• Korean Journal of Clinical Laboratory Science
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• v.52 no.2
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• pp.112-118
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• 2020

This study was undertaken to examine the effects and to investigate the relevant mechanisms of overexpressing stromal cell-derived factor-1 (SDF-1) produced by engineered mesenchymal stem cells, in a neurogenic bladder (NB) rat model. Sprague-Dawley (SD) rats (N=48) were randomly divided into 4 groups comprising 12 rats each: control group, Injury group, Injury+imMSC group, and Injury+SDF-1 eMSC group. Rats in the Injury+imMSC group were treated with imMSCs, whereas the Injury+SDF-1 eMSC group were administered SDF-1 eMSCs. After 4-weeks therapy, the bladder and pelvic nerve (PN) tissues were examined by subjecting to Masson's trichrome staining and immunofluorescence. Administration of SDF-1 eMSC resulted in improved smooth muscle content in the bladder tissue, significantly increased β-III tubulin expression of the PN, and enhanced SDF-1 expression (P<0.05). The bladder wall repair can be attributed to the overexpression of SDF-1 by SDF-1 eMSCs. Significantly increased SDF-1 expression was obtained in the Injury+SDF-1 eMSC group (P<0.05). The crushed PN also showed significant recovery in the Injury+SDF-1 eMSC group (P<0.05). In conclusion, our results indicate that SDF-1 eMSCs express more SDF-1 in vivo, thereby facilitating the repair of injured nerve and recovery of NB in rats.

• The Journal of the Acoustical Society of Korea
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• v.36 no.5
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• pp.361-369
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• 2017

Hemodynamic information in the carotid artery bifurcation is very important for understanding the development and progression mechanisms of cerebrovascular disease and for its early diagnosis and prediction of the progress. In this paper, we constructed a mock pulsatile blood circulation system using an anthropomorphic elastic vessel of the carotid artery bifurcation and ex vivo pig blood to acquire ultrasound images from blood and vessels synchronized with internal pressure while controlling the blood flow. Echogenicity, blood flow velocity, and blood vessel wall motion from the ultrasound images, and internal blood pressure were extracted over a cycle averaged from five cycles when the pulsatile pump rates are 20 r/min, 40 r/min, and 60 r/min. As a result, respectively, the peak systolic blood flow velocities were 20 cm/s, 25 cm/s, and 40 cm/s, the blood pressure differences were 30 mmHg, 70 mmHg, and 85 mmHg, the arterial walls were expanded to 0.05 mm, 0.15 mm, and 0.25 mm. Time-delayed cyclic variation of echogenicity compared to blood flow and pressure was observed, but the variation was minimal at 20 r/min. Time-synchronized cyclic variations of these parameters are important information for accurate input parameters and validation of the computational hemodynamic experiments which will provide useful information for the development and progress mechanisms of carotid artery stenosis.

• Journal of Microbiology and Biotechnology
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• v.27 no.12
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• pp.2119-2128
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• 2017

Citrinin (CIT) is a toxic secondary metabolite produced by fungi belonging to the Penicillium, Aspergillus, and Monascus spp. This toxin has been detected in many agricultural products. In this study, a strain Y3 with the ability to eliminate CIT was screened and identified as Cryptococcus podzolicus, based on the sequence analysis of the internal transcribed spacer region. Neither uptake of CIT by cells nor adsorption by cell wall was involved in CIT elimination by Cryptococcus podzolicus Y3. The extracellular metabolites of Cryptococcus podzolicus Y3 stimulated by CIT or not showed no degradation for CIT. It indicated that CIT elimination was attributed to the degradation of intracellular enzyme(s). The degradation of CIT by C. podzolicus Y3 was dependent on the type of media, yeast concentration, temperature, pH, and initial concentration of CIT. Most of the CIT was degraded by C. podzolicus Y3 in NYDB medium at 42 h but not in PDB medium. The degradation rate of CIT was the highest (94%) when the concentration of C. podzolicus Y3 was $1{\times}10^8cells/ml$. The quantity of CIT degradation was highest at $28^{\circ}C$, and there was no degradation observed at 3$5^{\circ}C$. The study also showed that acidic condition (pH 4.0) was the most favorable for CIT degradation by C. podzolicus Y3. The degradation rate of CIT increased to 98% as the concentration of CIT was increased to $20{\mu}g/ml$. The toxicity of CIT degradation product(s) toward HEK293 was much lower than that of CIT.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.11
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• pp.745-753
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• 2016

