• Title/Summary/Keyword: Channel effect

Search Result 3,517, Processing Time 0.033 seconds

Evaluation of Factors Affecting Glomerular Filtration Rate by Contrast Media in Patients with Coronary Angiography (심혈관 조영술 시행 환자의 조영제 사용 시 사구체여과율 변화에 영향을 미치는 인자들 평가)

  • Kim, Eun-Young;Lee, Ok-Sang;Lim, Sung-Cil
    • Korean Journal of Clinical Pharmacy
    • /
    • v.22 no.2
    • /
    • pp.103-112
    • /
    • 2012
  • Performance of coronary angiography for exact diagnosis and treatments of cardiovascular disease have been increased recently and it also brings increase of the contrast-induced nephropathy (CIN) referred from increasing use of radiological contrast agents. The variation of estimated glomerular filtration rate (eGFR) is an indicator of CIN, which is known to increase when renal function is decreased. Therefore, this study was to evaluate the affecting factors including concomitant drug on variation of eGFR of patients who underwent coronary angiography according to the conditions of renal function. Medical records of 66 patients were evaluated retrospectively and the patients underwent coronary angiography or angioplasty with nonionic and isotonic contrast media (iodixanol) at Chungnam national university hospital from 1 Jan 2008 to 30 Jul 2010. Patients group was divided into 2 groups; the patients in stages 3-4 chronic kidney disease (CKD) and the patients in stage 2 CKD. Each group was researched about the effect of concomitant drug and clinical characteristics on eGFR variation. The change of eGFR was compared among baseline and 2 or 3 day after coronary angiography. In results, the eGFR variation in group over age 75 was significantly decreased after radiological contrast agents exposure (p $$\leq_-$$ 0.05). The eGFR variation in anemia was significantly decreased after radiological contrast agents exposure in stage 2 CKD (p > 0.05). The eGFR variation in group under $HbA_{1c}$ 6.5% was significantly decreased after radiological contrast agents exposure in stages 3-4 CKD (p $$\leq_-$$ 0.05). The eGFR variation by taking statins, angiotensin converting enzyme inhibitors, calcium channel blockers and nitroglycerin was increased after radiological contrast agents exposure in stage 2 CKD (p $$\leq_-$$ 0.05). The eGFR variation by using of diuretics was significantly decreased after radiological contrast agents exposure in stages 3-4 CKD (p $$\leq_-$$ 0.05). The eGFR variation by taking statins, nitroglylcerin was increased after radiological contrast agents exposure in stages 3-4 CKD(p > 0.05). The eGFR variation in group over contrast dosage 150 ml was significantly decreased after radiological contrast agents exposure in stages 3-4 CKD (p $$\leq_-$$ 0.05). Therefore, when undergoing coronary angiography, contrast dosage should be minimized less than 150 ml, and diuretics should be restricted as possible in stages 3-4 CKD. Patients over age 75 require special attention to prevent CIN, and if patients undergo coronary angiography in stages 3-4 CKD, $HbA_{1c}$ is also requried to maintain below 6.5% to prevent CIN.

Spatial and Temporal Variability of Residual Current and Salinity according to Freshwater Discharge in Yeoungsan River Estuary (방류 유무에 따른 영산강 하구역의 시공간적 잔차류 및 염분 변화)

  • Kim, Jong-Wook;Yoon, Byung Il;Song, Jin Il;Lim, Chae Wook;Woo, Seung-Buhm
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.25 no.2
    • /
    • pp.103-111
    • /
    • 2013
  • In this study, field measurements were conducted in the section about 7 km from sea dike to westward. The observations of along channel current were carried out, and water temperature and salinity were measured simultaneously at 10 stations during one tidal cycle, and sampling interval is 1 hour. The maximum ebb current is about 1.5 m/s at the surface layer but flood current is 0.4 m/s at the bottom layer during discharge period. Residual current during river discharge shows two layer structures which is typical characteristic of the estuary system. On the other hand, residual current during a period with no discharge has shown multi-layer structure different from general estuarine systems. The distribution of high salinity can be seen at the bottom layer as the effect of discharge does not reach down to the bottom layer during discharge. As a result, freshwater is not effected at the bottom layer during observation, and mixing of surface layer to bottom layer is reduced by stratification.

