• 제목/요약/키워드: A. cortex

검색결과 1,964건 처리시간 0.031초

Stress Analysis of Femoral Stems on Non-Cemented Total Hip Replacement - A Three-Dimensional Finite Element Analysis -

  • Kim, Sung-Kon;Chae, Soo-Won;Jeong, Jung-Hwan
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1997년도 추계학술대회
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    • pp.263-266
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    • 1997
  • Three dimensional numerical model based on the finite element method(FEM) were developed to predict the mechanical behavior of hip implants. The purpose of this study is to investigate the stress distribution of two types of cementless total hip replacement femoral component -a straight stem and a curved stem, and to compare their effect on the stress shielding between two types by three dimensional finite element method. The authors analyzed von Mises stress in the cortex & stem and compared the stress between the straight and the curved stem. In comparison of stresses between two different design of femoral stem, there was 25% more decrease of stress in straight stem than curved stem in the medial cortex at proximal region. The straight stem had consistently much lower stresses than the curved stem throughout the whole medial cortex with maximum 70% reduction of stress. However, there was little change in stress between nature and 2 implanted femur throughout the lateral cortex. Stress of femoral stem was much higher in the straight stem than the curved stem up to 60%. The straight stem had more chance of stress shielding and a risk of fatigue fracture of the stem compared with the curved stem in noncement hip arthroplasty. In design of femoral stem still we have to consider to develop design to distribute more even stress on the proximal medial cortex.

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A Subthreshold PMOS Analog Cortex Decoder for the (8, 4, 4) Hamming Code

  • Perez-Chamorro, Jorge;Lahuec, Cyril;Seguin, Fabrice;Le Mestre, Gerald;Jezequel, Michel
    • ETRI Journal
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    • 제31권5호
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    • pp.585-592
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    • 2009
  • This paper presents a method for decoding high minimal distance ($d_{min}$) short codes, termed Cortex codes. These codes are systematic block codes of rate 1/2 and can have higher$d_{min}$ than turbo codes. Despite this characteristic, these codes have been impossible to decode with good performance because, to reach high $d_{min}$, several encoding stages are connected through interleavers. This generates a large number of hidden variables and increases the complexity of the scheduling and initialization. However, the structure of the encoder is well suited for analog decoding. A proof-of-concept Cortex decoder for the (8, 4, 4) Hamming code is implemented in subthreshold 0.25-${\mu}m$ CMOS. It outperforms an equivalent LDPC-like decoder by 1 dB at BER=$10^{-5}$ and is 44 percent smaller and consumes 28 percent less energy per decoded bit.

ARM Cortex-A15 프로세서를 위한 RTOS 포팅 구현 (Implementation of Porting RTOS to ARM Cortex-A15)

  • 심철;최민
    • 한국컴퓨터정보학회:학술대회논문집
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    • 한국컴퓨터정보학회 2017년도 제55차 동계학술대회논문집 25권1호
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    • pp.3-4
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    • 2017
  • 본 논문에서는 가상화 기술을 지원하는 ARMv7 Cortex-A15 프로세서가 탑재된 임베디드 보드를 위한 실시간 운영체제(RTOS) 구현을 위한 방법을 제안한다. ARM Cortex-A15 프로세서가 지원하는 Generic Interrupt Controller와 Generic Timer에 대해 알아보고, 가상화 시스템에서 인터럽트 오버헤드를 줄이는 GICv2와 가상 타이머인 Generic Timer를 사용하여 실시간 운영체제인 FreeRTOS를 임베디드 보드에 이식하였다.

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시호(柴胡)와 지골피(地骨皮) 합제(合劑)가 강제수영부하실험에서 HPA Axis와 카테콜라민 시스템에 미치는 영향 (Effects of Mixture of Bupleuri Radix and Lycii Radicis Cortex on the Change of HPA-Axis and Catecholamic System in the Forced Swimming Test)

