• Title/Summary/Keyword: 2-Stroke

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Experimental Study on Reduction of Particulate Matter and Sulfur Dioxide Using Wet Electrostatic Precipitator (습식전기집진기를 활용한 입자상 물질 및 황산화물 저감 성능에 관한 실험적 연구)

  • Kim, Jong-Lib;Oh, Won-Chul;Lee, Won-Ju;Choi, Jae-Hyuk
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.27 no.6
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    • pp.898-904
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    • 2021
  • This experimental study aims to investigate the use of a wet electrostatic precipitator as a post-treatment device to satisfy the strict emission regulations for sulfur oxides and particulate matter (PM). The inlet/outlet of a wet electrostatic precipitator was installed in a funnel using a marine four-stroke diesel engine (STX-MAN B&W) consuming marine heavy fuel oil (HFO) with a sulfur content of about 2.1%. Measurements were then obtained at the outlet of the wet electrostatic precipitator; an optical measuring instrument (OPA-102), and the weight concentration measurement method (Method 5 Isokinetic Train) were used for the PM measurements and the Fourier transform infrared (FT-IR; DX-4000) approach was used for the sulfur oxide measurements. The experimenst were conducted by varying the engine load from 50%, to 75% and 100%; it was noted that the PM reduction efficiency was a high at about 94 to 98% under all load conditions. Additionally, during the process of lowering the exhaust gas temperature in the quenching zone of the wet electrostatic precipitator, the sulfur dioxide (SO2) values reduced because of the cleaning water, and the reduction rate was confirmed to be 55% to 81% depending on the engine load.

The Protective Effects of Statins towards Vessel Wall Injury Caused by a Stent Retrieving Mechanical Thrombectomy Device : A Histological Analysis of the Rabbit Carotid Artery Model

  • Lee, Seung Hwan;Shin, Hee Sup;Oh, Inho
    • Journal of Korean Neurosurgical Society
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    • v.64 no.5
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    • pp.693-704
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    • 2021
  • Objective : Endovascular mechanical thrombectomy (MT) has been regarded as one of the standard treatments for acute ischemic stroke caused by large vessel occlusion. Despite the wide use of stent retrievers for MT, arterial intimal damage caused when deployed stent is pulled has been a certain disadvantage. We hypothesized that statin could protect and stabilize vessel damage after endovascular MT using a stent retriever. In this animal study, we observed the protective effects of the statins towards MT-induced vessel wall injury. Methods : Twenty-eight carotid arteries of fourteen rabbits were used in the experiments with MT using stent retriever. We divided the rabbits into four groups as follows : group 1, negative control; group 2, positive control; group 3, statin before MT; and group 4, statin after MT. After MT procedures, we harvested the carotid arteries and performed histomorphological and immunohistochemical analyses. Results : In histomorphological analysis with hematoxylin and eosin and Masson's trichrome stain, significant intimal thickening (p<0.05) was observed in the positive control (group 2), compared to in the negative control (group 1). Intimal thickening was improved in the statin-administered groups (groups 3 and 4 vs. group 2, p<0.05). We also observed that statin administration after MT (group 4) resulted in a more effective decrease in intimal thickness than statin administration before MT (group 3) (p<0.05). We performed immunohistochemical analysis with the antibodies for tumor necrosis factor-alpha (TNF-α), cluster of differentiation (CD)11b, and CD163. In contrast to the negative control (group 1), the stained percentage areas of all immunological markers were markedly increased in the positive control (group 2) (p<0.05). Based on statin administration, the percentage area of TNF-α staining was significantly reduced (p<0.05) in group 3, compared to the positive control group (group 2). However, significant differences were not observed for CD11b and CD163 staining. In group 4, no significant differences were observed for TNF-α, CD11b, and CD163 staining (p≥0.05). The differences in the percentage areas of the different markers between the statin-administered groups (groups 3 and 4) were also not revealed. Conclusion : We presented that statin administration before and after MT exerted protective effects towards vessel wall injury. The efficacy of statins was greater post-administration than pre-administration. Thus, statin administration in routine prescriptions in the peri-procedural period is strongly advised.

