• Title/Summary/Keyword: fibrillation

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Analysis of Effects of Fiber's Collapse Index on Physical Properties of Paper Using CLSM (종이의 물리적 특성에 미치는 섬유의 찌그러짐 특성의 영향에 대한 CLSM 분석)

  • 김서환;박종문;김철환
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.31 no.1
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    • pp.46-51
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    • 1999
  • The most important effect of refining is believed as the internal fibrillation. The internal fibrillation is the separation of the fiber wall into several lamellae. The internal fibrillation results in fiber swelling as water penetrates the fiber wall. The increase in paper strength as a result of refining was due to delamination which made the fiber more flexible. Pulp fibers are refined to 20, 40, and 70$^{\circ}$SR freeness at Valley beater. Changes of Physical paper properties are analyzed depending on fiber wall thickness and fiber's collapse index at 2.5 and 5.6kg$_f$ refining load. At same $^[\circ}$SR freeness with 2.5kg$_f$ refining load, fiber wall thickness is increased further than at high 5.6kg$_f$ refining load. With higher fiber wall thickness by lower intensity refining load, higher internal fibrillation, flexibility, collapsability of fibers are achieved. Those effects improve WRV, tensile strength, and burst strength. Tear strength shows opposite trend to tensile and burst strength as usual.

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Swelling and Fibrillation of Lyocell Fibers in Water and NaOH Solution (Lyocell 섬유소재의 알칼리 팽윤과 피브릴화 거동)

  • Min, Byung-Ghyl;Jeong, Young-Jin;Kim, Chang-Whan;Oh, Young-Sae
    • Fashion & Textile Research Journal
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    • v.1 no.1
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    • pp.56-61
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    • 1999
  • Swelling and fibrillation of two kinds of lyocell, $Tencel^{(R)}$ and $Lyocell^{(R)}$, were investigated using polarizing and scanning electron microscope (SEM). $Tencel^{(R)}$ of a representative lyocell showed that loop tenacity which is related to wrinkle and resilience of fiber does not show significant reduction in wet state. Two kinds of lyocell exhibited surprising degree of swelling in aqueous NaOH solution under free tension. Diameters of $Tencel^{(R)}$ and $Lyocell^{(R)}$ swelled up to 670% and 830%, respectively in the range of around 10% NaOH concentration. Molecular orientation estimated by birefringence also reduced remarkably in alkaline solution. Moreover, diameter and birefringence which changed in alkaline solution did not recovered to original level even after washing and drying. Fibrillation of $Lyocell^{(R)}$ fiber observed by SEM seems to be easier than that of $Tencel^{(R)}$. In order to understand the difference between $Tencel^{(R)}$ and $LyoceJl^{(R)}$, further study on the structure of the two fibers will be followed.

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Case Report of Chengsim Yeunja-tang (CYT) for Atrial Fibrillation with cerebral-infarction. (청심연자탕으로 호전된 뇌경색을 동반한 심방세동 환자 치험 3례)

  • Kim, Jung-Chul;Oh, Sung-Won;Song, Chang-Hoon;Lee, Seul-hee;Jeong, Jong-Jin;Kim, Jong-Yun;Sun, Seung-Ho
    • The Journal of Internal Korean Medicine
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    • v.27 no.3
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    • pp.751-761
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    • 2006
  • Atrial fibrillation (AF) is a common arrhythmia that is a potent independent risk factor for stroke. The incidence of AF increases with age and most affected people have underlying cardiac disease. An aging society increases the incidence of AF patients. The case was designed to evaluate the improving effect of Chengsim Yeunja-tang (CYT) for atrial fibrillation (AF) with Cb-infarction patients. This patient was treated with CYT and had significant improvement in symptoms and change of EKG. -Heart rate decreased in patients with higher than normal heart rate -RV5+SV1 voltage decreased (LVH improved) -Arrhythmia remained steady. -Palpitation. chest discomfort, dyspnea, headache, dizziness diminished. Results suggest that CYT is an effective treatment for Taeumin AF patients.

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Extracting Fuzzy Rules for Classifying Ventricular Tachycardia/Ventricular Fibrillation Based on NEWFM (심실빈맥/심실세동 분류를 위한 NEWFM 기반의 퍼지규칙 추출)

  • Shin, Dong-Kun;Lee, Sang-Hong;Lim, Joon-S.
    • Journal of Internet Computing and Services
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    • v.10 no.2
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    • pp.179-186
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    • 2009
  • This paper presents an approach to classify normal and Ventricular Tachycardia/Ventricular Fibrillation(VT/VF) from the Creighton University Ventricular Tachyarrhythmia DataBase(CUDB) using the neural network with weighted fuzzy membership functions(NEWFM). In the first step, wavelet transform is used for producing input values which are used in the next step. In the second step, two numbers of input features are extracted by phase space reconstruction method and peak extraction method using coefficients produced by wavelet transform in the previous step. NEWFM classifies normal and VT/VF beats using two numbers of input features, and then the accuracy rate is 90.13%.

