• Title/Summary/Keyword: Small Vessels

Search Result 569, Processing Time 0.028 seconds

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
    • /
    • v.22 no.2
    • /
    • pp.199-205
    • /
    • 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.

  • PDF

A Study of Carry Over Contamination in Chematology (이월오염에 대한 연구)

  • Chang, Sang-Wu;Kim, Nam-Yong;Lyu, Jae-Gi;Jung, Dong-Jin;Kim, Gi-You;Park, Yong-Won;Chu, Kyung-Bok
    • Korean Journal of Clinical Laboratory Science
    • /
    • v.37 no.3
    • /
    • pp.178-184
    • /
    • 2005
  • Carry over contamination has been reduced in some systems by flushing the internal and external surfaces of the sample probe with copious amount of diluent. It between specimens should be kept as small as possible. A built-in, continuous-flow wash reservoir, which allows the simultaneous washing of the interior and exterior of the syringe needles, addresses this issue. In addition, residual contamination can further be prevented through the use of efficient needle rinsing procedures. In discrete systems with disposable reaction vessels and measuring cuvets, any carry over is entirely caused by the pipetting system. In analyzers with reuseable cuvets or flow cells, carry over may arise at every point through which high samples pass sequentially. Therefore, disposable sample probe tips can eliminate both the contamination of one sample by another inside the probe and the carry over of in specimen into the specimen in the cup. The results of the applicative carry over experiment studied on 21 items for total protein (TP), albumin (ALB), total bilirubin (TB), alkaline phosphatase (ALP), aspratate aminotranferase (AST), alanine aminotranferase (ALT), gamma glutamyl transferase (GGT), creatinine kinase (CK), lactic dehydrogenase (LD), creatnine (CRE), blood urea nitrogen (BUN), uric acid (UA), total cholesterol (TC), triglyceride (TG), glucose (GLU), amylase (AMY), calcium (CA), inorganic phosphorus (IP), sodium (Na), potassium (K), chloride (CL) tests in chematology were as follows. Evaluation of process performance less than 1% in all tests was very good, but a percentage of ALB, TP, TB, ALP, CRE, UA, TC, GLU, AMY, IP, K, Na, and CL was 0%, implying no carry over. Other tests were ALT(-0.08%), GGT(-0.09%), CK(0.08%), LD(0.06%), BUN(0.12%), TG (-0.06%), and CA(0.89%).

  • PDF

The Prospect of the Development of Sea&Air Transportation Routes around the Yellow Sea Regions (환황해권 Sea&Air 수송의 발전 가능성 전망)

  • Kim, Tae-Seung;Won, Dong-Woo;Yun, Jung-Won
    • Journal of Korea Port Economic Association
    • /
    • v.22 no.3
    • /
    • pp.189-207
    • /
    • 2006
  • As the development of Northeast Asian logistics hub becomes one of the national agenda for further development, the sea&Air transport around the Yellow Sea regions has drawn attention of many scholars and government officials. The Sea&air transport is a mode of transportation combining the advantage of high-speed in air transport with the advantage of low-price in sea transport. Hence the sea&air aims at a niche market between air and sea. This paper reviews the possibility of development of the sea&air transport in the aspects of competitiveness over other modes, future demand condition, and the change of the technology and transport environment. The result is that the sea&air is competitive in the aspect of time as well as cost, and sustainable in the aspect of future demand condition. But, it is not stable in the aspect of the conditions of technology or transport demand. Especially, the progress of air transport technology which is aiming at the door-to-door transport among mid- and small- cities, and the rapidly increasing strategic alliances of international airlines with Chinese airlines for the market of China will undermine the stability of the sea&air transport seriously As alternatives, this paper proposes the 3-stage development strategy of sea&air transport. First, at the stage of transshipement, the development of high speed vessels to reduce the time crossing the Yellow Sea and the proactive marketing strategy to induce Chinese-owned products should be emphasized. Second, the value added logistics activity which will secure the demand of the sea&air transport should be developed. Third, demand creation by developing the SCM hub in Incheon is final goal for the logistics hub strategy as well as the sea&air transport.