  • 조은호;이태희
    • 대한한의학방제학회지
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    • 제19권1호
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    • pp.161-174
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    • 2011
  • Objectives : The effects of Extraction after Mixture of Bupleuri Radix and Lycii Radicis Cortex on the change of the HPA-Axis system and the Catecholamic system was investigated. Methods : After performing the Forced Swimming Test(FST), the expressions of corticotropin releasing factor(CRF), c-Fos in the paraventricular nucleus(PVN), and tyrosine hydroxylase(TH) in the ventral tegmental area(VTA) and locus coeruleus(LC) were measured by immunohistochemical method. Results : The duration of immobility in FST was significantly decreased in A 100(Extraction after Mixture of Bupleuri Radix and Lycii Radicis Cortex, 100mg/kg) and A 400(Extraction after Mixture of Bupleuri Radix and Lycii Radicis Cortex, 400mg/kg)(p<0.001). The expression of CRF in the PVN was shown the tendency to reduce in A100 and A400. The expression of c-Fos in the PVN was shown the tendency to reduce in A100 and A400. The expression of TH in the VTA was shown the tendency to reduce mildly in A100 and A400. The expression of TH in the LC was significantly reduced in A400(p<0.001). And the dose dependent reduction tendency was shown, respectively. Conclusions : According to the results above mentioned, the immobility, c-Fos and CRF expression was reduced at lower dose and was increased at higher dose. Therefore there is contradictory effects on the HPA Axis system in accordance with the dose. But in the effects on the catecholaminergic system, it significantly reduced the expression of TH in the LC. It was validated that the effect on the catecholaminergic system was ruled by Bupleuri Radix rather than Lycii Radicis Cortex via mainly the noradernergic system.

수술중 체성감각 유발전위 및 대뇌피질 자극을 이용한 일차 운동피질영역과 일차 감각피질영역의 확인 - 증례보고 - (Identification of M-1, S-1 Cortex Using Combined Intraoperative SEP and Cortical Stimulation - A Case Report -)

  • 이제언;손병철;김문찬;강준기
    • Journal of Korean Neurosurgical Society
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    • 제29권7호
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    • pp.954-958
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    • 2000
  • In the removal of small subcortical lesion in the eloquent area like sensory-motor cortex, the prevention of neurologic deficit is important. We present our technique of identification of M-1, S-1 cortex in a case of subcortical granuloma located in sensorymotor cortex. To accurately localize mass, stereotactic craniotomy was planned. At the beginning of procedure, functional MRI of motor cortex was done with stereotactic headframe in place. Next, the stereotactic craniotomy about 4 cm was done under propofol anesthesia for cortical mapping. After reflection of dura, central sulcus was identified with phase-reversal response of intraoperative SEP(somatosensory evoked potential) of contralateral median nerve. Then the patient was awakened, and direct cortical stimulation was done. We observed the muscle contractions of elbow, hand and fingers and the paresthesia over forearm, hand, fingers on the M-1 and S-1 cortex. Through cortical mapping and stereotactic guidance, we concluded that the mass lie immediately posterior to central sulcus, then the mass was carefully removed through small transsulcal approach, opening about 1 cm of rolandic sulcus.

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Effect of Fluoxetine on the Induction of Long-term Potentiation in Rat Frontal Cortex

  • Kim, Hwang-Soo;Kim, Hyun-Sok;Hahn, Sang-June;Kim, Myung-Jun;Yoon, Shin Hee;Jo, Yang-Hyeok;Kim, Myung-Suk;Rhie, Duck-Joo
    • The Korean Journal of Physiology and Pharmacology
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    • 제8권6호
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    • pp.295-300
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    • 2004
  • Serotonin (5-hydroxytroptamine, 5-HT) has been shown to affect the induction of long-term potentiation (LTP) in the cortex such as the hippocampus, the visual cortex and the prefrontal cortex. Fluoxetine, as a selective serotonin reuptake inhibitor, is used in the management of a wide variety of psychological diseases. To study the effect of fluoxetine on the induction of LTP, we recorded the field potential in layer II/III of the frontal cortex from 3-wk-old. LTP was induced in horizontal input by theta burst stimulation (TBS). TBS with two-folds intensity of the test stimulation induced LTP, which was blocked by application of D-AP5 $(50 {\mu}M)$, an NMDA receptor antagonist. Whereas bath application of 5-HT $(10 {\mu}M)$ inhibited the induction of LTP, treatment with the 5-HT depleting agent, para-chloroamphetamine $(PCA,\;10{\mu}M)$, for 2hr did not affect the induction of LTP. Bath application of fluoxetine (1, 3, and $10 {\mu}M)$ suppressed the induction of LTP in concentration-dependent manner, however, fluoxetine did not inhibit the induction of LTP in 5-HT-depleted slices. These results indicate that fluoxetine may inhibit the induction of LTP by modulating serotonergic mechanism in the rat frontal cortex.