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Testing the Mediating Effect of Appraisal in the Model of Uncertainty in Illness

  • Kang, Younhee
    • Journal of Korean Academy of Nursing
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    • v.33 no.8
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    • pp.1127-1134
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    • 2003
  • Background. Although there have been a great number of research studies based on the model of uncertainty in illness, few studies have considered the appraisal portion of model. Purpose. The purpose of this study was to test the mediating effect of appraisal in the model of uncertainty in illness. Additionally, this study aimed to examine the relationships among uncertainty, symptom severity, appraisal, and anxiety in patients newly diagnosed with atrial fibrillation. Methods. This study employed a descriptive correlational and cross-sectional survey design using a face-to-face interview method. Patients diagnosed with atrial fibrillation within the previous 6 months prior to data collection were interviewed by Mishel Uncertainty in Illness Scale-Community Form, appraisal scale, Symptom Checklist-Severity V.3, and State Anxiety Inventory. Results. A total of 81 patients with atrial fibrillation were recruited from two large urban medical centers in Cleveland, Ohio, U.S.A.. Symptom severity was the significant variable in explaining uncertainty ($\beta$=0.34). Individuals with greater symptom severity perceived more uncertainty. Uncertainty was appraised as a danger rather than opportunity, and those with greater uncertainty appraised a greater danger (p<.0l). While the appraisal of opportunity had the negative relationship with anxiety (r=-0.25), the appraisal of danger was positively associated with anxiety (r=0.78). The measure of goodness of fit (Q) of the model was .7863, and the significant test (X$^2$) for the Q was statistically significant (df =3, p<.00l). Accordingly, the overall mediating model of uncertainty in illness was proven not to be fit to the empirical data of patients with atrial fibrillation. Consequently, the mediating effect of appraisal was not supported by the empirical data of this study. Conclusion. The findings of this study were discussed in terms of their relevance compared with those of previous studies or theoretical framework and the plausible explanations on study findings. Lastly, in order to expand the present body of knowledge on uncertainty in illness model, recommendations for the future nursing studies were included.

Inhibition of $A{\beta}42$ Fibrillation and Toxicity with ${\beta}$-Asarone ($A{\beta}42$의 섬유화 및 독성에 대한 ${\beta}$-Asarone의 저해 효과)

  • Kim, Jia;Lee, Chul Won;Lee, Boo Kyun;Lee, Jang Cheon;An, Won Gun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.28 no.3
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    • pp.317-321
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    • 2014
  • Amyloid-${\beta}$ protein ($A{\beta}$) is a pathological component of Alzheimer's disease (AD) by participating in the senile plaque formation in the patient's brain. Although the exact mechanism of $A{\beta}$ toxicity is not fully elucidated, it is considered to be closely related to its fibrillation process. For prevention of AD, recent studies have suggested various small molecules which inhibit $A{\beta}$ fibrillation. In this report, ${\beta}$-asarone found in acorus plant has been investigated as an anti-amyloid molecule. ${\beta}$-Asarone was demonstrated to prevent in vitro fibrillation of $A{\beta}$ by inducing the oligomer formation that obviously decreased cytotoxicity. Therefore, ${\beta}$-asarone could be suggested as an inhibitory agent of $A{\beta}$ fibrillation and toxicity, which would help us not only to understand underlying principle of amyloidogenesis mechanism but also to develop a controlling strategy toward AD.

Dyeing Properties Resin Treatment Effects of the Lyocell Fabrics (리오셀 직물 수지가공 효과와 염색성)

  • Yoo, Hye-Ja;Lee, Hye-Ja
    • Journal of the Korean Society of Clothing and Textiles
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    • v.32 no.7
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    • pp.1095-1103
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    • 2008
  • The effects of resin finish and dyeabilities of four kinds of Iyocell fabrics that were manufactured by four kinds of pulps were investigated. The dyeabilities of Iyocell fabrics were similar, but differed from cotton fabric. In early stage of 30 minutes, cotton fabric was shown higher dye exhaustion ratio than Iyocell fabrics, however after then cotton fabric did not increase dye exhaustion, Iyocell fabrics increased continuously. At last, the dye exhaustion ratio of Iyocell fabrics were about 75% and that of cotton fabric was 65%. Two kinds of experimental procedures were applied for Iyocell fabrics. One was what the fabrics were treated with resins and washed with cellulase, and then dyed with reactive dyes. The other procedure was the fabrics were dyed with reactive dyes, and then applied the resin treatments and cellulase washing. After fibrillation and washing the undyed Iyocell fabric and the Iyocell fabric that was dyed with C.I.Reactive Red 120, their weight loss ratios were 3.5% and 2.8%, respectively. Dyeing with reactive dyes caused the crosslinking between cellulose and dyes and the crosslinking decreased fibrillation. The weight loss by enzyme washing of Iyocell fabrics decreased by the glyoxal and melamine resin treatments. The reduction of weight loss can be caused by fibrillation decrease. Dyeing and resin treating can be showed the synergic effect on the reduction of fibrillation. The effect of glyoxal resin on the reduction of fibrillation was a little better than that of melamine resin.