  • PDF

A Study on Analysis of Container Liner Service Routes Pattern Using Social Network Analysis : Focused on Busan Port (사회연결망 분석을 이용한 컨테이너 정기선 항로 패턴 분석에 관한 연구 : 부산항을 중심으로)

  • Ryu, Ki-Jin;Nam, Hyung-Sik;Jo, Sang-Ho;Ryoo, Dong-Keun
    • Journal of Navigation and Port Research
    • /
    • v.42 no.6
    • /
    • pp.529-538
    • /
    • 2018
  • The port industry is an important national industry which significantly affects Korea's imports and exports which are centered on economic structure. For instance, the Port of Busan, which handles 75% of domestic container freight volume, is expected to become increasingly critical for container liner routes. For this reason, there have been continued efforts to expand freight service to attract international freight volume. This study analyzes the structural characteristics of the port network connected to the Port of Busan by analyzing the pattern of the container liner route from 2012 to 2016 by using social network analysis. According to the Port of Busan's liner route network, the port with the highest degree of centrality, closeness centrality, and betweenness centrality was found to be the Port of Singapore. The comparison of Busan's annual container handling rank by countries and the port center network analysis of Port of Busan rank was found to be different. As a result, it was established that China's East Port, which occupies a high percentage of the volume of cargo handled by Port of Busan, is not a hub port of Busan when viewed on the Busan's container terminal liner network. In addition, even if the number of Port of Busan container liner service increases, it is estimated that the vessels to be added to the fleet will be limited to small to medium sized, or that Busan port has characteristic of a feeder port for the Port of Singapore, according to the network.

Vessel and Navigation Modeling and Simulation based on DEVS Formalism : Design for Navigation Simulation Architecture with Modeling for Critical Systems and Agents of Vessel (DEVS 형식론 기반의 선박 항해 모델링 및 시뮬레이션 (I) : 항해 시뮬레이션 아키텍처 설계와 선박 핵심 장비 및 에이전트 모델링)

  • Woo, Sang-Min;Lee, Jang-Se;Hwang, Hun-Gyu
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.23 no.9
    • /
    • pp.1038-1048
    • /
    • 2019
  • Recently, various systems have been developed to support ship navigation safety. In order to verify the usefulness of such a system, it is most ideal to try it on a real vessel, but there are many difficulties. As an alternative, usability verification methods applied with modelling and simulation (M&S) techniques are required such as FMSS, which is closest to reality, is very expansive to construct, and there needs the specialized operator. For this reason, this paper proposes a method to verify the navigation safety support system by modeling and simulation techniques based on the Discrete Event System Specification (DEVS) formalism. As a first step, we designed the navigation simulation architecture based on the SES/MB framework, and details on modelling ship core equipment and navigator agents based on the DEVS. Through this, we are able to implement the navigation simulation system for vessels, and evaluate the effectiveness of navigation safety support elements such as collision avoidance, etc. using developed scenarios.

Study on the Identification of Ship Maneuverability Required for Navigational Officers based on AHP Analysis (AHP 분석 기반 항해사 필요 선박조종성능 식별 연구)

  • Kang, Suk-Young;Ahn, Young-Joong;Yu, Yong-Ung;Lee, Yun-Sok
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.28 no.5
    • /
    • pp.800-808
    • /
    • 2022
  • The International Maritime Organization adopted the interim standards for ship maneuverability in November 1993 for preventing collision of ships at sea and for protecting the marine environment, and based on the accumulated data, in December 2002, the established standards for ship maneuverability were adopted. However, the standards adopted are those at full load, even keel, and at least 90 % of the ship speed at 85 % of the ship's maximum power. Moreover, these standards have limitations in providing information on maneuverability under actual navigational conditions. Therefore, in this study, frequency analysis AHP analysis techniques were studied by consulting navigational officers, captains, and experts, who have significant knowledge on ship maneuverability, utilization of the current standards, and the information necessary for the operation of the actual ship. The results of this study confirmed that the necessary information on maneuverability for the navigational officer operating the vessel is information about the turning circle at a small angle of 5°-10° and z-test information at maneuvering speed, not sea speed. Additionally, in relation to speed control, additional information on deceleration inertia and acceleration inertia is needed than the information on the stopping ability at sea speed and full loaded condition. The derived results are considered to be useful as basic data for preparing guidelines for ship maneuverability necessary for navigational of icers who operate ships.

