• The Plant Pathology Journal
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• v.26 no.1
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• pp.57-62
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• 2010

Low-molecular-weight secondary metabolites from plants play an important role in reproductive processes and in the defense against environmental stresses or pathogens. In the present study, we isolated various volatiles and phenolic compounds from white Rosa rugosa flowers, and evaluated the pharmaceutical activities of these natural products in addition to their ability to increase survival in response to environmental stress and pathogen invasion. The DPPH and hydroxyl radical-mediated oxidation assay revealed that the white rose flower extract (WRFE) strongly scavenged free radicals in a dose dependent manner. Moreover, WRFE inhibited the growth of E. coli and fatally attacked those cells at higher concentration (>0.5 mg/mL). FITC-conjugated Annexin V stain provided further evidence that WRFE had strong antimicrobial activity, which may have resulted from a cooperative synergism between volatiles (e.g. 1-butanol, dodecyl acrylate and cyclododecane) and phenolic compounds (e.g. gallic acid) retained in WRFE. In conclusion, secondary metabolites from white rose flower hold promise as a potential natural source for antimicrobial and non-chemical based antioxidant agents.

• Korean Journal of Medicinal Crop Science
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• v.8 no.1
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• pp.9-13
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• 2000

To determine the proper carbon and nitrogen sources and their proper levels for mass micro propagation of Scrophularia buergeriana Miquel, tonic and curing cough experiment were applied and a method for mass cultivation by using bioreactors (2.5 L) was expinined. Proper ratio of $NH_4NO_3\;:\;$KNO_3$ was 413 mg/L : 1900 mg/L for multiple shoot production. Sucrose was more effective than glucose or fractose as carbon source and 3% concentration was good for shoot formation. Total nitrogen was not detected after six weeks both in 500 ml flask and bioreactor culture. Sucrose was decreased sharply after two weeks and there was no sucrose left after three weeks both in 500 ml flask and bioreactor culture. The stirrer in bioreactor caused shear stress to shoots severely. The sphere type bioreactor was better than the cylinder type and removal of inner loop in sphere type was more effective to avoid shear stress.

• Journal of Microbiology
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• v.41 no.1
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• pp.34-40
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• 2003

Aspergillus nidulans, a homothalic ascomycete, has a complete sexual reproductive cycle as well as an asexual one. Both sexual and asexual development are known to be genetically programmed, but are also strongly affected by environmental factors including nutrients, light, temperature and osmolarity. We have examined these factors to define favored conditions for fruiting body (cleistothecium) formation. In general, fruiting body formation was enhanced where carbon and nitrogen sources were sufficient. Limitation of C-source caused predominant asexual development while inhibiting sexual development. When higher concentrations of glucose were supplied, more cleistothecia were formed. Other carbon sources including lactose, galactose and glycerol made the fungus develop cleistothecia very well, whereas acetate caused asexual sporulation only. Organic nitrogen sources like casein hydrolysate and glycine, and an increase in nitrate or ammonium concentration also enhanced sexual development. In addition to nutrient effects, low levels of aerobic respiration, caused either by platesealing or treatment with various chemicals, favored sexual development. Carbon limitation, light exposure and a high concentration of salts promoted asexual development preferentially, suggesting that stress conditions may drive the cell to develop asexual sporulation while comfortable and wellnourished growth conditions favored sexual development.

• Proceedings of the Korean Fiber Society Conference
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• 1990.06b
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• pp.36-37
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• 1990

In the past, facile dissolution of cellulose has been hampered by the lack of suitable nondegrading solvents. Recently, this problem has been solved in our laboratory by the discovery of an inexpensive, convenient solvent system, that is the mixture of $NH_3\;and\;NH_4SCN$, for cellulose. Also, the $cellulose/NH_3/NH_4SCN$ solution system has been found to form the anisotropic, i.e., liquid crystalline phase. It is believed that both the cholesterio and the nematic phase occur. This finding has prompted extensive on-going researoh on the formation of the liquid crystalline phase from an inexpensive natural source such as cellulose since the nematic phase is envisioned as an excellent precursor sources for products with desirable properties, for example, high modulus and high strength. This interest naturally leads to a desire to understand the theological properties of the nematic phase so that the transformation of the nematic phase to the solid state with desirable properties can be efficiently accomplished, ;From this point of view, the theological behavior of the $cellulose/NH3_/NH_4SCN$ system has been studied as a function of shear rate and shear stress over a wide range of solvent compositions, cellulose concentration, centrifugation and urea contents, Results indicate that the viscosity decreases with increasing shear rate. A marked shear thinning behavior and a quasi-Newtonian behavior were observed in the low shear rate region and in the high shear rate region, respectively for all solvent compositions. The $cellulose/NH_3/NH_4SCN$ solution system only exhibited the viscosity increase with increasing cellulose concentration and failed to show the viscosity drop generally observed at the point of incipience of liquid crystal formation, This may be due to the gel-like nature of the solution by the association of the rodlike molecules into bundles which may serve as crosslinking points giving the cellulose solution a network structure. Also, simply hydrogen bonding may be so restrictive of molecular mobility that a viscosity drop is blocked. In addition to the above results, yield stress and thixotropy were also observed in the $cellulose/NH_3/NB_4SCN$ solution system which are characteristics of liquid crystal and gel, The results of the effect of centrifugation on viscosity show that viscosity decreases by the application of centrifugation. This may be explained by the change of the piled polydomain structure to the dispersed polydomain structure due to the pressure gradient generated during centrifugation.ation.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.7
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• pp.957-964
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• 2011

