• Tuberculosis and Respiratory Diseases
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• 제38권3호
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• pp.270-279
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• 1991

It has been well known that the integrity of airway epithelium is important in developing of bronchial hyperreactivity or bronchial asthma. But the mechanisms underlying this nonspecific airway hyperresponsiveness are not yet determined. To evaluate the ability of guinea pig trachea to release an epithelium derived relaxing factor (EpDRF) which relax rat vascular smooth muscle, we performed the coaxial bioassay using guinea pig trachea and rat aorta. And to evaluate the nature of EpDRF we investigate the influence of methylene blue and indomethacin on the coaxial bioassay. Results were as follows. 1) Vascular smooth muscle mounted into the epithelium intact trachea which was precontracted with phenylephrine was relaxed by addition of histamine or acetylcholine. But vascular smooth muscle mounted into epithelium denuded trachea failed to be relaxed. 2) Epithelium dependent relaxation of vascular smooth muscle was not affected by pretreatment of methylene blue or indomethacin. These results strongly suggests that guinea pig tracheal epithelium releases EpDRF which is able to relax rat vascular smooth muscle. And EpDRF released by airway epithelium is not related to endothelium derived relaxing factor (EDRF) or cyclooxygenase products.

• 한방재활의학과학회지
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• 제19권2호
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• pp.27-49
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• 2009

Objectives : The purpose of this study was to investigate the effects of Yanghyuljanggeungunbo-tang(Yangxuezhuangjinjianbu-tang) and Cervi Cornu Parvum pharmaco-acupuncture in Spinal Cord Injury(SCI)-induced rats. Methods : The subjects were divided into 5 groups ; Normal, Control no treatment after SCI, Experimental I taken with Yanghyuljanggeungunbo-tang (Yangxuezhuangjinjianbu-tang) 500 mg/kg $0.5m{\ell}$ daily after inducing SCI. Experimental II taken with Cervi Cornu Parvum pharmaco-acupuncture at Taegye(KI3) and $Yangnungch{\acute{o}}n$(GB34) after inducing SCI and Experimental III taken with Yanghyuljanggeungunbo-tang(Yangxuezhuangjinjianbu-tang) 500 mg/kg $0.5m{\ell}$ and Cervi Cornu Parvum pharmaco-acupuncture at KI3 and GB34 to SCI-induced rats. After each operation, the present author observed the motor behavior recovery and nerve regeneration by analysis of the motor behavior tests, EMG, hematological(AST, ALT, WBC), histological and immunological changes. Rats were tested at modified Tarlov test at the 1st, 2nd, 3rd, 4th day, and Motor behavior test at 1st, 3rd, 7th, 14th, 21st day. Results : Results are as follows. 1. All the experimental groups were improved compared with control group in the motor behavior tests including Tarlov test, Basso-Beattle-Bresnahan locomotor rating scale, modified inclined plane test, open field test, grid walk test and narrow beam test. Especially Experimental III was improved significantly among other groups. 2. In EMG test, H wave appeared weak only in Experimental III. And M wave was increased significantly in Experimental III. 3. All the experimental groups were significantly decreased compared with control group in serum AST, serum ALT and serum WBC tests. 4. significantly decreased in Tumor Necrosis Factor-${\alpha}$ test compared with the first day of SCI. 5. Muscle contraction and denaturation of all the experimental groups were inhibited in histological observations of gastrocnemius muscle. Especially, those of experimental III was more effective. 6. NGF and BDNF of spinal cord gray matter in all the experimental groups were increased compared with control group. Especially, those of experimental III was more effective. Conclusions : As above, it can be suggested that Yanghyuljanggeungunbo-tang(Yangxuezhuangjinjianbu-tang) and Cervi Cornu Parvum pharmaco-acupuncture may improve motor behavior, EMG, hematological, histological and immunological findings in Spinal Cord Injury(SCI)-induced rats. Especially, effects will be somewhat better in combination of these two treatments.