B 임파구(淋巴球)와 비만세포(肥滿細胞)에서 모단피(牡丹皮) 추출물(抽出物)의 항(抗)알러지 작용(作用)에 관(關)한 연구(硏究) (The effects of the abstracts from Moutan Cortex on an anti-allergic action on B cells and mast cells of the BALB/C mouse)

  • 진속창;이한배;김성균;이승희;서영배;이용구;이영철;장성익
    • 대한한방내과학회지
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    • 제24권1호
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    • pp.33-43
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    • 2003
  • Objective : This study was carried out for the purpose of proving the effect of anti-allergic efficacy on B cells and the mast cells of the BALB/C mouse by the abstraction from a Moutan cortex. Methods & Results : In order to know what the effect of an abstraction from Moutan cortex and about the expression of CD23 and IgE, IC-2 cell (mouse mast precursor cells that was dependent on IL-3), it was necessary to be activated. We then analyzed it from the flow of cytometry on the increase and the divorce of the B cells activated by anti-CD40. In order to know what the effect of it was on the organization of cytokine gene expression from the increase and divorce of the B cells and allergic acting by Moutan cortex, we found it necessary to examine the IC-2 cells and B cells. At the same time, as we examined the histamine release of IC-2 cells by ELISA method, we also examined the effect of Moutan cortex on the increase and divorce of the B cells by 3H-thymidine uptake method. We then analyzed the release of IL-4, IgE and histamine. Conclusions : As a results, Moutan Cortex promoted blood supply by extending the blood vessel of nasal mucous, which was contracted by the hypertrophied nasal mucous.

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일차 운동피질 경색후 발생한 국소성 간대성 근경련 1례 (A Case of Focal Myoclonus in Primary Motor Cortex Infarction)

  • 김민정;유봉구;김광수
    • Annals of Clinical Neurophysiology
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    • 제7권1호
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    • pp.20-21
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    • 2005
  • Myoclonus may originate from the cerebral cortex, subcortical structures, brainstem, spinal cord or peripheral nerve. But unilateral upper limb myoclonus related to cortical infarct is an unusual clinical picture. We report a 67-year-old man presented with myoclonus, associated with primary motor cortex infarction.

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전침자극이 Spontaneously Hypertensive Rat의 대뇌겉질, 뇌줄기, 소뇌 부위의 Nitric Oxide Synthase 신경세포에 미치는 영향 (Difference in NOS between 2 Hz and 100 Hz EA in cerebral cortex, brain stem and cerebellum of spontaneously hypertensive rats)

  • 김종인;김용석;김창환
    • Journal of Acupuncture Research
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    • 제18권4호
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    • pp.116-124
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    • 2001
  • Background and Objetive : The aim of this study was to investigate the effect of various electroacupuncture stimulation on NADPH-diaphorase in cerebral cortex, brain stem, cerebellum of spontaneously hypertensive rats. Materials and Methods : We evaluated the changes of NADPH-d-positive neurons using a histochemical method. The staining intensity of NADPH-d-positive neurons was assessed in a quantitative fashion using a microdensitometrical method based on optical density by means of an image analyzer. Results and Conculsion : The average optical density of NADPH-d-positive neurons of 100 Hz (bipolar square wave 0.2 ms duration and 100 Hz frequency) electroacupuncture treatment group significantly increased in most cortical areas comparison between the manual acupuncture and 2 Hz (bipolar square wave 0.2 ms duration and 2 Hz frequency) electroacupuncture groups. In the brain stem, the optical density of NADPH-d-positive neuron at only superficial gray layer of the superior colliculus area was same as cerebral cortex. We conclude that the morphological evidence for NADPH-d-positive neurons may be have regional change in cerebral cortex brain stem and cerebellum according to various electroacupuncture stimulations.

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생약복합제 GCSB-5의 품질 표준화를 위한 흑두 및 두충의 함량 분석 (Quantitative Analysis of Glycine Semen Nigra and Eucommiae Cortex for Standardization of GCSB-5 Preparation)

  • 이은희;차배천
    • 생약학회지
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    • 제40권1호
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    • pp.18-24
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    • 2009
  • GCSB-5 preparation is a purified extract from a mixture six herbal medicines (Acanthopanacis Cortex, Achyranthis Radix, Saposhnikoviae Radix, Cibotii Rhizoma, Glycine Semen Nigra, Eucommiae Cortex) that have been widely used in traditional medicine to treat various bone disorders. This study was carried out to obtain the HPLC analysis method that can be used to establish quantitative analysis of Glycine Semen Nigra and Eucommiae Cortex for standardization of GCSB-5 preparation. HPLC analysis methods for the simultaneous determination of genistin (Glycine Semen Nigra) and geniposide (Eucommiae Cortex) were established for the quality control of herbal medicinal raw material and preparation. And validation of HPLC analysis methods were conformed for verification of HPLC methods by check to specificity, linearity, intra-day precision, inter-day precision and accuracy following ICH guideline. As the result of quantitative analysis, the contents of genistin and geniposide in the raw material of GCSB-5 preparation were 0.0426-0.0427 mg/g and 0.431-0.432 mg/g. And GCSB-5 preparation contained genistin of 0.0202-0.0203 mg/capsule and geniposide of 0.211-0.212 mg/capsule, respectively.