• Title/Summary/Keyword: TCD

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Fabrication of Electrospun Juniperus Chinensis Extracts loaded PVA Nanofibers (향나무 추출물을 함유하는 PVA 나노섬유 제조)

  • Kim, Jeong-Hwa;Lee, Jung-Soon
    • Science of Emotion and Sensibility
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    • v.19 no.2
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    • pp.35-42
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    • 2016
  • Electrospinning is a simple and effective process for producing nanofiber with diameter range from nanometers to micrometers which have high specific surface area. Hence, medicated nanofibers can be readily fabricated using a solution containing a mixture of a plant-extracts and a polymer. It has proved that Juniperus Chinensis can be effectively used for the prevention of UV and SLS-induced advers skin reaction such as radical production, inflammation and skin cell damage. It also found that Juniperus Chinensis has efficient ingredient of antifungal activity and house dust mite repellent effect. The fabrication of PVA nanofibers containing Juniperus Chinensis extracts by electrospinning has been studied. PVA/Juniperus Chinensis extracts composite nanofibers were produced at different Juniperus Chinensis concentrations (0.25, 0.5, 1.5 wt. %). The parameters of electrospinning including polymer contents, voltage and tip-to-collector distance (TCD) were optimized for fabrication process. The study show that 12 wt. % PVA, 10kV applied voltage and TCD 10~20 cm are the best condition to obtain uniform PVA/Juniperus Chinensis extracts composite nanofibers. Morphologies of the electrospun composite nanofiber were observed by using a field emission scanning electron microscope. It has been found that the average diameters of fibers increased by the adding of Juniperus Chinensis extracts. As the results, PVA/Juniperus Chinensis extracts composite nanofibers having a diameter in the range from 310~360 nm were successfully prepared via an electrospinning.

Comparison of Cerebral Blood Flow between Patients with Metabolic Syndrome and Normal Group to Evaluate Diagnostic Value of Transcranial Doppler Ultrasound (대사증후군 환자군과 정상군의 뇌혈류 측정 비교를 통한 뇌졸중 위험인자에 대한 TCD의 진단적 가치 고찰)

  • Um, Eun-Jin;Park, Woo-Rham;Kim, Ju-Sung;Lee, Beom-Joon;Na, Byung-Jo
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.14 no.2
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    • pp.85-100
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    • 2010
  • Objectives: The purpose of this study was to evaluate diagnostic value of Transcranial Doppler Ultrasound about risk factor of stroke by comparing blood flow between patients with metabolic syndrome(MS group) and Normal group. Methods: 62 metabolic syndrome patients and 106 healthy adults were selected who had no cerebrovascular diseases, cardiovascular diseases and other systemic diseases. We measured the mean velocity(Vm), peak systolic velocity(Vs) and pulsatility index(PI) of MCA, ACA, PCA, VA, ICA in two groups using TCD. All subjects were divided by gender and age. Results: In comparing Ms group with normal group, Vm in the MCA, ACA, PCA, ICA and Vs in the MCA, ICA were lower in MS group. In all vessels, PI of MS group were higher than that of Normal group. In all vessels, Vm and Vs revealed negative correlation with age and PI revealed positive correlation with age. In 20-39 year olds, there was decrease in the Vs and Vm and increase of PI of MS group in comparison with normal group. There was significant difference in the Vm of PCA, ICA, Vs of MCA, PCA, ICA and PI of MCA, ACA. In 40-59 year olds, Vm in the MCA, ACA, ICA and Vs in the MCA, ACA were lower in MS group. PI in the MCA, ACA, PCA, ICA were higher in MS group. In 60-79 year olds, Vm of MCA, PCA, ICA was decreased in MS group than Normal group with no statistical signification. Vs in the MCA was lower and PI in the PCA was higher in MS group. In male, Vm of PCA and Vs of MCA were lower and PI of MCA, ACA, PCA, ICA were higher in MS group. In female, Vm of MCA, PCA, ICA and Vs of MCA, ICA were lower and PI of ACA, PCA, VA, ICA were higher in MS group. Conclusions: The significant difference in Vm, Vs, PI between MS group and normal group suggests hemodynamic disorder. Screening and prognosing high risk group can be done through TCD and this can be used to prevent stroke. More detailed study will be needed.

Effects of Sahyangsohap-won on Cerebral Hemodynamics in Healthy Subjects (사향소합원(麝香蘇合元)이 정상인의 뇌혈류역학에 미치는 영향)