• 한국산학기술학회논문지
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• 제11권11호
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• pp.4635-4642
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• 2010

라텍스로 개질된 콘크리트는 높은 휨강도 뿐만아니라 부착강도 및 투수저항성이 좋은 재료특성을 제공한다. 이러한 이점을 활용한 초속경 라텍스개질 콘크리트(VES-LMC)에 관련된 연구결과는 재료에 관한 것이 대부분으로, VES-LMC로 덧씌우기 보강된 RC 보의 부착 경계면 거동특성에 대한 체계적인 연구는 미진하다. 따라서 본 논문에서는 VES-LMC로 보강된 철근콘크리트 보의 비선형 휨 거동에 대한 특성을 알아보고자 ABAQUS를 매개변수 연구를 수행한 결과 다음과 같은 결과를 얻을 수 있었다. 비선형 휨 해석을 위하여 본 논문에 적용된 모델의 적합성 여부를 확인한 결과 실험값과 비교적 유사한 경향을 보이는 것을 확인 할 수 있었다. 두께가 증가함에 따라 최대 저항강도가 증가하는 경향을 보여주었으며, 또한 강성 이 증가하여 내하력이 증진되는 결과를 확인할 수 있었다. 부착강도를 변수로 해석한 결과, 전단강도가 증가함에 따라 휨 저항능력이 향상되는 결과를 확인 하였으며, 두 이질재료의 부착능력이 구조물의 내하력에 지배적인 인자로 작용하는 것을 알 수 있었다.

• Journal of Chest Surgery
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• 제37권3호
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• pp.210-219
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• 2004

외부 자극에 의하여 세포 내 $Ca^2$$^{+}$이 증가하면 세포 내 $K^{+}$이 유출되어 세포 외 $K^{+}$ 농도는 수 mM 범위에서 증가할 수 있다. 이러한 세포 외 $K^{+}$의 증가가 혈관 수축성에 미치는 영향을 규명하고자, 세포 외 $K^{+}$가 혈관평활근 수축성, 내피세포 의존성 이완과 혈관내피세포 $Ca^2$$^{+}$ 농도에 미치는 영향을 알아보고자 하였다. 토끼에서 분리한 경동맥, 상장간막동맥 분지, 기저동맥과 쥐의 대동맥에서 등장성 수축을 기록하였으며 배양한 쥐의 대동맥 혈관내피세포와 인간 제대정맥 내피세포에서 세포 내 $Ca^2$$^{+}$ 변화를 측정하였다. 세포 외 $K^{+}$ 농도를 6에서 12 mM로 증가하는 경우 도관동맥인 토끼 경동맥은 수축성에 변화가 없는 반면 저항혈관인 기저동맥과 상장간막동맥분지는 이완하였다. 이러한 $K^{+}$ 유발 이완은 혈관 종류에 따라 차이가 있었는데 기저동맥에서는 세포 외 $K^{+}$ 농도를 6에서 12 mM로 증가하였을 때보다 세포 외 $K^{+}$ 농도를 1에서 3 mM로 증가하였을 때 더 크게 이완하였으며 상장간막동맥의 분지에서는 반대로 세포 외 $K^{+}$ 농도를 6에서 12 mM로 증가하였을 때 더 크게 이완하였다. 그리고 세포 외 $K^{+}$ 농도를 6에서 12 mM로 증가하였을 때의 이완은 $Ba^2$$^{+}$에 의하여 억제되는 반면 1에서 3 mM로 증가에 의한 이완은 억제되지 않았다. 쥐 대동맥에서도 토끼 경동맥과 동일한 효과가 관찰되었는데 세포 외 $K^{+}$ 농도를 6 mM에서 12 mM로 변화시켜도 norepinephrine혹은 prostaglandin $F_2$$_{\alpha}$에 의한 수축력은 유의한 변화가 없었다. 또한 세포 외 $K^{+}$ 농도를 점차 증가시키는 경우 12 mM 이상 증가가 되면 혈관평활근이 수축하기 시작하였지만 12 mM 이하의 증가에 의해서는 혈관평활근의 수축력은 증가하지 않았다. 한편 쥐 대동맥에서 acetylcholine에 의하여 유발된 내피세포 의존성 이완은 세포 외 $K^{+}$ 농도를 정상 6 mM에서 12 mM로 증가시키면 억제되었다. 한편 배양한 쥐 대동맥 내피세포에서는 acetylcholine 혹은 ATP에 의하여 세포 내 $Ca^2$$^{+}$이 증가하였다. 증가한 세포 내 $Ca^2$$^{+}$은 세포 외 $K^{+}$농도를 6 mM에서 12 mM로 증가시키면 가역적 및 농도 의존적으로 감소하였다. 세포 외 $K^{+}$ 증가에 의한 세포 내 $Ca^2$$^{+}$ 억제 효과는 인간 제대정맥 내피세포에서도 관찰되었다. 그리고 세포 외 $K^{+}$ 증가에 의한 내피세포 의존성 이완의 억제효과는 $Na^{+}$- $K^{+}$ pump 억제제인 ouabain과 $Na^{+}$-C $a^2$$^{+}$exchanger 억제제인 N $i^2$$^{+}$에 의하여 억제되었다. 이러한 실험 결과로 미루어 세포 외 $K^+$의 증가는 저항혈관 평활근을 이완시키는데 그 기전은 혈관 종류에 따라 차이가 있었다. 그리고 세포 외 $K^{+}$의 증가는 혈관내피세포 $Ca^2$$^{+}$을 감소시켜 내피세포 의존성 이완을 억제하는데 이는 $Na^2$$^{+}$- $K^2$$^{+}$pump를 활성화시켜 일어나는 것으로 생각된다.