The present study was conducted to evaluate the effects of fermented soybean meal (FSBM) on the level of cortisol hormone and immune-related serum proteins in weaned calves after experimentally induced lipopolysaccharide (LPS) challenge. Holstein neonatal calves (n = 21; 8 males and 13 females, BW = $42.2{\pm}6.15$ kg) were randomly allocated to one of two dietary treatments: SBM (control calf starter having soybean meal (SBM) as a main protein source) and FSBM (substitute SBM in control diet with FSBM) groups. All calves were fed milk replacer using an automatic milk-feeder according to step-down milking method and weaned at 7 weeks old. Experimental diets were given to calves ad libitum throughout the experimental period. For LPS challenge, all calves except negative control animals given phosphate buffered saline (PBS), were injected subcutaneously with Salmonella typhimurium LPS on day 7 (D7) after weaning (D0). No significant difference in growth performance and milk intake was observed between SBM and FSBM calves. Feeding FSBM diet resulted in significantly (p<0.05) higher LPS-specific IgG at D12 and D19 and LPS-specific IgA at D19 in peripheral blood. Calves fed with FSBM diet also had significantly (p<0.05) higher concentration of serum haptoglobin (Hp) at D8. Overall concentration of cortisol in FSBM group was considerably lower than that of SBM group. Results from current study indicate that FSBM may provide beneficial effects in alleviating weaning stress and enhance immune status of weaned calves.

• Advances in Traditional Medicine
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• v.8 no.3
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• pp.266-278
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• 2008

Erythrina stricta, a deciduous tree widely used traditionally in indigenous system of medicine for various ailments such as rheumatism, fever, leprosy, epilepsy etc. The leaves of Erythrina stricta was extracted with ethanol (70%) and used for the evaluation of various in vitro antioxidant assays which includes H - donor activity, nitric oxide scavenging, superoxide anion scavenging, reducing ability, hydroxyl radical, hydrogen peroxide scavenging, total phenolic content, total flavonoid content, total antioxidant activity by thiocyanate and phosphomolybdenum method, metal chelating, $\beta$-carotene bleaching, total peroxy radical assays. The pro-oxidant activity was measured using bleomycin-dependent DNA damage. Ex vivo models like lipid peroxidation and erythrocyte haemolysis were also used to study the antioxidant property of the extract. The various antioxidant activities were compared with suitable standard antioxidants such as ascorbic acid, butylated hydroxyl toluene, $\alpha$-tocopherol, curcumin, quercetin and Trolox. The generation of free radicals viz. $O_2^{{\cdot}-}$, $OH^{\cdot}$, $H_2O_2$, $NO^{\cdot}$ and peroxyl radicals were effectively scavenged by the ethanolic extract of Erythrina stricta. In all the methods, the extract offered strong antioxidant activity in a concentration dependent manner. The total phenolic content, flavonoid content and total antioxidant activity in Erythrina stricta were determined as microgram (g) pyrocatechol, quercetin and $\alpha$-tocopherol equivalent/mg respectively. The extract did not exhibit any prooxidant activity when compared with ascorbic acid. The results obtained in the present study clearly indicates that Erythrina stricta scavenges free radicals and reduces lipid peroxidation, ameliorating the damage imposed by oxidative stress in different disease conditions and serve as a potential source of natural antioxidant.

