• Mycobiology
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• v.39 no.3
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• pp.174-181
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• 2011

The purpose of the present study was to investigate the influence of cultural and environmental parameters affecting the growth and bioactive metabolite production of the rare strain VUK-10 of actinomycete Pseudonocardia, which exhibits a broad spectrum of in vitro antimicrobial activity against bacteria and fungi. Production of bioactive metabolites by the strain was high the in modified yeast extract-malt extract-dextrose (ISP-2) broth, as compared to other tested media. Glucose (1%) and tryptone (0.25%) were found to be the most suitable carbon and nitrogen sources, respectively, for optimum production of growth and bioactive metabolites. Maximum production of bioactive metabolites was found in the culture medium with initial pH 7 incubated with the strain for four days at $30^{\circ}C$, under shaking conditions. This is the first report on the optimization of bioactive metabolites by Pseudonocardia sp. VUK-10.

• Korean Journal of Agricultural Science
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• v.36 no.1
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• pp.51-56
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• 2009

When the parasitic wasp Microplitis croceipes experiences odors while feeding on sugar water, it learns to associate the odors with sugar and thereafter exhibits typical food searching behavior in response to the odors. Previous studies have shown that this wasp can be used for detection of the small amount of explosives or other volatile chemicals. In the present study, we examined if this wasp can learn and report narcotic odors. Males of M. croceipes were trained to link sugar water with pseudo-narcotic scents that have been used for training narcotic detection dogs, and their behavioral response to the trained odors was observed. The males that had been given either an odor or sugar water did not show any positive response to the odors. However, when the wasps were given a combination of sugar water and either the pseudo-Cocaine, Heroin, LSD or Marihuana, they quickly learned to associate the odors with sugar, and thereafter positively responded to those odors. Our results suggest that this wasp can be used for detection of these narcotics.

• Smart Structures and Systems
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• v.7 no.1
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• pp.27-40
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• 2011

Geopolymer concrete is finding a growing number of niche applications in the field of civil engineering due to its high compressive strength and strength gain rate, retainage of structural properties in elevated temperature environments, chemical stability in highly acidic conditions and environmental benefits. Combining the above mentioned characteristics with induced electrical conductivity, could enable geopolymer cement to serve as a smart and sustainable cementitious material suitable for health monitoring of civil structures. Carbon fibers were added to fresh geopolymer and OPC (ordinary Portland cement) mixes to enhance their electrical conductivities. AC-impedance spectroscopy analysis was performed on the specimens with fiber fraction ranging from 0.008 to 0.8 with respect to the weight of cementitious binder, to measure their electrical resistivity values and to determine the maximum beneficial fiber content required to attain electrical percolation. Experimental observations suggest that CFR-geopolymer cement exhibits superior performance to CFR-OPC in terms of conducting electrical current.

• Journal of Sensor Science and Technology
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• v.19 no.5
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• pp.337-341
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• 2010

In this work, the nanocrystalline ZnO/polycrystalline(poly) aluminum nitride(AlN)/ Si-layered structure was fabricated for humidity sensor applications based on surface acoustic wave(SAW). The ZnO film was used as a sensitive material layer. The ZnO and AlN(0002) were deposited by a sol-gel process and a pulse reactive magnetron sputtering, respectively. The ZnO sensitive films coated on AlN have a hexagonal wurtzite structure after the thin films annealed at $400^{\circ}C$, $500^{\circ}C$ and $600^{\circ}C$. The surface of the film exhibits sponginess and a nanometer particle size(below 50 nm). The largest shift in the frequency response was at approximately 200 kHz(the relative humidity: 10 %~90 %) for the structure annealed at $400^{\circ}C$. The effect of the change in the environmental temperature on the frequency response of the SAW humidity sensor was also investigated.

• Toxicological Research
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• v.33 no.4
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• pp.273-282
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• 2017

Chemoprevention entails the use of synthetic agents or naturally occurring dietary phytochemicals to prevent cancer development and progression. One promising chemopreventive agent, procyanidin, is a naturally occurring polyphenol that exhibits beneficial health effects including anti-inflammatory, antiproliferative, and antitumor activities. Currently, many preclinical reports suggest procyanidin as a promising lead compound for cancer prevention and treatment. As a potential anticancer agent, procyanidin has been shown to inhibit the proliferation of various cancer cells in "in vitro and in vivo". Procyanidin has numerous targets, many of which are components of intracellular signaling pathways, including proinflammatory mediators, regulators of cell survival and apoptosis, and angiogenic and metastatic mediators, and modulates a set of upstream kinases, transcription factors, and their regulators. Although remarkable progress characterizing the molecular mechanisms and targets underlying the anticancer properties of procyanidin has been made in the past decade, the chemopreventive targets or biomarkers of procyanidin action have not been completely elucidated. This review focuses on the apoptosis and tumor inhibitory effects of procyanidin with respect to its bioavailability.