Self-care in Patients with Atrial Fibrillation Based on the Theory of Unpleasant Symptoms (불쾌 증상 이론을 적용한 심방 세동 환자의 자가관리)

  • Kim, Min Young;Lee, Sun Hee;Park, Han Jong
    • Journal of Korean Clinical Nursing Research
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    • v.28 no.1
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    • pp.23-33
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    • 2022
  • Purpose: This study aimed to identify the relationships among disease severity, anxiety, depression, social support, unpleasant symptoms and self-care among patients with atrial fibrillation based on the unpleasant symptom theory, and to examine the mediating effects of unpleasant symptoms. Methods: A cross-sectional study was conducted. The participants were 216 patients with atrial fibrillation who were being followed up on an outpatient basis at a university hospital in Seoul. Data were collected from November 1, 2020 to June 30, 2021, using self-report questionnaires. Data were analyzed using IBM SPSS/WIN 27.0 and PROCESS macro with 95% bias-corrected bootstrap confidence interval(CI). Results: The average age of participants in this study was 66.0years. Disease severity (β=10.19, p<.001) and depression (β=1.53, p<.001) had significant positive relationships with unpleasant symptoms. Also, unpleasant symptoms (β=-0.03, p=.006) had a negative relationship with physical activity, which is a subscale of self- care. Social support (β=0.06, p<.001) was positively related with physical activity. Unpleasant symptoms showed a mediation effect in the relationship between disease severity and physical activity (Bias corrected bootstrap CI -0.65, -0.04). Depression had an indirect effect on physical activity that was mediated by unpleasant symptoms (Bias corrected bootstrap CI -0.11, -0.00). Conclusion: The findings of this study suggest that integrated strategies including physical, psychological, and social factors should be considered to promote self-care in patients with atrial fibrillation.

Risk Factors of Atrial Fibrillation after Coronary Artery Bypass Grafting (관상동맥우회술 후 발생하는 심방 세동에 대한 분석)

  • Hwang, Yeo-Ju;Park, Chul-Hyun;Jeon, Yang-Bin;Choi, Chang-Hyu;Lee, Jae-Ik;Park, Kook-Yang
    • Journal of Chest Surgery
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    • v.40 no.2 s.271
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    • pp.90-96
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    • 2007
  • Background: Postoperative atrial fibrillation is the most frequently arrhythmic complication associated with coronary artery bypass graft surgery. This study was designed to investigate the incidence of atrial fibrillation in patients undergoing OPCAB and on-pump CABG and to identify the risk factors associated with its development. Material and Method: 247 consecutive patients were evaluated among 306 patients who underwent the coronary artery bypass graft surgery between January, 2002 and December, 2005. 178 patients underwent OPCAB (OPCAB group) and 69 patients underwent On-pump CABG (On-pump CABG group). The incidence and the risk factors of atrial fibrillation in two groups were determined. Result: There were no significant differences between two groups with respect to the preoperative demographic characteristics of the patients. The incidences of postoperative atrial fibrillation were 25 cases (14%) in OPCAB group and 15 cases (21%) in On-pump CABG group. Age over 65 years, net positive fluid imbalance for postoperative 3 days, and chest tube bleeding for postoperative 3 days were independent predictive factors in OPCAB group. Age over 65 years and net positive fluid imbalance for postoperative 3 days were independent predictive factors in On-pump CABG group. In multivariate analysis, age over 65 years was the only risk factor of postoperative atrial fibrillation in both groups. Conclusion: Atrial fibrillation is a common complication after procedures of myocardial revascularization. There wasn't a low incidence of postoperative atrial fibrillation in OPCAB, compared with On-pump CABG. Age over 65 years was associated with postoperative atrial fibrillation irrespective of the use of cardiopulmonary bypass.

Effect of Mechanical Impact Treatment on Fiber Morphology and Handsheet Properties

  • Yung B. Seo;Kim, Dukki;Lee, Jong-Hoon;Yang Jeon
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2001.11a
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    • pp.183-199
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    • 2001
  • Alternative way of shaping fibers suitable for papermaking was introduced. Impact refining, which was done simply by hitting wet fibers with a metal weight vertically, was intended to keep the fibers from shortening and to cause mostly internal fibrillation. Virgin chemical pulp, its recycled one and OCC were used in the experiment. It was noticed from the experiment that impact refining on virgin chemical pulp kept the fiber length and Increased bonding properties greatly, However, in the recycled fibers from the chemical pulp, fiber length and bonding properties were decreased. In OCC, which seems to contain fractions of semi-chemical pulp and mechanical pulp (GP), and which is recycled pulp from corrugated boxes, fiber length and bonding properties were decreased disastrously. We believe recycled cellulosic fibers (recycled chemical pulp and OCC in this case), which went through hornification, were less resistant to the mechanical impact than virgin chemical pulp. For virgin chemical pulp, impact refining allowed no significant fiber length shortening, high WRV, and high mechanical strength.

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