A Study on External.Internal Morphology and Pattern Analysis of Atractylodes Rhizomes (출류(朮類) 한약재의 외.내부형태와 이화학패턴 연구)

  • Kim, Jung-Hoon;Lee, Guem-San;Choil, Goya;Hwang, Sung-Yeoun;Kim, Hong-Jun;Jeong, Seung-Il;Ju, Young-Sung
    • The Korea Journal of Herbology
    • /
    • v.24 no.2
    • /
    • pp.77-85
    • /
    • 2009
  • Objectives : To determine the discriminative criteria for Atractylodes rhizomes, the experiment of externalinternal characteristics and physicochemical pattern analysis were performed. Methods : External characteristics was observed using stereoscope. The sectioned materials which were covered with parffin were stained by Ju's method. Physicochemical patterns were analyzed using HPLC/DAD. Results : 1. External shape of original plant : Atractylodes maaocephala and A. japonica had relatively long petioles and 3-5 parted leaves. A. macrocephala had big purple flowers whereas A. japonica had relatively small white flowers and pinnate bracts. A. lancea had sessile leaves and white flowers, and the end parts of degenerated stamens were bent. 2. External shape of herbal medicine: A. macrocephala which was fist-shaped rhizome had pa-pillate processes and the cross section was light gray and sulcate. A. japonica and A. lancea were connected-beady or tubercular rhizomes, and the cross sections were both yellow-colored white. However, the cross section of A. japonica was fibrous, the width of cortex was narro-wer than that of stele, and radial shape in cortex was rare, whereas the width of cortex in A. lancea was similar to that of stele in size, and radial shape in cortex was obvious. 3. Internal shape of herbal medicine: A. macrocephala and A. lancea did not have lignified fascicles in cortex. However, the vascular bundles and vessels of A. macrocephala were wedge shaped and radial arrangement, and vascular bundles were densely populated in stele whereas those of A. lancea were repeatedly arranged and thinly extended to cortex. A. japonica had lignified fascicles in cortex and the width of vascular bundles was conspicuously thick with narrow intervals. 4. Physicochemical pattern analysis : A. macrocephala and A. lancea contained atractylenolide I and atractylenolide Ill whereas A. japonica contained atractylenolide I, atractylenolide Ill. diacetyl-atractylodiol, compound-4, compound-5. The three species of Atractylodes rhizomes showed different chromatogram patterns. Conclusions : The results could be used as discriminative criteria for Atractylodes rhizomes and as fundamental materials to researches of further pattern analysis and biological reaction.

Increased Utilization of LTE-Maritime Networks Based on User Requirements (사용자 요구사항 기반 초고속 해상무선통신망 활용성 증대 방안에 대한 연구)

  • Sangjin JANG;Bu-Young KIM;Si-Hwan LEE;Hyo-Jeong KIM;Taehan SONG;Woo-Seong Shim
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.29 no.7
    • /
    • pp.812-818
    • /
    • 2023
  • During the years 2016 to 2020, the Ministry of Oceans and Fisheries embarked on a strategic initiative to develop a comprehensive Korean e-navigation system, which encompassed the establishment of an 'Long Term Evolution for Maritime (LTE-M).' The primary objectives were to proactively align with international navigation standards and enhance maritime safety for small vessels, particularly fishing boats. However, limitations were identified in the utilization of this network, primarily its constrained application for specific purposes. In response to these limitations, this study delves into user-centric investigations through surveys and interviews, with the goal of expanding the horizon of network utilization. User requirements emerged as the result of study, emphasizing the need for broader network applications, a wider range of target users, diverse network utilization methods, and regulatory streamlining. The user-driven insights gleaned from this study hold the potential to inform and shape future legislative measures, fostering more versatile and inclusive LTE-M network utilization for enhanced maritime safety.

