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Hwaseong, South Korea

Kim J.-H.,Chosun University | Yoo S.-J.,Seonam University | Kwak D.-H.,Seonam University | Jung H.-J.,Shingyeong University | And 3 more authors.
Nanoscale Research Letters

Alumina nanofibers were prepared by a technique that combined the sol-gel and electrospinning methods. The solution to be electrospun was prepared by mixing aluminum isopropoxide (AIP) in ethanol, which was then refluxed in the presence of an acid catalyst and polyvinylpyrolidone (PVP) in ethanol. The characterization results showed that alumina nanofibers with diameters in the range of 102 to 378 nm were successfully prepared. On the basis of the results of the XRD and FT-IR, the alumina nanofibers calcined at 1,100°C were identified as comprising the α-alumina phase, and a series of phase transitions such as boehmite → γ-alumina → α-alumina were observed from 500°C to 1,200°C. The pore size of the obtained γ-alumina nanofibers is approximately 8 nm, and it means that they are mesoporous materials. The kinetic study demonstrated that MO adsorption on alumina nanofibers can be seen that the pseudo-second-order kinetic model fits better than the pseudo-first-order kinetic model. © 2014 Kim et al. Source

Bagalkot T.R.,Chonbuk National University | Park J.-I.,Chonbuk National University | Kim H.-T.,Maeumsarang Hospital In san Medical Foundation | Kim H.-M.,Maeumsarang Hospital In san Medical Foundation | And 5 more authors.
Psychiatry (New York)

Objectives: Our study evaluated the lifetime prevalence of and risk factors for suicidal ideation and suicide attempts in Jeollabuk-do Province, Korea. Method: Participants were selected from the population of individuals aged 13-100 years living Jeollabuk-do Province, Korea. A total of 2,964 subjects provided information about lifetime suicidal behavior and sociodemographic and psychological characteristics, completing the Zung Depression Scale, the Scale for Suicidal Ideation, the Multidimensional Anger Inventory, and the Rosenberg Self-Esteem Scale. Results: The lifetime prevalence of suicidal ideation and suicide attempts, 24.8% and 6.2%, respectively, were higher than in previous studies. Multivariate regression revealed that family harmony had the highest odds ratio of all variables, including psychological factors. Along with depression and self-esteem, anger— which is the basic symptom of the Korean culture-related anger syndrome, Hwa-byung—was significantly associated with lifetime suicidal behavior. Conclusions: Lifetime suicidal behavior was highly prevalent in Jeollabuk-do Province. The most significant risk factors were found to be social support, family disharmony, anger, depression, and low self-esteem in Koreans. © 2014 Washington School of Psychiatry. Source

Kim S.H.,Kangwon National University | Cho Y.-R.,Dankook University | Kim H.-J.,Dankook University | Oh J.S.,Dankook University | And 8 more authors.

In cancer, VEGF-induced increase in vascular permeability results in increased interstitial pressure, reducing perfusion and increasing hypoxia, which reduce delivery of chemotherapeutic agents and increase resistance to ionizing radiation. Here, we show that both TIMP-2 and Ala + TIMP-2, a TIMP-2 mutant without matrix metalloproteinase inhibitory activity, antagonize the VEGF-A-induced increase in vascular permeability, both in vitro and in vivo. Like other agents known to preserve endothelial barrier function, TIMP-2 elevates cytosolic levels of cAMP and increases cytoskeletal-associated vascular endothelial cadherin in human microvascular endothelial cells. All of these effects are completely ablated by selective knockdown of integrin α3β1 expression, expression of a dominant negative protein tyrosine phosphatase Shp-1 mutant, administration of the protein tyrosine phosphatase inhibitor orthovanadate, or the adenylate cyclase inhibitor SQ22536. This TIMP-2-mediated inhibition of vascular permeability involves an integrin α3β1-Shp-1-cAMP/protein kinase A-dependent vascular endothelial cadherin cytoskeletal association, as evidenced by using siRNAs to integrin α3β1 and Shp-1, or treatment with Shp-1 inhibitor NSC87877 and protein kinase A inhibitor H89. Our results demonstrate the potential utility for TIMP-2 in cancer therapy through "normalization" of vascular permeability in addition to previously described antiangiogenic effects. © 2012 by The American Society of Hematology. Source

Park J.-I.,Chonbuk National University | Han M.-I.,Maeumsarang Hospital | Kim M.S.,Jeonju University | Yoon M.-S.,Chonbuk National University | And 3 more authors.
International Journal of Geriatric Psychiatry

Objectives Despite the importance of tending to older individuals who are vulnerable to suicide, little is known about suicidal ideation in the portion of this population receiving home-care services in Asian countries. The objective of this cross-sectional study was to examine predictors of suicidal ideation in older individuals using home-care service. Method Participants were randomly selected from the individuals 50 years old and over using home-care services across Jeollabuk-do Province, Korea. A total of 697 subjects participated in this study. Each participant completed the short version of the Geriatric Depression Scale, the Scale for Suicidal Ideation, the Multidimensional Scale of Perceived Social Support, and the World Health Organization Disability Assessment Schedule II. Results Hierarchical regression analyses revealed that depression, perceived social support, and disability were significant predictors of suicidal ideation, whereas the roles of subjective health status and fish consumption remained ambiguous in this regard. In terms of social support, we also found that less perceived social support from family members was related to higher levels of suicidal ideation. The associations between various categories of disability and suicidal ideation disappeared after controlling for depression. Our investigation of the mediating effect of depression on the relationship between disability and suicidal ideation revealed that depression was either a complete (disability related to cognition, self-care, getting along with others, and life activities) or partial (disability related to participation) mediator. Conclusions Preventive strategies focusing on depression, social support, and disability should be emphasized during encounters with older people receiving home-care services. © 2013 John Wiley & Sons, Ltd. Source

Lee S.-J.,U.S. National Cancer Institute | Lee S.-J.,Shingyeong University | Tsang P.S.,U.S. National Cancer Institute | M Diaz T.,U.S. National Cancer Institute | And 2 more authors.
Laboratory Investigation

In this study, we examine the effects of tissue inhibitor of metalloproteinases-2 (TIMP-2) on the phosphorylation status of specific phosphotyrosine residues on the vascular endothelial cell growth factor receptor-2 (VEGFR-2) cytoplasmic tail and examine the effects on associated downstream signaling pathways. To focus on metalloproteinase-independent mechanisms, we used the TIMP-2 analog known as AlaTIMP-2 that is deficient in matrix metalloproteinase-inhibitory activity. Our experiments are designed to compare the effects of VEGF-A stimulation with or without AlaTIMP-2 pretreatment, as well as basal responses in human microvascular endothelial cells. Our results show that AlaTIMP-2 selectively alters the phosphorylation pattern of VEGFR-2 after VEGF-A stimulation and disrupts the downstream activation of PLC-γ, Ca 2 flux, Akt, and eNOS, as well as decreasing cGMP levels. Moreover, we observed an AlaTIMP-2-induced reduction in cGMP levels typically elevated by exogenous NO donors implicating AlaTIMP-2 in the direct activation of an isobutylmethylxanthine (IBMX)-sensitive cGMP phosphodiesterase activity. TIMP-2 suppression of endothelial mitogenesis and angiogenesis involves at least two mechanisms, one mediated by protein tyrosine phosphatase inhibition of VEGFR-2 activation as well as downstream signaling and a second mechanism involving direct activation of an IBMX-sensitive phosphodiesterase activity. © 2010 USCAP, Inc All rights reserved. Source

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