• 한국가구학회지
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• 제21권6호
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• pp.459-468
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• 2010

가구를 디자인하는데 있어서 재료는 매우 중요한 요소이다. 목재는 가구 재료 가운데 가장 많은 부분을 차지하고 있다. 목재는 자연 재료로 부드럽고 환경 친화적인 반면에 수축과 팽창 같은 변화가 심해 목재가 지닌 특성을 고려하지 않으면 올바른 디자인을 할 수가 없다. 목재를 다루는 기술 가운데 휨 가공법은 가구의 다양한 형태를 만들어내는데 매우 유용한 기술 가운데 하나이며, 오래 전부터 가구제작에 사용되어 오면서 증기, 암모니아, 고주파 등 가공방법에 관한 기술적 발전을 가져왔다. 목재는 점탄성 물질로 약간의 가소성을 가지고 있어 힘을 가하면 아름다운 곡선을 만들 수 있는 재료적 특성을 가지고 있다. 따라서 이 논문은 지금까지 가구제작에 사용되어 온 휨 가공법의 종류와 그 특성들을 조사하여 대량생산 또는 소량생산에 적합한 방법들을 체계적으로 분류하여 가구의 형태와 생산방식에 따라 어떠한 가공법을 사용하여야 되는지를 연구하고자 한다. 이번 연구를 통해서 휨 가공방법의 장점은 가구디자인에서 디자이너의 다양한 아이디어를 표현할 수 있는 기술적 방법의 한 가지라 할 수 있다. 분석결과 증자처리 휨 가공은 다품종 소량생산에 적합하고, 암모니아 휨 가공은 스프링 백 현상이 없으며 다양한 자유곡선의 형태 가공에 적합한 방법이라 할 수 있다. 대량생산에서는 고주파 가공이 많이 사용되며, 거단 휨 가공은 작업방법이 용이했고, 적층 휨 가공은 가장 일반적인 가공법으로 소량 또는 대량생산에 모두 적합한 가공법이라 할 수 있다. 또한 이 연구를 통해 많은 가구 디자이너와 제작자들이 목재의 휨 가공에 도움을 주는데 목적이 있다.

• Journal of Chest Surgery
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• 제51권4호
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• pp.266-272
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• 2018