  • Koo, Bon-Soo;Kim, Sung-Hwan;Moon, Sang-Kwan;Cho, Ki-Ho;Kim, Young-Suk;Bae, Hyung-Sup;Lee, Kyung-Sup;Ryu, Soon-Hyun
    • The Journal of Internal Korean Medicine
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    • v.22 no.2
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    • pp.199-205
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    • 2001
  • Background and Purpose : Transcranial doppler ultrasonography(TCD) is a noninvasive and nonradioactive technique for evaluation of the hemodynamics in large cerebral vessels. Sahyangsohap-won(SS) has been considered to be effective for the treatment of various disease, especially cerebrovascular, cardiovascular, and psychosomatoform disorders. But, there is no study about the effect of SS on the cerebral hemodynamics in humans. The aim of this study was to assess the effect of SS on the changes in cerebral hemodynamics and the dose-dependant effect by using TCD. Subjects and Methods : 30 healthy subjects were randomly divided into three group: group 1 took no drug, group 2 took SS one pill, and group 3 took SS 2 pills. Changes in the mean blood flow velocity(MBFV) and pulsatility index(PI) in the middle cerebral artery were evaluated by means of TCD. We obtained hypercapnia with breath-holding and evaluated cerebrovascular reactivity with the breath-holding index(BHI). Systolic blood pressure(SBP), diastolic blood pressure(DBP), and heart rate(HR) were measured by means of ambulatory blood pressure monitoring. In group 2 and group 3, the evaluations were performed during the baseline and were repeated at 20, 40, and 60 minutes after SS administration. In group 1, the evaluation was performed at corresponding time intervals. Results : In mean values of MSFV, PI, SSP, DBP, and HR, no stastically significant differences were found between the 3 groups. However, BHI values were significantly lower in groups 2 and 3 than in group 1 at 40 minutes after SS administration(P<0.05, group 1 vs group 2, group 1 vs group 3 by post-hoc analysis: Scheffe's test) but in dose-dependant effect, there was no difference between group 2 and group 3. Conclusion : These results suggest that SS can decrease vascular resistance in cerebral small arteries or arterioles and enhance their distensibility. Further studies on larger numbers of subjects are needed to confirm these effects and the dose-dependant effects.

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Effect of Exercises on the Cerebral Blood Flow (운동이 뇌 혈류 변화에 미치는 영향)

  • Song, Myung-Soo;Choi, Su-Hee
    • Journal of the Korean Academy of Clinical Electrophysiology
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    • v.1 no.2
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    • pp.1-9
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    • 2003
  • The purpose of this study was to analyze the effect given to the variable details which disturb the flow of blood in brain artery disease through Aerobic exercises. It chose the subjects of study : 5 persons in an exercise group and 5 persons in a non-exercise group. Peak brain blood velocity, mean velocity, and resistance & artery stricture ratio were measured with TCD, measure machine for brain artery blood flow. The conclusion of the study was as follows: 1. At pre-test of an exercises group and a non-exercise group, PBV, MBV, BRI, ASI of a non-exercise group were showed much lower in the variation of left common carotid artery(LCCA). 2. At post-test of an aerobic exercises group and a non-exercise group, PBV, MBV, BRI, ASI of a non-exercise group were showed just a little decrease ratio but were not significant different in the variation of left common carotid artery(LCCA). Viewing on the base of these result, continuing exercises promote the functional improvement of the heart blood system and were showed the positive variation of artery stricture ratio according to brain blood flow velocity, the pulse and resistance or blood velocity. Therefore programs for prescriptions through aerobic exercises must be developed in many ways.

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The Effects of Myofascial Relaxation on Blood Flow Velocity of the Cranial Artery and Pain Level in Cervicogenic Headache Patients (근막이완술이 경추성 두통환자의 뇌혈류와 통증수준에 미치는 영향)

  • Lee, Joon-Hee;Kang, Da-Haeng;Kang, Jeong-Il
    • The Journal of Korean Physical Therapy
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    • v.22 no.5
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    • pp.49-56
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    • 2010
  • Purpose: The aim of this study was to evaluate a possible role for cranial artery velocity in cervicogenic headache. Methods: We studied 13 patients with cervicogenic headaches (M=9, F=4, age=$24.50{\pm}3.50\;y$) these were compared to 20 normal subjects (M=10, F=10, age=$23.30{\pm}2.90\;y$). Cervicogenic headache patients were divided into two groups (a myofascial relaxation group, a placebo group). Pain levels were measured using a visual analog scale (VAS). Transcranial Doppler (TCD) ultrasound recordings were used to measure blood flow velocity in the cranial artery. Results: Cervicogenic headache patients exhibited a significantly lower blood flow velocity in the middle cerebral artery. The patients who received an intervention had a significantly higher blood flow velocity in the left middle cerebral artery, right vertebral artery and basilar artery. Compared to the placebo group, the myofascial relaxation group exhibited a significantly decreased level of pain. Conclusion: Cervicogenic headache is pain referred to the head from a source in the cervical spine. Manual therapy affect to cervical spine and soft tissue as well as the passage of these vessels and nerves to recover because it is thought to be able to help.