Hospital-based home care reinbursement and service use for the elderly (노인의 의료기관 가정간호 급여청구 및 서비스 이용 현황)

  • Chin, Young-ran
    • 한국노년학
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    • v.29 no.2
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    • pp.645-656
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    • 2009
  • The purpose of this study was to address the current status of hospital-based home care(HBHC). We analyzed the data on HBHC from national electronic data information of Health Insurance Review Agency. Beside, we surveyed 75 hospital-based home care agency. In 2006, 20,343 elderly(64.0% from all HBHC user) used 333,889 visits(76.8%from all visits). Medical diagnosis was composed of circulatory disease including cerebrovascular diseases 41.3%, endocrine system disease including Diabetes mellitus 10.4%, neoplasm 9.7%. Some of subjects used HBHC in excess of maximum covered 8 visits a month by National Health Insurance, decubitus 7.0%, the cancer 5.4%, the diabetes 2.5%, the hypertension 1.1%, and the stroke 0.9%. This results will contribute to expand the coverage of hospital-based home care by National Health Insurance. There was distribution difference in medical diagnosis and nursing intervention between HBHC and Public health center-based home care(PBHC) subjects. Therefore, HBHC subjects had more severe medical diagnosis, and were intervened more injections, examinations, than PBHC subjects. These differences must be considered to set up functional role among the three types of home visit care.

Anti-thrombotic effect of artemisinin through regulation of cAMP production and Ca2+ mobilization in U46619-induced human platelets (U46619 유도의 사람 혈소판에서 cAMP 생성 및 Ca2+동원의 조절을 통한 Artemisinin의 항혈전 효과)

  • Chang-Eun Park;Dong-Ha Lee
    • Journal of Applied Biological Chemistry
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    • v.66
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    • pp.402-407
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    • 2023
  • The regulation of platelet aggregation is crucial for maintaining normal hemostasis, but abnormal or excessive platelet aggregation can contribute to cardiovascular disorders such as stroke, atherosclerosis, and thrombosis. Therefore, identifying substances that can control or suppress platelet aggregation is a promising approach for the prevention and treatment of these conditions. Artemisinin, a compound derived from Artemisia or Scopolia plants, has shown potential in various areas such as anticancer and Alzheimer's disease research. However, the specific role and mechanisms by which artemisinin influences platelet activation and thrombus formation are not yet fully understood. This study investigated the effects of artemisinin on platelet activation and thrombus formation. As a result, cAMP production were increased significantly by artemisinin, as well as phosphorylated VASP and IP3R which are substrates to cAMP-dependent kinase by artemisinin in a significant manner. The Ca2+ normally mobilized from the dense tubular system was inhibited due to IP3R phosphorylation from artemisinin, and phosphorylated VASP by artemisinin aided in inhibiting platelet activity via αIIb/β3 platelet membrane inactivation and inhibiting fibrinogen binding. Finally, artemisinin inhibited thrombin-induced thrombus formation. Therefore, we suggest that artemisinin has importance with cardiovascular diseases stemming from the abnormal platelets activation and thrombus formation by acting as an effective prophylactic and therapeutic agent.