Background: Limited comparative data are available on the efficacy of cryoablation versus radiofrequency ablation in patients with atrial fibrillation. This study aimed to compare radiofrequency ablation and cryoablation with regard to clinical outcomes and the restoration of sinus rhythm or atrial contractility. Methods: A total of 239 patients who underwent surgical ablation between August 2003 and December 2016 at our institution were included. The patients were divided into 2 groups according to the energy device that was used (group A: n=140, radiofrequency ablator; group B: n=99, cryoablator). Echocardiographic data, overall survival, and major cardiovascular and cerebrovascular event (MACCE)-free survival were compared between the 2 groups. Results: At 1 year of follow-up, the atrial contractility recovery rate was 32.2% (19 of 59) in group A and 48.8% (21 of 44) in group B. In addition, cryoablation was found to be a predictive factor for the recovery of atrial contractility (cryoablation vs. radiofrequency ablation: odds ratio, 2.540; 95% confidence interval, 1.063-6.071; p=0.036). The left ventricular ejection fraction was significantly higher in group B ($53.1%{\pm}11.5%$ vs. $59.1%{\pm}6.3%$, p=0.001). The median follow-up duration was 36 months. The 5-year overall survival rate was $80.1%{\pm}3.6%$ in group A and $92.1%{\pm}2.9%$ in group B (p=0.400). The 5-year MACCE-free survival rate was $70.3%{\pm}4.0%$ in group A and $70.9%{\pm}5.6%$ in group B (p=0.818). Conclusion: Cryoablation was associated with a higher atrial contractility restoration rate and better left ventricular function than radiofrequency ablation. However, no significant relationship was observed between the energy source and overall or MACCE-free survival.

• 한국전문물리치료학회지
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• 제15권2호
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• pp.54-63
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• 2008

The purpose of this study was to examine the effect of the hip internal rotation on knee extensor and hip abductor electromyographic (EMG) activity during stair up and stair down mobility. Eighteen healthy subjects were recruited. All subjects performed stair up and down movements on a step of 30cm height while maintaining the hip in neutral (condition 1) and hip in internal rotation (condition 2). Surface EMG activity was recorded from five muscles (gluteus maximus, vastus lateralis (VL), vastus medialis oblique (VMO), posterior gluteus medius (Gmed), and tensor fascia latae (TFU)) and hip internal rotation angle was measured using a three dimensional motion analysis system The time period for stair up and down was normalized using the MatLab 6.5 program, and EMG activity was normalized to the value of maximal voluntary isometric contraction (%MVIC). The EMG activities according to the hip rotation (neutral or internal rotation) during the entire time period of stair up and down in each phase were compared using a paired t-test. During the entire period of stair up, the EMG activities of VL and TFL in condition 2 were significantly greater than in condition 1 (p<.05). During the entire period of stair down, the EMG activities of VL and TFL in condition 2 were significantly greater than in condition 1 (p<.05). However, the EMG activities of the other muscles were not significantly different between the conditions (p>.05). These results suggest that the stair up and down maintaining hip internal rotation was could be a contributing factor on patellar lateral tracking.

• 한국임상수의학회지
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• 제27권3호
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• pp.262-267
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• 2010

마그네슘($Mg^{2+}$)은 325 개 이상의 생리적 및 생화학적 과정에 필수적인 조효소이며 신경활성, 심장근 감수성, 신경근 전달, 근수축, 혈관운동 긴장과 혈압 등의 신체활동과 관련된 일련의 과정에서 중요한 역할은 한다. 하지만 신체활동과 관련된 혈액 이온화 $Mg^{2+}$ ($iMg^{2+}$)에 관한 보고는 거의 없을 뿐만 아니라 혈액 총 $Mg^{2+}$을 측정한 연구결과들은 논란의 여지가 있다. 대사적 요구가 증가하는 단기간의 고강도 운동에서 혈액 $iMg^{2+}$의 변화를 측정하였다. 고강도의 수영운동 후에 혈액 산도, 혈당, 중탄산염, 산소 및 칼슘은 감소한 반면, 젖산, 이산화탄소, $iMg^{2+}$, 나트륨, 칼륨은 유효한 증가를 보였다. 고강도 수영에서 혈액 $iMg^{2+}$의 변화는 혈액 산도, 혈당, 중탄산염과 칼슘의 변화와는 역관계의 상관을 보인 반면, 젖산과 음이온차와는 정관계의 유의한 상관을 보였다. 이 결과는 단기간 고강도의 수영운동이 고마그네슘혈증을 야기할 수 있고 이는 대사성 및 호흡성 산증에 의한 근육내 $iMg^{2+}$의 증가에 수반하는 근육에서의 $iMg^{2+}$ 유출의 증가에 의한 것으로 판단된다.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2009년도 학술논문요약집
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• pp.187-187
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• 2009