• Bulletin of the Korean Chemical Society
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• v.20 no.5
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• pp.556-558
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• 1999

Lead-selective PVC membrane electrodes based on newly synthesized bis(crown ether)s containing 18-crown-6 moiety was prepared using standard PVC membrane composition. In order to monitor lead in environmental samples by lead sensor, especially good selectivity over alkali and alkaline earth metals has to be obtained. Thus, responses of the PVC membrane prepared with new bis(crown ether)s and Fluka ionophore V (crown ether) base to various cations include lead, alkali and alkaline earth metal ions were investigated for their use as a lead sensor. The polymeric liquid membrane based on trans-1 8-crown-6 ether exhibits the best overall potentiometric performances as a lead-selective electrode in terms of a wide linear dynamic range (between 10-6 and 10-2 M, Pb2+), excellent detection limit (less than 10-6 M) and good durability within limited error. The preferences of lead over other cations, such as Ag+, Hg2+, Na+, Ca2+ and even K+ in the aforementioned electrode are much better than the Fluka ionophore V system.

• Structural Engineering and Mechanics
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• v.72 no.1
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• pp.19-30
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• 2019

The mechanical behavior of Fiber Reinforced Cementitious Composites (FRCC) under direct shear is studied through experiment and analytical simulation. The cementitious composite considered contains 55% replacement of cement with fly ash and 2% (volume ratio) of short discontinuous synthetic fibers (in the form of mass reinforcement, comprising PVA - Polyvinyl Alcohol fibers). This class of cementitious materials exhibits ductility under tension with the formation of multiple fine cracks and significant delay of crack stabilization (i.e., localization of cracking at a single location). One of the behavioral parameters that concern structural design is the shear strength of this new type of fiber reinforced composites. This aspect was studied in the present work with the use of Push-off tests. The shear strength is then compared to the materials' tensile and splitting strength values.

• Journal of Electrochemical Science and Technology
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• v.14 no.3
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• pp.215-221
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• 2023

A rapid and environment-friendly electrochemical sensor to determine the chemical oxygen demand (COD) has been developed. The boron-doped diamond (BDD) thin-film electrode is employed as the anode, which fully oxidizes organic pollutants and provides a current response in proportion to the COD values of the sample solution. The BDD-based amperometric COD sensor is optimized in terms of the applied potential and the solution pH. At the optimized conditions, the COD sensor exhibits a linear range of 0 to 80 mg/L and the detection limit of 1.1 mg/L. Using a set of model organic compounds, the electrochemical COD sensor is compared with the conventional dichromate COD method. The result shows an excellent correlation between the two methods.

• Advances in nano research
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• v.16 no.2
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• pp.201-215
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• 2024

The present research study emphasizes the utilization of mathematical simulation on a nanoelectromechanical systems (NEMS) sensor to facilitate the detection of injuries in players and equipment. Specifically, an investigation is conducted on the thermal buckling behavior of a small-scale truncated conical, cylindrical beam, which is fabricated using porous functionally graded (FG) material. The beam exhibits non-uniform characteristics in terms of porosity, thickness, and material distribution along both radial and axial directions. To assess the thermal buckling performance under various environmental heat conditions, classical and first-order nonlocal beam theories are employed. The governing equations for thermal stability are derived through the application of the energy technique and subsequently numerically solved using the extended differential quadratic technique (GDQM). The obtained results are comprehensively analyzed, taking into account the diverse range of effective parameters employed in this meticulous study.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5455-5461
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• 2012

Luteolin is a plant flavonoid which exhibits anti-oxidative, anti-inflammatory and anti-tumor effects. However, the antiproliferative potential of luteolin is not fully understood. In this study, we investigated the effect of luteolin on cell cycling and apoptosis in human esophageal squamous carcinoma cell line Eca109 cells. MTT assays showed that luteolin had obvious cytotoxicity on Eca109 with an $IC_{50}$ of $70.7{\pm}1.72{\mu}M$ at 24h. Luteolin arrested cell cycle progression in the G0/G1 phase and prevented entry into S phase in a dose- and time-dependent manner. as assessed by FCM. Luteolin induced apoptosis of Eca109 cells was demonstrated by AO/EB staining assay and annexin V-FITC/PI staining. Moreover, luteolin downregulated the expression of cyclin D1, survivin and c-myc, and it also upregulated the expression of p53, in line with the fact that luteolin was able to inhibit Eca109 cell proliferation.