the absence of trauma, the possibility of aneurysmal SDH should be considered.

• Investigative Magnetic Resonance Imaging
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• 제8권1호
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• pp.17-23
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• 2004

목적 : 이차원 위상대조 자기공명영상을 이용하여 나이변화와 뇌실질 부피변화 및 혈관이상의 정도에 따른 총뇌혈류량의 변화를 알고자 하였다. 대상 및 방법 : 12명의 지원자를 포함한 73명을 대상으로 T2강조 영상과 Time-of-flight 방법의 자기공명혈관촬영과 이차원 위상대조 자기공명영상을 얻었다. 정상군은 지원자 12명과 자기공명영상 및 자기공명혈관촬영에서 정상소견을 보인 21명으로서 이들은 18-29세, 30-49세, 50-66세 군으로 나누었다. 비정상군은 T2강조영상의 뇌실질부피 변화정도와 자기공명 혈관촬영의 동맥경화 정도에 따라 mild reduction군(17명) , marked reduction군(12명)으로 나누었고, 뇌실질이 증가한 increased volume군(6명)과 Moya-moya군(5명)으로 분류하였다 뇌혈류는 위상대조 자기공명영상의 속도-혈류 곡선으로부터 양쪽 내경동맥과 추골동맥에서 측정하고 합하여 뇌의 총뇌혈류량으로 하였으며, 각군 사이의 혈류량을 비교 관찰하였다. 결과 정상군의 총뇌혈류량은 18-29세군은$12.0{\pm}2.1ml/sec$, 30-49세군은 $11.8{\pm}1.9m1/sec$, 50-66세군은 $10.9{\pm}2.2ml/sec$였다. 비정상군 중에서 mild reduction 군은 $9.5{\pm}2.5ml/sec$, marked reduction 군은 $7.6{\pm}2.0ml/sec$, increased volume군은 $7.3{\pm}1.2ml/sec$, Moya-moya군은 $7.0{\pm}1.1ml/sec$였다. 결론 : 총뇌혈류량은 나이 증가에 따라 감소하였고, 뇌실질부피 감소와 동맥경화 정도에 따라 감소하였으며 increased volume군과 Moya-moya군에서도 감소하였다. 이차원 위상대조 자기공명영상은 나이변화나 뇌실질의 부피변화와 혈관이상을 초래하는 다양한 뇌질환에서 총뇌혈류량을 관찰할 수 있는 유용한 방법이라고 생각된다.