Development of the Large-Capacity Mooring Fittings according to MEG4(Mooring Equipment Guideline 4) (MEG4(Mooring Equipment Guideline 4) 적용에 따른 대용량 무어링 피팅 개발)

  • Myung-Su Yi;Kwang-Cheol Seo;Joo-Shin Park
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.29 no.7
    • /
    • pp.950-957
    • /
    • 2023
  • For safe mooring and towing between the ship and port, the equipment must be designed in accordance with the relevant international regulations. However, some small shipyards and engineering companies often do not fully comprehend the core contents. Therefore, the international regulations regarding towing and mooring equipment are reviewed and the bollard and chock are newly developed based on the Mooring Equipment Guideline 4 (MEG4) standards. A bollard is a mooring equipment used to fix a mooring rope to the hull. It has two columns and is mostly used in a figure eight pattern knots under the mooring condition. The chock, which is used to change the mooring rope direction coming into the ship from outside, is manufactured using a casting with curvature. The two mooring equipment are widely used in the stern, bow, and mid-side. Owing to the increase in the size of container vessels and LNG ships, the mooring rope load has increased and the safe working load of the mooring equipment must be revised. This study summarizes and examines the results of the allowable stress method obtained using finite element analysis modelling. To consider the mesh size effect, a reasonable criteria was suggested by referring the existing class guidance. Additionally, the safe working load was verified through nonlinear collapse analysis, and the elastic region against load increments was confirmed. Furthermore, the proposed evaluation method can be used to develop similar equipment in the near future.

Feasibility of Single-Shot Whole Thoracic Time-Resolved MR Angiography to Evaluate Patients with Multiple Pulmonary Arteriovenous Malformations

  • Jihoon Hong;Sang Yub Lee;Jae-Kwang Lim;Jongmin Lee;Jongmin Park;Jung Guen Cha;Hui Joong Lee;Donghyeon Kim
    • Korean Journal of Radiology
    • /
    • v.23 no.8
    • /
    • pp.794-802
    • /
    • 2022
  • Objective: To evaluate the feasibility of single-shot whole thoracic time-resolved MR angiography (TR-MRA) to identify the feeding arteries of pulmonary arteriovenous malformations (PAVMs) and reperfusion of the lesion after embolization in patients with multiple PAVMs. Materials and Methods: Nine patients (8 females and 1 male; age range, 23-65 years) with a total of 62 PAVMs who underwent percutaneous embolization for multiple PAVMs and were subsequently followed up using TR-MRA and CT obtained within 6 months from each other were retrospectively reviewed. All imaging analyses were performed by two independent readers blinded to clinical information. The visibility of the feeding arteries on maximum intensity projection (MIP) reconstruction and multiplanar reconstruction (MPR) TR-MRA images was evaluated by comparing them to CT as a reference. The accuracy of TR-MRA for diagnosing reperfusion of the PAVM after embolization was assessed in a subgroup with angiographic confirmation. The reliability between the readers in interpreting the TR-MRA results was analyzed using kappa (κ) statistics. Results: Feeding arteries were visible on the original MIP images of TR-MRA in 82.3% (51/62) and 85.5% (53/62) of readers 1 and 2, respectively. Using the MPR, the rates increased to 93.5% (58/62) and 95.2% (59/62), respectively (κ = 0.760 and 0.792, respectively). Factors for invisibility were the course of feeding arteries in the anteroposterior plane, proximity to large enhancing vessels, adjacency to the chest wall, pulsation of the heart, and small feeding arteries. Thirty-seven PAVMs in five patients had angiographic confirmation of reperfusion status after embolization (32 occlusions and 5 reperfusions). TR-MRA showed 100% (5/5) sensitivity and 100% (32/32, including three cases in which the feeding arteries were not visible on TR-MRA) specificity for both readers. Conclusion: Single-shot whole thoracic TR-MRA with MPR showed good visibility of the feeding arteries of PAVMs and high accuracy in diagnosing reperfusion after embolization. Single-shot whole thoracic TR-MRA may be a feasible method for the follow-up of patients with multiple PAVMs.