The Age-Related Trend in Blood Pressure and the Prevalence of Hypertension in Korean Adults (한국 성인의 연령에 따른 혈압변화 양상과 고혈압 유병률)

  • Lee, Dae-Taek;Lee, Yong-Soo
    • Journal of Life Science
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    • v.22 no.2
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    • pp.148-155
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    • 2012
  • A cross-sectional analysis of blood pressure (BP) changes and the current prevalence and distribution of hypertension among age groups in Korea were conducted. Systolic (SBP), diastolic (DBP), and pulse (PP) pressures were evaluated. Residents visiting a local Community Health Center for a health check-up and/or participating in the Health Promotion Program were included for the analyses. A total of 6,570 subjects (2,809 men, 3,761 women) were divided into five age groups: 30-39, 40-49, 50-59, 60-69, and $70\leq$ years. Comparisons were made between sex and among age groups. SBP and DBP were continuously elevated, while men showed higher levels than women until their mid-60s; then, the trend was reversed. DBP in men became elevated from their 30s, reaching the highest in the 40s then slowly decreasing. DBP in women increased up to their 40s and 50s, then reached a plateau. PP increased rapidly from the 50s in both sexes. The major contributor of age-related BP elevation may be large artery stiffness in men, particularly from their 50s, while the blood pressure elevation of women may relate to diverse factors including large artery stiffness, stroke volume, and ventricular ejection rate. The rapid elevation of PP after the 50s in both men and women could represent a risk of cardiovascular or coronary mortality, particularly with increasing age. The current data showed a higher rate of hypertension in both sexes compared to previous reports. When those with both high-normal BP and hypertension are looked at in combination, BP management of the target population should be drastically elevated.

Prevalence of Dementia in the Elderly of an Urban Community in Korea (도시지역 노인들의 치매유병률에 관한 단면조사연구)

  • Na, Duk-L.;Yeon, Byeon-Gil;Kang, Yeon-Wook;Min, Kyung-Bok;Lee, Soo-Hyun;Lee, Sang-Suk;Lee, Mi-Ra;Pyo, Ok-Jung;Park, Chan-Byung;Kim, Sun-Mean;Bae, Sang-Soo;Kim, Dong-Hyun
    • Journal of Preventive Medicine and Public Health
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    • v.32 no.3
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    • pp.306-316
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    • 1999
  • Objectives: In Korea, as in most countries, there will be a sharp increase in the number of dementia patients in the near future. However basic data on dementia prevalence, which is important in defining epidemiologic characteristics and in implementing preventive strategy, are limited. This study was conducted to estimate the prevalence rate of dementia in the urban elderly aged 65 or older in Kwangmyung, Korea. Methods: A two phase design was used for case finding and case identification. In phase I, a representative sample aged 65 or older was selected and interviewed by door-to-door survey with a Korean version of the Mini-Mental State Examination (K-MMSE). In phase II, Of the 946 subjects interviewed in phase 1,356 elderly were randomly selected disproportionately according to K-MMSE score. Of these elderly, 223 (61.5%) underwent standardized clinical evaluations, including psychiatric interview, neurological examination, and neuropsychological assessment. Dementia was diagnosed by the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria. The diagnosis of Alzheimer's disease (AD) was made by National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and feinted Disorders Association(NINCDS-ADRDA) criteria and vascular dementia (VD) by DSM-IV. Results: The overall weighted prevalence rate of all dementia among Kwangmyung residents aged 65 or older was 12,8%(age-adjusted rate: 13,0%, 95% Confidence Interval[CI]: 10.6-15.3%). Women had much higher prevalence rate than men even when age was controlled(15.9%[95% CI 12.6-19.2%] vs 7.5%[95% CI 4.0-10.4%]), The rates of dementia were 5.2%, 12.2%, 17.0%, and 34.3% for the age groups of 65-69, 70-74, 75-79 and 80 and over, respectively. The rate of AD appeared to be slightly higher than that of VD(5.2% vs 4.8%), though not statistically significant. Most of the cases(69%) were mild dementia according to CDR(<1) in these subjects. Conclusions : These results showed that the prevalence rate of dementia among urban elderly in Korea appears to be higher than those of other Asian countries.