Korean Youths' Use of Fastfood and Family Restaurants in Different Regions: a Comparison among Cities and Rural Towns (청소년의 패스트푸드점과 패밀리레스토랑 이용 실태 지역별 비교 연구)

  • Jo, Hye-Young;Kim, Sun-Ah
    • Journal of the Korean Society of Food Culture
    • /
    • v.20 no.1
    • /
    • pp.44-52
    • /
    • 2005
  • This study was conducted to investigate Korean youths' use of fastfood and family restaurants in different regions, especially among cities and rural towns. Total 1,600 questionnaire surveys were distributed to Junior high and Senior high school students and 1,487 were used for the analysis. In order to consider regional differences as well as overall characteristics of youths' fastfood and family restaurant visiting behaviors, the subjects were evenly sampled from north Seoul, south Seoul, big cities, middle/small cities and small towns. As for the frequency of visiting fastfood restaurants, 58.3% of the respondents answered 'once to five times' a week. South Seoul area showed the highest frequency. 'Easiness' was the main reason of eating fastfood, which was up to 57.8% of the overall respondents while 42.8% of the small town youth ate fastfood because of the 'good taste.' As for the concepts on fastfood, 42.7% understood it as 'easy to eat' while 33.6% responded as 'easy to get fat.' For the question of getting channel of fastfood information, 44.8% answered 'TV' and 28.3% responded 'from friends.' Coupons were found to affect fastfood restaurant visits, highest in south Seoul, and lowest in small cities. For the question of the relationship of Koreanized menus and fastfood restaurant visits, small towns showed the highest frequency, while South/North Seoul had the lowest frequency. For the percentage of visiting family restaurants, respondents answered in the order of South Seoul(59.7%), North Seoul(44.5%), Big cities(39.5%), small cities(19.4%), and small towns(13.1%). Most of youth visited family restaurants because of the taste, while youths of middle/small cities visited due to the atmosphere. The effect of coupons on visiting family restaurants were found to be lower than the one of fastfood restaurants. Korean youths were found to visit fastfood restaurants very frequently in all regions and the tendency of visiting family restaurants is also increasing. At this point, balanced menus and education for healthy eating habits are urgently needed for the youth.

Deformation of Cage Nets against Flow Velocity and Optimal Design Weight of Sinker (우리형 그물의 유속에 따른 변형 및 적정 침자량)

  • 김태호;김재오;김대안
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.37 no.1
    • /
    • pp.45-51
    • /
    • 2001
  • In order to investigate the optimal design weight of sinkers for preventing cage net from deforming in current, the model experiment on 2 types of square cage nets with different S sub(n)/S, the ratio of total area of netting projected to the perpendicular to the water flow S sub(n) to wall area of netting S, and 4 kinds of sinkers was carried out in circulation water channel. The model cage nets were made in 1/10 scale and the total weight in water of 4 sinkers attached to each corner of their bottom frames was 18, 54, 90, and 126g, respectively equivalent to 0.1, 0.3, 0.5, and 0.7 kg per unit area of prototype net. The results obtained can be summarizes as follows; Due to the deformation of each net where it was lifted towards the surface in severe conditions, its volume was reduced. This depended highly on the weight of sinkers placed in the bottom corner of cage nets, even if the variation of S sub(n)/S had a little effect on their deformation in current less than 0.4 m/s. In addition, it was observed that the total weight of sinkers for preventing the net from deforming to the extent of less than 50% inside its initial volume was 31 to 245 kg in the range of 0.3 to 0.6 m/s and the adequate design weight of sinker was approximately 0.5 kg per its unit area.

  • PDF

An approximate study on flood reduction effect depending upon weir or gate type of lateral overflow structure of washland (강변저류지 월류부에서 월류제 또는 수문 형식에 따른 홍수저감효과에 관한 개략적 연구)

  • Ahn, Tae Jin
    • Journal of Wetlands Research
    • /
    • v.15 no.4
    • /
    • pp.573-583
    • /
    • 2013
  • Construction of large-scale structures such as dams would be suggested actively to cope with change of flood characteristics caused by climate change. However, due to environmental, economic and political issues, dams are not ideally constructed. Thus flood damage reduction planning projects would get started including washland or detention pond for sharing the flood in basin. The washland made artificially by human being is an area of floodplain surrounded by bank to be intentionally inundated by overflowing through overflow structure adjacent to main channel during flood season. Flood reduction capacity at just downstream of each washland could be affected by type, length, and crest elevation of overflow structure in addition to shape of design hydrograph, storage volume of washland, etc.. In this study flood reduction effects of washland are estimated for overflow weir type and gate type to compare the results of flood reduction respectively subjected to given hydrograph in sample site, the Cheongmicheon stream. It has been shown that even if gate type at overflow structure could yield more flood reduction than overflow weir type, economic aspect such as initial cost, operation cost and maintenance cost should be considered to select the type of overflow structure because flood reduction rate by gate type could not be significant value from engineering point of view.

