Publications by authors named "Joon-Ho Keum"

A shift from coal to liquefied natural gas for electricity generation can mitigate CO emissions and respond to the intermittent and variable characteristics of renewable energy. With this objective, numerical simulation was performed in this study to determine the optimal position of the methane injector and evaluate the achievable reduction in NO emissions before applying methane cofiring to an existing 550 MW tangentially fired pulverized-coal boiler (Boryeong Unit 3). The combustion and NO reduction in the furnace were intensively analyzed based on the methane cofiring rate (up to 40%).

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Objective: Cheongseoikki-tang (CIT, Korean), also called Qingshu Yiqi decoction () and Seisho-ekki-to (Japanese), is well known as an effective traditional combination of herbs for treating cardiovascular diseases. This study was to research its effects on bone marrow-derived mast cell (BMMC)-mediated allergy and inflammation mechanisms.

Methods: In this study, the biological effect of Cheongseoikki-tang ethanol extract (CITE) was evaluated, focusing on its effects on the production of allergic mediators by phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187 (A23187)-stimulated BMMCs.

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OBJECTIVE: To elucidate the molecular mechanisms underlying the anti-inflammatory effects of Danggui Liuhuang Decoction () or Dangkwiyughwang-tang (DGLHT) water extract. METHODS: Effect of DGLHT on the lipopolysaccharide (LPS)-induced production of several pro-inflammatory mediators, including nitric oxide (NO), prostaglandin E(2) (PGE(2)), and interleukin-6 (IL-6) were examined by using enzymelinked immunosorbent assay. To determine the underlying mechanism of the inhibitory effects of DGLHT, the expression levels of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) protein, as well as iNOS, COX-2, and IL-6 mRNA levels were examined by Western blot and reverse transcription polymerase chain reaction (RT-PCR).

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Tetrandrine (TET) is a bis-benzylisoquinoline alkaloid derived from the radix of Stephania tetrandra S. Moore. TET performs a wide spectrum of biological activities.

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Methicillin-resistant Staphylococcus aureus (MRSA) along with other resistant bacteria have become a significant social and clinical problem. Therefore, there is an urgent need to develop bioactive compounds from natural products as alternatives to the very few antibiotics that remain effective. Recently, the efflux mechanism has been identified as the main contributor to antibiotic resistance in bacteria.

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Sanguinarine is a benzophenanthridine alkaloid derived from the root of Sanguinaria canadensis. It is known to perform a wide spectrum of biological activities. The aim of this study is to examine the antimicrobial actions of sanguinarine against methicillin-resistant Staphylococcus aureus (MRSA).

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Few new drugs are available against methicillin-resistant Staphylococcus aureus (MRSA), because MRSA has the ability to acquire resistance to most antibiotics, which consequently increases the cost of medication. The objective of this study is to evaluate the potentiation of sanguinarine (SN) with selected antibiotics (ampicillin [AC], oxacillin [OX], norfloxacin [NR], ciprofloxacin [CP], and vancomycin [VC]) against MRSA. Minimum inhibitory concentration was determined by using the broth microdilution method and the synergistic effect of AC, OX, NR, CP, and VC in combination with SN was examined by the checkerboard dilution test.

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Gomisin N is a bioactive compound and a prominent anti-allergic agent found in the fruits of tree Schizandra chinensis. However, its effects on the bone marrow-derived mast cell (BMMC)-mediated allergy and inflammation mechanism remain unknown. In this study, the biological effects of gomisin were evaluated while focusing on its effects on the allergic mediator in PMA + A23187-stimulated BMMCs.

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Sinomenine is an alkaloid compound and a prominent anti-allergic agent found in the root of the climbing plant Sinomenium acutum. However, its effects on the bone marrow-derived mast cell (BMMC) mediated allergy and inflammation mechanism remain unknown. In this study, the biological effects of sinomenine were evaluated while focusing on its effects on the allergic mediator in PMA plus A23187-stimulated BMMCs.

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Methicillin-resistant Staphylococcus aureus (MRSA) is a substantial contributor to morbidity and mortality. In search of a natural products capable of inhibiting this multidrug resistant bacteria, we have investigated the antimicrobial activity of emodin (EM) isolated from Rheum palmatum L. (Polygonaceae) against 17 different strains of the bacterium.

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