• Journal of Environmental Science International
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• v.31 no.2
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• pp.141-148
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• 2022

In this study, the inhibition of ammonia on anaerobic digestion of butyric acid was evaluated and the potential alleviating effects of such ammonia inhibition by the addition of magnetite particles were investigated. Independent anaerobic batch tests fed with butyric acid as a sole organic source were conducted in twenty 60-mL glass bottles with 10 different treatment conditions, comprising ammonia: 0.5, 2.0, 4.0, 6.0, and 7.0 g total ammonia nitrogen (TAN)/L and magnetite particles: 0 mM and 20 mM. The increase in ammonia concentration did not cause significant inhibition on methane yield; however, a significant inhibition on lag time and specific methane production rate was observed. The IC₅₀ in the control treatments (without magnetite addition) was estimated as 6.2654 g TAN/L. A similar inhibition trend was observed in magnetite-added treatments; however, the inhibition effect by ammonia was significantly alleviated in lag time and specific methane production rate when compared to those in the control treatments. The lag time was shortened by 1.6-46.3%, specific methane production rate was improved by 6.0-69.0%. In the magnetite-added treatments, IC₅₀ was estimated as 8.5361 g TAN/L. This study successfully demonstrated the potential of magnetite particles as an enhancer in anaerobic digestion of butyric acid under conditions of ammonia stress.

• Korean Journal of Optics and Photonics
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• v.9 no.3
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• pp.162-167
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• 1998

$SiO_xF_y$ optical thin films of lower refractive indices than glass substrates were fabricated by the CF$_4$ ion beam assisted deposition method and the optical, structural and chemical properties of them were investigated. Refractive index of $SiO_xF_y$ films was varied from 1.455 to 1.394 by decreasing the anode voltage or from 1.462 to 1.430 by increasing the current density of end-Hall ion source. FT-IR and XPS analyses show that as the F concentration increases, the Si-O bond at $1080m^{-1}$ shifts to higher wavenumber, the OH bonds are reduced drastically, and the fluorine atoms at the air-film interface are desorbed out by reacting with $H_2O$ in the atmosphere. $SiO_xF_y$ thin films are amorphous by the XRD analysis and have the compressive stress below 0.3 GPa. As an application of $SiO_xF_y$ thin films a two-layer antireflection coating was fabricated using a $SiO_xF_y$ film as a low refractive index layer and a Si film as an absorbing one.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.4
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• pp.299-304
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• 2007

There are to be some cracks on the material degradation part or the stress concentration parts of the main members, which carry on over-loads, of structures. Because these cracks can be used to evaluate the structural health status, it is important to monitor the crack growth for maintaining the structural safety. In this study, the fiber Bragg grating sensor with a drop ball was developed as a sensor for crack growth detection of an existing crack. The crack growth detection sensor was constructed with three parts: a probe part, a wavelength controling light source and receiver part, and an impact part. The probe part was just formed with a fiber Bragg grating optical fiber The wavelength controling light source part was composed of a current supplying circuit, a DFB laser diode, and a TEC controling circuit for wavelength control. Also, the impact part was just implemented by dropping a steel ball. The performance of this sensor was confirmed by the experiments of the crack detection with an aluminum plate having one existing crack. According to these experiments, the difference of the sensor signal outputs was correlated with the crack length. So, it was confirmed that this sensor could be applied to monitor the crack growth.

• Korean Journal of Organic Agriculture
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• v.28 no.4
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• pp.659-677
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• 2020

Leonurus japonicus (L. japonicus) Houtt., a biennial plant in the Lamiaceae family is broadly distributed in Asia such as Korea, China, Japan. The aerial part of L. japonicus is used as a traditional medicine to treat uterine disease including dysmenorrhea, amenorrhea, sterility. In this study, we examined the antioxidant and anti-inflammatory effects of L. japonicus ethanol extracts. The antioxidant activity of L. japonicus was measured by total polyphenol and flavonoid content, and DPPH, ABTS scavenging, reducing power activity, and intracellular ROS expression assay. The anti-inflammatory effects were measured by nitric oxide (NO), cytokines (TNF-α and IL-1β) production and inflammatory protein expression in LPS-induced RAW 264.7 cells. Total polyphenol and flavonoid content of L. japonicus were 51.40 ± 0.47 mg of gallic acid equivalents/g and 73.28 ± 0.10 mg of rutin equivalents/g respectively. DPPH, ABTS radical scavenging activity and reducing power activity tended to increase concentration-dependent and treatment L. japonicus with 400 ㎍/mL reduced ROS production by 69.5%. Furthermore, L. japonicus inhibited NO, TNF-α and IL-1β production in a concentration-dependant manner and reduced the expression levels of inflammatory proteins via regulating NF-κB, MAPK pathway. Therefore, we suggest that L. japonicus could be a natural antioxidants and medicinal source to treat oxidative stress and inflammation-related disease.