An analysis on stability of riprap considering hydraulic characteristics of flow around joint revetment (연결호안 주변 흐름의 수리적 특성을 고려한 사석호안의 안정성 분석)

  • Kim, Sooyoung;Kim, Hyung-Jun;Yoon, Kwang Seok
    • Journal of Korea Water Resources Association
    • /
    • v.49 no.12
    • /
    • pp.1035-1044
    • /
    • 2016
  • In joint portions of the levee and the barrier, complex 3-dimensional flow was generated and collapse of revetment occurred frequently. For these reasons, it is necessary to install the joint revetment with greater stability as compared with the general revetment at the joint portions. However, design criteria for joint revetment was not presented in River Design Criteria (KWRA, 2009). Therefore it is necessary to research for engineering design of the joint revetment. In this study, hydraulic experiments were performed under various flow conditions in order to realize the collapse conditions of riprap and carried out in 20.0 m straight open channel with one side levee and the width was 4.0 m. The diameter of riprap covered around joint revetment was 0.03 m and the inlet discharges were $0.5{\sim}0.8m^3/s$. The numerical simulations were performed under same conditions with experiment. as results of this numerical simulations, the influence range was confirmed from the distribution of flow characteristics and shear stress. As a result, the riprap diameter of the joint revetment was calculated from 4.1 to 6.9 times greater than that of general revetment. As the inlet discharge was large, the range of vulnerable area was developed long in the downstream direction despite of same withdrawal velocity of riprap. Through this study, the methods of calculating the riprap diameter and influence range were proposed according to hydraulic characteristics of flow around joint revetment. At a later study, if additional experiments about effect of flood plane and various types of barrier is applied, it is expected that rational design method with stability of joint revetment can be proposed.

Characteristics of hypoxia-induced ANP Secretion in Perfused Beating Atria (허혈성 자극에 의한 심방이뇨 호르몬 분비 반응의 특성)

  • Kim, Kong-Soo;Kim, Min-Ho;Kim, Chang-Gon;Kim, Suk-Kee;Cho, Kyung-Woo;Cui, Xun
    • Journal of Chest Surgery
    • /
    • v.33 no.5
    • /
    • pp.398-406
    • /
    • 2000
  • Background: Cardiac atrium is an endocrine gland secreting a family of natriuretic peptides. The secretion of atrial natriuretic peptide(ANP) had been shown to be controlled by variable factors. The change in atrial dynamics have been considered as one of the most prominent stimuli for the stimulation of ANP secretion. Hypoxic stress has been shown to increase cardiac ANP secretion. However, the mechanism by which hypoxia increases ANP secretion cardiac ANP secretions. However, the mechanism by which hypoxia increases ANP secretion has not to be defined. Therefore, the purpose of the present study was tow-fold: to develop a protocol to defined the effect of hypoxia on ANP secretion in perfused beating rabbit atria and to clarify the mechanism responsible for the accentuation by hypoxia of ANP secretion. Material and Method: Experiments have been done in perfused beating rabbit atria. ANP was measured by radioimmunoassay. Result: Hypoxic stimulus with nitrogen decreased atrial stroke volume. The decrease in atrial stroke volume recovered basal level during the period of recovery with oxygen. ANP secretion and the concentration of perfusate ANP in terms of extracellular fluid(ECF) translocation which reflects the rate of myocytic release of ANP were increased by hypoxia and returned to basal levels during the recovery. Changes in ECF translocation paralleled by hypoxia and returned to basal levels during the recovery. Changes in ECF translocation paralleled to that of atrial stroke volume. At the start of recovery in atrial storke volume, ECF tranalocation incrased for several minutes. The above responses were stable and reproducible. Glibenclamide treatment prevented the recovery in atrial stroke volume. Increments by hypoxia of ANP secretion and ANP concentration were suppressed by glibenclamide. Conclusion: These results indicate that hypoxia incrased atrial myocytic ANP release and that the mechanism responsible for the accentuation is partially related to the change in K+ATP channel activity.

  • PDF

Application of DC Resistivity Survey from Upper Portion of Concrete and Geostatistical Integrated Analysis (콘크리트 상부에서 전기비저항 탐사 적용 및 지구통계학적 복합 해석)

  • Lee, Heuisoon;Oh, Seokhoon;Chung, Hojoon;Noh, Myounggun;Ji, Yoonsoo;Ahn, Taegyu;Song, Sung-Ho;Yong, Hwan-Ho
    • Journal of the Korean earth science society
    • /
    • v.35 no.1
    • /
    • pp.29-40
    • /
    • 2014
  • A DC resistivity survey was performed to detect anomalies beneath concrete pavement. A set of high conductive media and planar electrodes were used to lessen the effect's a high contact resistance of concrete. Results of the resistivity survey were analyzed and compared with those of other geophysical surveys such as Ground Penetration Radar (GPR), Impulse Response (IR), and Multi-channel Analysis of Surface Waves (MASW), which were carried out in the same location. The results of resistivity survey showed a high resistive distribution in the section of sink and pavement where a pattern of reinforcement was observed through the GPR survey. Also, a comparison of results between the IR and resistivity surveys indicated that the high resistivity was produced by the high dynamic stiffness in the reinforced section. The co-Kriging of both the results of DC resistivity and MASW surveys at the same location showed that an integrated geostatistical analysis is able to give more accurate description on the anomalous subsurface region than can a separate analysis of each geophysical approach. This study suggests that the integrated geostatistical approaches were used for a decision-making process based on the geophysical surveys.