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Effects of Hypovolemic Hypotension on Cardiopulmonary Functions and Acid-Base Balance (출혈성 쇼크가 심폐기능 및 산.염기평형에 미치는 영향)

  • Sou, Won-Young;Lee, Sung-Haing
    • Journal of Chest Surgery
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    • v.6 no.2
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    • pp.131-142
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    • 1973
  • Studies of cardiopulmonary function and acid-base balance were performed on 29 dogs during control period, during oligemic hypotension and following return of blood to the animals. Intravenous morphine and local anesthesia were used. Fifteen of the 29 animals survived the complete experiment. The 14 animals that failed to survive the experimental period died between 15 to 90 minutes after the onset of bleeding. The results were as follows. 1. The heart rate increased after the onset of bleeding and failed to return to control level following reinfusion. Stroke volume decreased markedly after bleeding and failed to recover after return of blood from the reservoir. Cardiac output also decreased during oligemic hypotension and was maintained at this level after re-infusion. Total peripheral resistance decreased significantly immediately after bleeding, however it increased soon over the pre-bleeding level. Central venous pressure decreased after the onset of bleeding and remained at lower level for the rest of the experimental period. Arterial blood pressure, clown to 40-45 mmHg by acute hemorrhage, was elevated near to control level. Left ventricular work decreased tremendously during oligemic hypotension and failed to return to control level with the re-infusion of blood. Hematocrit value showed no significant decrease after bleeding and increased after re-infusion. Hemoglobin decreased after the onset of bleeding and recovered to control value after re-infusion. 2. The respiratory rate fell rapidly after bleeding from 124 to 29 and remained at this lower level for the remainder of the experiment. The tidal volume increased after bleeding and was maintained at this level for the remainder of the experiment. The respiratory minute volume showed no significant changes throughout the experimental period. Oxygen consumption fell lightly in all animals during oligemic hypotension and returned to normal levels following re-infusion. Arterial oxygen content and arterial oxygen saturation decreased following bleeding and the values returned to normal levels after the return of blood from the reservoir The arterio-venous oxygen difference increased after the onset of bleeding. It failed to return to normal values following re-infusion. Arterial $Pco_2$ decreased in all animals after the beginning of the bleeding. Partial pressure of $Co_2$ continued to fall until re-infusion, after which the values returned toward normal. Animals became acidotic. The pH fell to lower level following bleeding. Lactic acid and lactate: pyruvate ratio also increased during same period. Arterial pH and lactic acid failed to return to control value and lactate: pyruvate ratio increased more after re-infusion. Sodium bicarbonate decreased after bleeding and returned to control value following re-infusion.

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The Effect of Cooperative Learning on Academic Achievement in the Subject of 'Automobile Engine' in Technical High School (공업계 고등학교 '자동차기관'과목의 흡·배기 장치 정비 수업에서 협동학습이 학업 성취도에 미치는 효과)

  • Kim, Hern Gue;Lee, Sang Hyuk
    • 대한공업교육학회지
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    • v.32 no.1
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    • pp.33-54
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    • 2007
  • The purpose of this study was to verify the effects of cooperative learning on academic achievement of the maintenance of intake and exhaust stroke education in the technical high school. The following null hypotheses were stated and utilized for the purpose of the study. (1) Taxonomy of educational objectives(cognitive, affective and psychomotor domain) and (2) the level of entering behavior To verify the hypotheses of the study, 2 parts(17 students in each part) of the second grades from technical high school were selected. The data were collected and interpreted statistically by t-test using SPSS(ver. 10) at the .05 level of significance. The result of this study were as follows; First, learning together cooperative learning had little effect on the academic achievement in the cognitive domain but the affective and psychomotor domain were more effective than the traditional teaching method on the taxonomy of educational objectives. Second, learning together cooperative learning was effective on the academic achievements of lower and higher ability group of students, while wasn't effective on middle ability group in the level of entering behavior.