Reference Values of Transcranial Doppler Ultrasonography Measurement and Relation with Change Factor (Transcranial Doppler Ultrasonography(TCD)의 참고치와 변화 요인들과의 연관성)

  • Jung, Jong-An;Cho, Gook-Ryung;Kim, Nam-Uk;Kang, Chul-Sik;Jeon, Sang-Yun;Hong, Seok
    • The Journal of Internal Korean Medicine
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    • v.28 no.4
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    • pp.709-716
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    • 2007
  • Objective : We present reference values of flow velocities of intracranial and extracranial cerebral arteries and relation with change factor. Method : We checked transcranial Doppler ultrasonography on mean velocity, systolic velocity, pulsatility index, and resistance index of 252 patients. We also compared differences of change factor. Result : The result showed a difference by sex and age and relevance between vessels besides mean velocity of vessels related with past history and social history. Conclusion : According to the above results, females showed higher velocity of all vessels. With advancing age, subjects showed reduction in velocity and increase in pulsatility index and resistance index. Anterior cerebral, middle cerebral, and posterior cerebral artery increased in proportion to velocity of internal carotid artery and basilar artery. Vessel velocity correlated with diabetes mellitus, hypertension and hyperlipidemia.

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COMPOSITIONAL DEPENDENCE OF $128^{\circ}$ Y CUT $LiNbO_3$ CRYSTALS ON SAW CHRACTERISTICS ($128^{\circ}$ Y Cut $LiNbO_3$단결정의 조성비 변화에 따른 SAW특성변화)

  • 이상학;한재용;조순형;윤의박
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.2 no.1
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    • pp.30-36
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    • 1992
  • In order to measure the characteristics of Surface Acousitc Wave(SA W) with compositions of $LiNbO_3$ single crystal, $128^{\circ}$ Y cut wafer was fabricated from $LiNbO_3$ single crystals with the composition range of 47-50 $Li_2O$mol%. Delay lines were formed on the $128^{\circ}$ Y cut wafer using photolithography technique. Delay time was measured by pulse-echo overlap method. The compositional dependence of SAW characteristics, SAW velocity, electro-mechanical coupling coefficient$(K_s^2)$ and temperature coefficient of delay time(TCD), were investigated.

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The Effects of Suggestion on Cerebral blood flow velocity (암시가 정상인의 뇌혈류 속도에 미치는 영향)

  • Kang, Hee-Chul;Sun, Seung-Ho;Lee, Seung-Gi;Choi, Woo-Jin
    • Journal of Oriental Neuropsychiatry
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    • v.15 no.2
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    • pp.173-180
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    • 2004
  • Objectives : The purpose of this study is to investigate the change of cerebral blood flow velocity by different types of suggestion in normal subject. Methods : Suggestion of ascending qi inducement and descending qi inducement which were recomposed from autogenic training, was operated on 60 normal subjects individually. Then cerebral blood flow velocity was examined by Transcranial doppler ultrasonography(TCD) each 5 minutes before and after suggestion. Results : The result shows that cerebral blood flow(CBF) velocity was increased significantly in suggestion of ascending qi inducement and CBF velocity was decreased significally after 1 minute in suggestion of descending qi inducement. Conclusion : Suggestion could have affected to CBF velocity, and also different types of suggestion could have affected to the change of brain blood flow. Various clinical studies should be completed on patients in the future.

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Numerical Study on the Thermal Entrance Effect in Miniature Thermal Conductivity Detectors (소형 Thermal Conductivity Detector의 입구열전달 거동에 대한 수치해석)

  • Kim, U-Seung;Kim, Yeong-Min;Chen, Kuan;Cheon, Won-Gi
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.3
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    • pp.439-447
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    • 2002
  • The microchannel flow in miniature TCDs (thermal conductivity detectors) is investigated numerically. The solutions based on the boundary layer approximation are not very accurate in the region of the duct inlet for low Reynolds numbers. In this study, two-dimensional Navier-Stokes equations are considered to analyze the gas flow in a miniature TCD. Effects of channel size, inlet and boundary conditions on the heat transfer rate are examined. When the gas stream is not preheated, the distances for a miniature TCD to reach the conduction-dominant region for duct flow are found to be approximately two and three times the thermal entry length for duct flow with constant properties, respectively, leer constant wall temperature and constant wall heat flux boundary conditions. If the gas temperature at the channel inlet is close to the mean gas temperature in the conduction-dominant region, the entrance region is much shorter compared to other cases considered in this study.

Electrospinning Fabrication of Poly(vinyl alcohol)/TiO2 Nanofibers (전기방사를 이용한 Poly(vinyl alcohol)/TiO2 나노섬유 제조)

  • Kim, Young Hun;Do, Kook Bae;Choi, Jae Young;Rabbani, Mohammad Mahbub;Han, Sang Ik;Yeum, Jeong Hyun
    • Textile Coloration and Finishing
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    • v.25 no.2
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    • pp.118-125
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    • 2013
  • Poly(vinyl alcohol) (PVA)/titanium dioxide ($TiO_2$) composite nanofibers were produced at different $TiO_2$ concentrations (0.5, 1 and 1.5 wt.%) using the electrospinning method. The parameters of electrospinning including polymer contents, voltage and tip-to-collector distance (TCD) were optimized for fabrication process. The study showed that 7.5 wt.% PVA, 15 kV applied voltage and 15 cm TCD are the best condition to obtain uniform PVA/$TiO_2$ nanofibers. $TiO_2$ nanoparticles give significant effect in fiber morphology. $TiO_2$ content increases the diameter of the fibers and roughen the fiber surfaces. The PVA/$TiO_2$ nanofibers were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD).