• Journal of Yeungnam Medical Science
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• v.17 no.1
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• pp.1-11
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• 2000

Inhibition of cyclooxygenase(COX), and thus prevention of the formation of prostaglandins, provided a unifying explanation of the therapeutic and toxic actions of nonsteroidal anti-inflammatory drugs (NSAIDs). Recently, the discovery of the two isoforms of COX was made by molecular biologists studying neoplastic transformation in chick embryo cells. The constitutive enzyme, COX-1, is obviously responsible for the production of prostaglandins involved in housekeeping functions such as maintenance of integrity of the gastric mucosa, renal blood flow and platelet aggregation. The inducible form of COX (COX-2) is responsible for the formation of prostaglandins that pathologically affects inflammation, pain and fever. Clearly, all the experimental and clinical data support the hypothesis that the beneficial effects of NSAIDs are due to inhibition of the COX-2 enzyme, whereas the gastrotoxicity is due to inhibition of COX-1. The cox-2/COX-1 ratios of the NSAIDs in common use have been measured and compared with epidemiological data on their side effects. There is little evidence to suggest that one NSAID is clearly more effective than another, But substantial individual variability is present with respect to the pharmacology and pharmacokinetics of these drugs: therefore it is essential to adjust the dosage and choose specific drug to the patient's response.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.2
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• pp.217-224
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• 2009

This study aims to show the guideline to select optimal anti-vibration gloves for specific power tools to prevent hazardous vibration to human body. It is most desirable for the correct evaluation of handtransmitted vibration form the power tool handle to measure the acceleration between the handle surface and the hand palm as recommended in ISO 5349-1. First, the accurate acceleration measurement device was developed of which the thickness and weight were less than 6 mm and 12 g respectively so that it can be placed between the handle and the palm without any inconvenience during the measurement. Finally, using the device we estimated anti-vibration glove performances considering the frequency characteristics of generated vibration by the power tool.

• Corrosion Science and Technology
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• v.20 no.1
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• pp.7-14
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• 2021

PosMAC^® is a brand of Zn-Mg-Al hot-dip coated steel sheet developed by POSCO. PosMAC^® can form dense surface oxides in corrosive environments, providing advanced corrosion resistance compared to traditional Zn coatings such as GI and GA. PosMAC^® 3.0 is available for construction and solar energy systems in severe outdoor environments. PosMAC^®1.5 has better surface quality. It is suitable for automotive and home appliances. Compared to GI and GA, PosMAC^® shows significantly less weight reduction due to corrosion, even with a lower coating thickness. Thin coating of PosMAC^® provides advanced quality and productivity in arc welding applications due to its less generation of Zn fume and spatters. In repeated friction tests, PosMAC^® showed lower surface friction coefficient than conventional coatings such as GA, GI, and lubricant film coated GA. Industrial demand for PosMAC^® steel is expected to increase in the near future due to benefits of anti-corrosion and robust application performance of PosMAC^® steel.

• The Korea Journal of Herbology
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• v.29 no.1
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• pp.1-6
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• 2014

Objectives : Many of currently used anti-cancer drugs were developed to target cell death mechanisms and had serious side effects by causing damage to normal cells. Hangambujeongsan or Kangai Fuzheng Powder was a mixture based on the traditional Chinese medicine. It had been used in the local Chinese hospitals to treat cancer patients for decades and had shown a certain level of beneficial effects without major toxic effects. But its mechanism of action had not been elucidated yet. Thus this study aimed to investigate the effects of Kangai Fuzheng Powder in an in vitro experiment. Methods : Cancer lines or RAW264.7 mouse macrophage cells were treated with Kangai Fuzheng Powder. Cell viability was measured by MTT assay, and morphological observation was also performed. Gene expression of cytokines in macrophages was determined by real-time polymerase chain reaction. Phagocytic function assay was also performed in macrophage cells. Results : Kangai Fuzheng Powder had no direct detrimental effect on cancer cells. When macrophages were co-cultured with cancer cells, Kangai Fuzheng Powder had toxic effect on cancer cells. After exposing macrophages to Kangai Fuzheng Powder, macrophages transformed into activated form and the mRNA level of tumor necrosis factor-alpha, interleukin-1beta, interleukin-6, interleukin-10 and monocyte chemotactic protein-1 was significantly enhanced. Phagocytic activity of macrophages was dramatically potentiated. Conclusions : We demonstrated that anti-cancer effect of Kangai Fuzheng Powder was related to activation of macrophages including enhanced cytokine production and phagocytic function.

• Molecules and Cells
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• v.46 no.3
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• pp.165-175
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• 2023

The transcription factor Nrf2 was originally identified as a master regulator of redox homeostasis, as it governs the expression of a battery of genes involved in mitigating oxidative and electrophilic stress. However, the central role of Nrf2 in dictating multiple facets of the cellular stress response has defined the Nrf2 pathway as a general mediator of cell survival. Recent studies have indicated that Nrf2 regulates the expression of genes controlling ferroptosis, an iron-and lipid peroxidation-dependent form of cell death. While Nrf2 was initially thought to have anti-ferroptotic function primarily through regulation of the antioxidant response, accumulating evidence has indicated that Nrf2 also exerts anti-ferroptotic effects via regulation of key aspects of iron and lipid metabolism. In this review, we will explore the emerging role of Nrf2 in mediating iron homeostasis and lipid peroxidation, where several Nrf2 target genes have been identified that encode critical proteins involved in these pathways. A better understanding of the mechanistic relationship between Nrf2 and ferroptosis, including how genetic and/or pharmacological manipulation of Nrf2 affect the ferroptotic response, should facilitate the development of new therapies that can be used to treat ferroptosis-associated diseases.

• Biomolecules & Therapeutics
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• v.31 no.4
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• pp.456-465
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• 2023

Cervical tumors represent a prevalent form of cancer affecting women worldwide; current treatment options involve surgery, radiotherapy, and chemotherapy. Angiogenesis, the process of new blood vessel formation, is a crucial factor in cervical tumor growth. The molecular mechanisms underlying the effects of the liver kinase B1 (LKB1/STK11) tumor suppressor protein on tumor angiogenesis have not been elucidated. Therefore, we investigated the role of LKB1 in cervical tumor angiogenesis both in vitro and in vivo in this study. Our results demonstrated that LKB1 inhibited cervical tumor angiogenesis by suppressing the expression of angiogenesis-related factors such as vascular endothelial growth factor (VEGF) and hypoxia inducible factor-1α. LKB1 directly affected both carcinoma and vascular endothelial cells, resulting in a significant reduction in tumor growth and angiogenesis. Furthermore, LKB1 was found to bind to VEGF receptor 2 (VEGFR-2) and target the VEGFR-2-mediated protein kinase B/mechanistic target of rapamycin signaling pathway in endothelial cells, thereby reducing cervical tumor growth and angiogenesis. Our study provides new insights into the molecular mechanisms underlying the anti-tumor and anti-angiogenic effects of LKB1 in cervical cancer. These findings will help develop new therapeutic strategies for cervical cancer.

• Journal of Mechanical Science and Technology
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• v.14 no.1
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• pp.1-10
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• 2000

This work shows that it is possible to obtain information about more than one parameter from acoustic field information. A variety of ultrasonic Lamb wave modes were utilized to reconstruct thickness and density of an isotropic plate. An image reconstruction of one parameter (thickness of a plate) was carried out for four cases, i.e., the lowest symmetrical and anti symmetrical modes, and the fastest symmetrical and anti symmetrical Lamb waves among multiple modes. For two parameter reconstructions (thickness and density), the image processing was performed using the lowest symmetrical and antisymmetrical modes simultaneously. In this work, a modified version of algebraic reconstruction technique (ART), which is a form of finite-series expansion method, was employed to reconstruct the ultrasonically computed tomographic images. Results from several sample geometries are presented.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1746-1749
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• 1997

A distributed optical fiber temperature sensor can continually monitor the measurand at every point along of its fiber length. It is based on OTDR technics which used extreamlly weak backward scattered light called Raman scattering. When the Pulsed high intensity laser light injected into the optical fiber there are several kind of backscattered light such as Rayleigh, Stokes, and anti-Stokes, etc. caused by impurities molecular vibrations. The temperature distribution is derived form the intensity ratio Raman scatted light-Stokes versus anti-Stokes-and the time function between light injection and signal detection. It is shown that the priniciple of distributed sensing, the system desing, and the result of experiments.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.7
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• pp.325-331
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• 2001

A dynamic anti-windup method for state delayed control systems with input saturation is considered. Under the assumption that a linear controller has been designed for a state delayed control system based on the existing design technique which shows desirable nominal performance, an additional compensator is incorporated to provide a graceful performance degradation despite of input saturation. By regarding the difference of the controller states in the absence and presence of input saturation as an objective function, the dynamic compensator which minimizes it is determined explicitly. The proposed dynamic compensator is the closed form of plant and controller parameters. The proposed method not only provides graceful performance degradation, but it also guarantees the total stability of resulting systems. An illustrative example is provided to show the effectiveness of the proposed method.

• Journal of Power System Engineering
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• v.7 no.1
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• pp.51-59
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• 2003

The recent amount of container freight continuously has been increased, but the low efficiency of container crane causes jamming frequently in transportation and cargo handling at port. It is required that the working velocity and safety are improved by control of moving the trolley as quick as possible without large overshoot and any residual swing motion of container at the destination. In this paper, a LQ Fuzzy controller for a container crane is proposed to accomplish an optimal design of improved control system for minimizing the swing motion at destination. In this scheme a mathematical model for the system is obtained in state space form. Finally, the effectiveness of the proposed controller is verified through computer simulation.