Semi-Quantitative Analyses of Hippocampal Heat Shock Protein-70 Expression Based on the Duration of Ischemia and the Volume of Cerebral Infarction in Mice

  • Choi, Jong-Il;Kim, Sang-Dae;Kim, Se-Hoon;Lim, Dong-Jun;Ha, Sung-Kon
    • Journal of Korean Neurosurgical Society
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    • v.55 no.6
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    • pp.307-312
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    • 2014
  • Objective : We investigated the expression of hippocampal heat shock protein 70 (HSP-70) infarction volume after different durations of experimental ischemic stroke in mice. Methods : Focal cerebral ischemia was induced in mice by occluding the middle cerebral artery with the modified intraluminal filament technique. Twenty-four hours after ischemia induction, both hippocampi were extracted for HSP-70 protein analyses. Slices from each hemisphere were stained with 2,3,5-triphenyltetrazolium chloride (2%), and infarction volumes were calculated. HSP-70 levels were evaluated using western blot and enzyme-linked immunosorbent assay (ELISA). HSP-70 subtype (hsp70.1, hspa1a, hspa1b) mRNA levels in the hippocampus were measured using reverse transcription-polymerase chain reaction (RT-PCR). Results : Cerebral infarctions were found ipsilateral to the occlusion in 10 mice exposed to transient ischemia (5 each in the 30-min and 60-min occlusion groups), whereas no focal infarctions were noted in any of the sham mice. The average infarct volumes of the 2 ischemic groups were $22.28{\pm}7.31mm^3$ [30-min group${\times}$standard deviation (SD)] and $38.06{\pm}9.53mm^3$ (60-min group${\times}$SD). Western blot analyses and ELISA showed that HSP-70 in hippocampal tissues increased in the infarction groups than in the sham group. However, differences in HSP-70 levels between the 2 infarction groups were statistically insignificant. Moreover, RT-PCR results demonstrated no relationship between the mRNA expression of HSP-70 subtypes and occlusion time or infarction volume. Conclusion : Our results indicated no significant difference in HSP-70 expression between the 30- and 60-min occlusion groups despite the statistical difference in infarction volumes. Furthermore, HSP-70 subtype mRNA expression was independent of both occlusion duration and cerebral infarction volume.

Effect of East-West pain treatment for Central Poststroke Pain on alleviation of pain and Rehabilitation (뇌졸중 후 중추성 통증 환자에 대한 동서협진이 진통과 재활에 미치는 영향)

  • Lee, Hyun-jong;Kim, Su-young;Lee, Sang-hoon;Seo, Dong-min;Lee, Doo-ik;Kim, Keun-sik;Lee, Jae-dong;Lee, Yun-ho;Yang, Hyung-in;Park, Jae-kyung;Choi, Do-young
    • Journal of Acupuncture Research
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    • v.20 no.2
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    • pp.42-49
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    • 2003
  • Purpose : In order to study the effectiveness of East-West pain treatment on central poststroke pain(CPSP), we evaluated its effect on alleviation of pain and rehabilitation of CPSP patients who were treated with eletroacupuncture and west pain treatment for four weeks. Methods : Twenty four patients diagnosed by their pain characteristics of central pain form stroke were treated with sympathetic nerve block, gabapentin, amitriptyline, and electroacupuncture for four weeks. Pain intensity through the visual analogue scale(VAS), and improvements of mobility and rehabilitation through the modified Barthel index(MBI) and Rankin scale(RS), respectively, before and after pain treatment were also assessed. Results : VAS pain scores were significantly improved from $7.7{\pm}1.7$ to $4.4{\pm}2.0$ with pain treatment(p<0.05). In accordance with improvement of ain scores, RS and MBI scores ere also improved from $2.88{\pm}0.95$ to $2.13{\pm}1.01$ and from $83.0{\pm}16.9$ to $94.7{\pm}9.5$(p<0.05), respectively, with pain treatment(p<0.05). Conclusions : It was suggested that the active pain treatment was contributed to the rehabilitation of CPSP patients, resulting in improvement of quality of life of CPSP patients. Futhermore, East pain treatment in combination with West pain treatment may be useful modality to alleviate CPSP.

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