4,313 research outputs found

    Effects of Creatine Monohydrate Supplementation on Cytochrome C and Caspase-9 Expression in Skeletal Muscles from Doxorubicin Treated Rats

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    Doxorubicin (DOX) is an effective chemotherapeutic drug for many types of cancer. However, the deleterious effect of DOX is also observed in heart and skeletal muscles. Doxorubicin-induced reactive oxygen species (ROS) in mitochondria causes muscle dysfunction and atrophy leading to the release of cytochrome c (cyt c) and activation of caspase-9 (casp-9) which cause apoptosis, a programmed cell death in skeletal muscles. Previous studies have proposed that creatine (Cr) possesses antioxidant capacity by reducing ROS in oxidative environment. Creatine supplements have shown to reduce mitochondrial ROS production and decrease apoptotic enzyme activities in oxidative skeletal muscles; however, Cr’s effects on DOX-induced apoptosis are not yet fully understood. PURPOSE: To investigate the effects of two different Cr supplementation protocols on cyt c and casp-9 expression in skeletal muscles from rats treated with DOX at two different time points. METHODS: Male Sprague Dawley rats (n=120) were randomly assigned to one of the three different diet treatments: control (CON, n=40), 2% Cr for four-week (2% Cr, n=40), and the Cr loading consisting of 4% Cr for one-week followed by three-week of 2% Cr (4% Cr, n=40). Then, each group was randomly assigned to two different time points for the drug administration: one-day prior to the sacrifice (1, n=20) and three-day prior to the sacrifice (3, n=20). Lastly, each group was randomly assigned to two different drug treatments: 3 mL of saline (SAL, n=10) and 15 mg/kg of DOX (DOX, n=10). The left soleus (SOL) and left extensor digitorum longus (EDL) were collected after anesthesia and homogenized. A western blot assay was used to determine protein expression of cyt c and casp-9. RESULTS: No significant effects of Cr supplementation and DOX administration on cyt c and casp-9 expressions were observed in both the SOL and EDL (p\u3e0.05). The interaction between the Cr supplementation and the DOX injection was also not significant (p\u3e0.05). A trend toward a decrease in cyt c and casp-9 expression was observed in the 4% Cr group of 3 SOL and 1-EDL with the DOX injection, but there were no significant differences (p\u3e0.05). CONCLUSIONS: Even though there were no significant main effects of Cr diet treatment, DOX administration and no interactions, a potential trend indicated that the Cr loading protocol may prevent apoptosis by attenuating the expressions of cyt c and casp-9 in skeletal muscles. Further research with measuring oxidative stress level, protein synthesis and degradation, and amount of Cr supplementation consumed needs to be conducted in order to fully understand the mechanism of the Cr supplement and the DOX administrations in skeletal muscles

    Asian monetary cooperation

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    Thesis(Master) --KDI School:Master of International Relations and Political Economy,2001CHAPTER I. INTRODUCTION CHAPTER II. HISTORY OF ASIAN MONETARY COOPERATION CHAPTER III. ECONOMIC RATIONALE FOR ASIAN MONETARY COOPERATION CHAPTER IV. Political Aspects of the Asian Monetary Cooperation CHAPTER V. CONCLUSIONmasterpublishedby Kim Hee-Yeon

    Bifurcations in nonlinear Schrödinger equations with double well potentials

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    In this thesis, we consider nonlinear Schrödinger equations with double well potentials with attractive and repelling nonlinearities. We discuss bifurcations along bound states, especially ground states and the first excited states, and also deal with orbital stability of the ground states. In attractive case with large separations for double wells, our results shows that the ground state must undergo the secondary symmetry breaking bifurcation, while the first excited states can be uniquely extended as long as the bifurcation of the ground state has not occurred. In repelling case with large separations for double wells, we prove that the secondary bifurcation of the ground state does not emerge, even in the strongly nonlinear regime, while the first excited state must undergo the secondary bifurcation on the first excited states

    Association of serum adipocytokine levels with cardiac autonomic neuropathy in type 2 diabetic patients

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    <p>Abstract</p> <p>Background</p> <p>Cardiac autonomic neuropathy (CAN) is a common complication of diabetes associated with poor prognosis. In addition, the autonomic imbalance is associated with cardiovascular disease (CVD) in diabetes. It is thought that adipocytokines contribute to the increased risk of vascular complications in patients with type 2 diabetes mellitus (T2DM). However, literature data on the association between CAN with adipocytokines such as leptin, tumor necrosis factor-alpha (TNF-alpha), adiponectin in subjects with T2DM is limited.</p> <p>Therefore, in the present study, we examined the relationship between fasting serum leptin, TNF- alpha and adiponectin and CAN in Korean T2DM patients.</p> <p>Methods</p> <p>A total of 142 T2DM patients (94 males, 48 females) were recruited. CAN was assessed by the five tests according to the Ewing's protocol and the time and frequency domain of the heart rate variability (HRV) was evaluated. Serum TNF-alpha and adiponectin levels were measured using enzyme-linked immunosorbent assay and serum leptin levels were measured using radioimmunoassay.</p> <p>Results</p> <p>Although, the mean levels of leptin, TNF-alpha and adiponectin were not significantly different between the groups with and without CAN, the levels of leptin and adiponectin had a tendency to increase as the score of CAN increased (p = 0.05, p = 0.036). Serum leptin levels demonstrated a negative correlation with low frequency (LF) in the upright position (p = 0.037). Regarding TNF-alpha, a significant negative correlation was observed with SDNN and RMSSD in the upright position (p = 0.023, p = 0.019). Adiponectin levels were not related to any HRV parameters. Multivariate logistic regression analysis demonstrated that the odds of CAN increased with a longer duration of diabetes (1.25, [1.07-1.47]) and higher homeostatic model of assessment-insulin resistance (HOMA-IR) (5.47, [1.8-16.5]). The relative risks for the presence of CAN were 14.1 and 51.6 for the adiponectin 2<sup>nd</sup>, 3<sup>rd </sup>tertiles when compared with first tertile (p-value for trend = 0.022).</p> <p>Conclusions</p> <p>In the present study, the higher serum adiponectin levels and HOMA-IR were associated with an increased risk for the presence of CAN. Also, the CAN score correlated with the serum adiponectin. Serum adipocytokines such as leptin and TNF-alpha were significantly correlated with parameters of HRV, representative markers of CAN. Future prospective studies with larger number of patients are required to establish a direct relationship between plasma adipocytokine concentrations and the development or severity of CAN.</p