A Study on the Comparison and Analysis of Debris Reduction System on Small Bridge (소교량 유송잡물 저감시설의 비교 분석 연구)

  • Kim, Sung-Joong;Jung, Do-Joon;Kang, Joon-Gu;Yeo, Hong-Koo;Kim, Jong-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.17 no.3
    • /
    • pp.31-41
    • /
    • 2016
  • Damage to structures, such as bridge piers, are increasing rapidly due to the debris moving along rivers at the time of flooding. Therefore, the debris fin, debris deflector and debris sweeper, which are debris reduction systems, were produced in this study and an accumulation experiment was carried out on the experimental channel according to the existence of the reduction system. The debris fin is the reduction system that creates parallel flow on debris accumulated on the bridge to pass through the bridge, which was produced using wood. In addition, the debris deflector was produced using steel pipes and it has the type of detouring the direction of debris. The debris sweeper passes the debris using the magnetic force rotation of a screw-shaped cylindrical structure by water flow and it was produced using acrylic material. The experiment was carried out by analyzing the level of accumulation according to the hardness and dropping method of the debris and comparing the accumulation rate of reduction systems, and the experiment was carried out 5 times. According to the experimental results, there was a difference in the accumulation rate according to the type of reduction system and the shape of debris, and it often depended significantly on the initial shape of debris accumulation. The direct debris reduction effect on the bridge was higher in the order of the debris deflector, debris sweeper and debris fin, but in case of the debris deflector, damage, such as stream turbulence, changes in water level and river bed, and the loss of deflector can occur due to debris accumulated directly on the debris deflector. Therefore, it is necessary to design the debris deflector considering these issues.

The Effects of Jungchun-tang and Jungchuntanggagambang on Immune Cell & Serum IgE in BALF in a Rat Asthma Model (정천탕과 정천탕가감방이 알레르기 천식모델 흰쥐의 BALF내 면역세포 및 혈청 IgE에 미치는 영향)

  • 염종훈;정희재;정승기;이형구
    • The Journal of Korean Medicine
    • /
    • v.24 no.1
    • /
    • pp.169-180
    • /
    • 2003
  • Background : Allergic asthma is thought to be mediated by $CD4^{+}$ T lymphocytes producing the Th2-associated cytokines. According to investigations of lung biopsies and respiratory secretions from patients, $CD4^{+}$ T cells and eosinophils are the main features of the inflammatory process. Object : This study aimed to find an inhibition effect on allergens induced by JCT (Jungchun-tang) and JCTG (Jungchuntanggagambang) through the change of $CD4^{+}$ T cells and $CD8^{+}$ T cells in BALF of rat, and to see the change of IgE m serum. Materials and Methods : Laboratory rats were primary sensitized with OA (ovalbumin); on day 1, rats of a control group and a sample group (SBP group) were systemically immunized by subcutaneous injection of 1mg OA and 300mg of A1(OH)3 in a total volume of 2 ml saline. The rats of the sample group were orally administered with an SBP water extract for 14 days after primary immunization. On day 14 after the systemic immunization, rats received local immunization by inhaling 0.9% saline aerosol containing 2%(wt/vol) OA. A day after local immunization, BAL fluid and serum were collected from the rats. Total cells, lymphocytes, $CD4^{+}$ T cells, $CD8^{+}$ T cells, and $CD4^{+}$/$CD8^{+}$ ratio in the BALF, and IgE level in serum were measured and evaluated. Results : L Total cell in BALF of rat : JCT was observed to be significantly reduced but JCTG had no significant difference in comparison with the control group. 2. Lymphocytes in BALF of rat : JCT and JCTG were observed to be significantly reduced in comparison with the control group. 3. $CD4^{+}$T cells in BALF of rat : JCT was observed to be more significantly reducing than JCTG in comparison with the control group. 4. $CD8^{+}$T cells in BALF of rat : JCT and JCTG were observed not to be significantly different than in the control group. 5. $CD4^{+}/CD8^{+}$ ratio in BALF of rat : JCT and JCTG were observed not to be significantly different than in the control group. 6. The IgE level in serum : JCT and JCTG were observed to be significantly reduced in comparison with the control group. Conclusion : This study shows that JCT inhibits allergen-induced specially select $CD4^{+}$T cell channel in BALF of rat.

  • PDF