Opening of fractures induced by shear dilation or normal deformation can be a significant source of fracture permeability change in fractured rock, which is important for the performance assessment of geological repositories for spent nuclear fuel. As the repository generates heat and later cools the fluid-carrying ability of the rocks becomes a dynamic variable during the lifespan of the repository. Heating causes expansion of the rock close to the repository and, at the same time, contraction close to the surface. During the cooling phase of the repository, the opposite takes place. Heating and cooling together with the, virgin stress can induce shear dilation of fractures and deformation zones and change the flow field around the repository. The objectives of this work are to examine the contribution of thermal stress to the shear slip of fracture in mid- and far-field around a KBS-3 type of repository and to investigate the effect of evolution of stress on the rock mass permeability. In the first part of this study, zones of fracture shear slip were examined by conducting a three-dimensional, thermo-mechanical analysis of a spent fuel repository model in the size of 2 km $\times$ 2 km $\times$ 800 m. Stress evolutions of importance for fracture shear slip are: (1) comparatively high horizontal compressive thermal stress at the repository level, (2) generation of vertical tensile thermal stress right above the repository, (3) horizontal tensile stress near the surface, which can induce tensile failure, and generation of shear stresses at the comers of the repository. In the second part of the study, fracture data from Forsmark, Sweden is used to establish fracture network models (DFN). Stress paths obtained from the thermo-mechanical analysis were used as boundary conditions in DFN-DEM (Discrete Element Method) analysis of six DFN models at the repository level. Increases of permeability up to a factor of four were observed during thermal loading history and shear dilation of fractures was not recovered after cooling of the repository. An understanding of the stress path and potential areas of slip induced shear dilation and related permeability changes during the lifetime of a repository for spent nuclear fuel is of utmost importance for analysing long-term safety. The result of this study will assist in identifying critical areas around a repository where fracture shear slip is likely to develop. The presentation also includes a brief introduction to the ongoing site investigation on two candidate sites for geological repository in Sweden.

• 한방재활의학과학회지
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• 제19권2호
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• pp.1-25
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• 2009

Objectives : The purpose of this study was to investigate the effects of Yanghyuljanggeungunbo-tang(Yangxuezhuangjinjianbu-tang, YGKT) and electrical acupuncture treatment in spinal cord injury(SCI)-induced rats. Methods : The subjects were divided into 5 groups ; Normal, Control-no treatment after SCI, Experimental I(Exp. I)-taken with YGKT 500 mg/kg $0.5m{\ell}$ daily after SCI. Experimental II(Exp. II)-taken with electrical acupuncture after SCI and Experimental III(Exp. III)-taken with YGKT 500 mg/kg $0.5m{\ell}$ and electrical acupuncture after SCI. After each operation, the present author observed cytological changes, the motor behavior recovery and nerve regeneration by analysis of the motor behavior tests, EMG, hematological(AST, ALT, WBC), histological and immunological changes. Rats were tested by Motor behavior test at 1st, 3rd, 7th, 14th and 21st day. Results : 1. All the experimental groups were improved compared with control group in the motor behavior tests including Tarlov test, Basso-Beattle-Bresnahan locomotor rating scale, modified inclined plane test, open field test, grid walk test and narrow beam test. Especially Exp. III was significantly improved among other groups. 2. In EMG test, H and M wave were significantly increased in Exp. III. 3. All the experimental groups were significantly decreased compared with control group in AST, ALT and WBC. 4. NGF, BDNF and Trk B of spinal cord gray matter in all the experimental groups were increased compared with control group. Especially, Exp. III was more effective. 5. In histological observations, muscle contraction and denaturation of gastrocnemius muscle of all the experimental groups were inhibited. Especially, those of Exp. III was more effective. On the observations of liver and kidney, cell atrophy and apoptosis of all the experimental groups were decreased compared with control group. Especially, those of Exp. III was more effective. Conclusions : It can be suggested that YGKT and electrical acupuncture may improve motor behavior, EMG, hematological, histological and immunological findings in SCI-induced rats. Especially, combination of these two treatments will be somewhat better in spinal nerve recovery and motor function improvement.