    Development of A New Coating System for The High Functional Mold in Thin-wall Casting

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    A new inorganic binder system has been developed to prepare the mold having a high strength for the thin-walled casting. To increase the fracture strength at high temperature, a large amount of inorganic binder should be converted into glass phase and the generated glass phase has to be homogeneously coated on the surface of starting particles. In this work, two types of process were employed to investigate the coating and glassification efficiencies of inorganic precursor. In the first process (process I), the green body consisting of starting powder and organic binder was dipped in the inorganic precursor solution. In the second process (process II), the starting powder was coated by inorganic precursor, and then the organic binder was used to form the green body. The mold sample prepared using process II showed the higher strength value than that using process I, owing to the inclement effect on the glassfication efficiency by the loss of inorganic precursor in process I. The prepared real mold was perfectly produced and the casted product showed a clean surface without defects such as dross, nonmetallic inclusions, and crack. Consequently, the new inorganic binder system could be applied for preparing the mold for the thin-wall casting having high mechanical properties

    Structural Optimization of a Knuckle with Consideration of Stiffness and Durability Requirements

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    The automobile’s knuckle is connected to the parts of the steering system and the suspension system and it is used for adjusting the direction of a rotation through its attachment to the wheel. This study changes the existing material made of GCD45 to Al6082M and recommends the lightweight design of the knuckle as the optimal design technique to be installed in small cars. Six shape design variables were selected for the optimization of the knuckle and the criteria relevant to stiffness and durability were considered as the design requirements during the optimization process. The metamodel-based optimization method that uses the kriging interpolation method as the optimization technique was applied. The result shows that all constraints for stiffness and durability are satisfied using A16082M, while reducing the weight of the knuckle by 60% compared to that of the existing GCD450

    A STUDY ON USERS’ AWARENESS OF MOVING-PICTURE ADS IN MOVINF-PICTURE CONTENTS WITH DIFFERENT ONLINE MEDIA CHARATERISTICS

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    Internet plays an important role in our lives and the number of internet users keeps increasing. As internet users are exposed to ads from online media while not knowing, advertising market’s interest in moving-picture ads increases. Thus, this study comparatively measured effects of moving-picture ads inserted in news-related moving-picture contents of media companies and those of moving-picture ads inserted in moving-picture contents of professional moving-picture UCC. Advertising effects were compared between media characteristics (news and UCC) and keyword relatedness (related or unrelated keyword) and interactions of the two factors were measured. As a result, there was a significant difference in media characteristics and keyword relatedness. As for media characteristics, advertising effects of news-related moving pictures were higher than those of professional moving-picture UCC in all items. As for keyword relatedness, executing ads of keyword related to moving-picture contents was verified to have higher advertising effects than executing ads of unrelated keywords. There was no significant difference in interactions between these two factors. As interest in the moving picture advertising market increases, the necessity to introduce a method to analyze effects of moving-picture ads is raised. As for evaluation of advertising effects of moving pictures of media companies, the theme to be dealt in this paper, it is still difficult to state that moving-picture ads are facilitated in the overall market of moving picture services. So under such circumstances that verification is hard to achieve, the attempt of this study is considered to be meaningful. Keyword: media companies, UCC, moving-picture contents, moving-picture ads, advertising effects, media, new

    Differential associations of central and brachial blood pressure with carotid atherosclerosis and microvascular complications in patients with type 2 diabetes

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    BACKGROUND: We examined the relationship between central blood pressure (BP), brachial BP with carotid atherosclerosis and microvascular complications in type 2 diabetes mellitus (T2DM). METHODS: We recruited 201 patients who were evaluated for central BP, brachial BP, carotid ultrasonography, brachial-ankle pulse wave velocity (baPWV), ankle-brachial index (ABI) and microvascular complications. Central BP were calculated using a radial automated tonometric system. RESULTS: Agreement between central BP and brachial BP was very strong (concordance correlation coefficient between central and brachial SBP = 0.889, between central and brachial PP = 0.816). Central pulse pressure (PP) was correlated with mean carotid intima-media thickness (CIMT), baPWV and ABI, whereas brachial PP was borderline significantly correlated with CIMT. The prevalence of nephropathy(DN) and retinopathy(DR) according to the brachial PP tertiles increased, the prevalences of microvascular complications were not different across central PP tertiles. In multivariate analysis, the relative risks (RRs) for the presence of DR were 1.2 and 4.6 for the brachial PP tertiles 2 and 3 when compared with the first tertile. Also, the RRs for the presence of DN were 1.02 and 3 for the brachial PP tertiles 2 and 3 when compared with the first tertile. CONCLUSIONS: Agreement of central BP and brachial BP was very strong. Nonetheless, this study showed that higher brachial PP levels are associated with increased probability for the presence of microvascular complications such as DR/DN. However, there are no associations with central SBP and central PP with microvascular complications. Central BP levels than brachial BP are correlated with surrogate marker of macrovascular complications
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