Micro methanol-steam reformer for fuel cell can effectively produce hydrogen as reforming response to steam takes place in low temperature (less than $250^{\circ}C$). This study conducted numerical research on this reformer. First, study set wall temperature of the reformer at 100, 140, 180 and $220^{\circ}C$ while methanol conversion efficiency was set in 0, 0.072, 3.83 and 46.51% respectively. Then, porosity of catalyst was set in 0.1, 0.35, 0.6 and 0.85 and although there was no significant difference in methanol conversion efficiency, values of pressure drop were 4645.97, 59.50, 5.12 and 0.45 kPa respectively. This study verified that methanol-steam reformer rarely responds under the temperature of $180^{\circ}C$ and porosity does not have much effect on methanol conversion efficiency if the fluid flowing through reformer lowers activation energy by sufficiently contacting reformer.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.6
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• pp.812-818
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• 2009

This study evaluated the effects of live yeast and yeast cell-wall mannan-oligosaccharide supplementation onperformance and nutrient digestibility during early lactation in cows fed a diet based on a mixture of corn silage and alfalfa hay as forage sources. Eight multiparous Holstein dairy cows (average days in milk, 27${\pm}$6) were used in a replicated 4${\times}$4 Latin square design. Diets contained 45% forage and 55% concentrate on a dry matter (DM) basis and treatments were: i) basal diet without additive (Control), ii) basal diet with 32 g/d of mannan-oligosaccharides (MOS), iii) basal diet with $1.2{\times}10^{10}$ colony forming units per day (cfu/d) of live yeast (Saccharomyces cerevisiae CNCM 1-1077; SC), and iv) basal diet with a mixture of MOS (32 g/d) and SC ($1.2{\times}10^{10}$ cfu/d; MOS+SC). Treatments had no effect (p>0.05) on DM intake and yields of milk, 3.5% fat-(FCM) and energy-corrected milk (ECM), and on milk fat percentage, body condition score and blood metabolites. Compared with the Control, only supplementation of SC resulted in numerically higher yields of FCM (41.9 vs. 40.1 kg/d) and ECM (41.8 vs. 40.3 kg/d), and milk fat percentage (3.64 vs. 3.43%). While the MOS diet had no effects on performance compared to the Control, the combination treatment MOS+SC increased milk protein percentage (p<0.05). Also, the MOS supplementation, both alone or in combination with SC, numerically increased milk fat percentage. The SC supplementation increased apparent digestibility of DM and crude protein while the MOS supplementation did not affect digestibility. Concentrations of total volatile fatty acids (VFA) and ruminal pH were similar across treatments. Overall results indicated that supplementation of MOS produced variable and inconsistent effects on rumen metabolism and performance, whereas SC supplementation improved nutrient digestibility and numerically increased FCM and ECM yields, which could not be enhanced by the combined supplementation of MOS+SC. According to our experimental condition, there was no effect of MOS alone or in combination with SC on dairy cow performance.

• Journal of the Korea Institute of Building Construction
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• v.11 no.3
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• pp.229-237
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• 2011

The pullout test is a nondestructive testing method certified by the American Society for Testing and Materials (ASTM) and British Standards (BS). Research has shown that it is very reliable in terms of evaluating the concrete strength of reinforced concrete members. However, the pullout test is rarely performed on domestic construction sites due to the complex procedures and high costs involved. This study proposes a new pullout test composed of a post installable break-off bolt, an insert nut, and a pullout tester, which satisfy both economical and practical purposes on a construction site. Three different types of special fastening methods, a temporary fixed bolt, a plastic fixed panel, and a fixed bar, have been developed. A pullout tester is proposed that is driven by the circle force introduced into a handle composed of eight gears without a load cell and a hydraulic cylinder. The serviceability and reliability of these instruments were investigated through experiments at construction sites. Furthermore, the sample pullout test with a wall specimen was conducted to estimate the usefulness of the temporary fixed bolt type of fastening methods and pullout devices. Eventually, the developed instruments will be useful on construction sites if minor requirements are met.

• Journal of Mushroom
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• v.2 no.4
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• pp.200-206
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• 2004

The optimal temperature for mycelial growth the F. fomentarius was $30^{\circ}C$ and the range of the temperature for mycelial growth wsa about 10~30. The optimal pH for the growth was 4.0. The percentage of weight loss percentage wsa 17.4%. The percentage of WEC extractives wsa increased to 2.24%. The observation of micromorphological showed that the detected cell wall were erosive and thinning as typical degradation pattern of white-rot fungi.

• Journal of Life Science
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• v.25 no.9
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• pp.1021-1026
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• 2015

Invertase (β-D-fructosfuranosidase, EC 3.2.1.26) catalyzes the hydrolysis of sucrose into D-glucose and D-fructose. Three biochemical subgroups of invertases have been investigated in plants: vacuolar (soluble acid), cytoplasmic (soluble alkaline), and cell wall-bound (insoluble acid) invertases. An isoform of neutral invertase was purified from pea seedlings (Pisum sativum L.) and treated with gibberellic acid (GA) by sequential procedures consisting of ammonium sulfate precipitation, ion-exchange chromatography, absorption chromatography, and reactive green-19 affinity chromatography. The results of the overall insoluble invertase purification were a 430-fold increase. The purified neutral invertase was not glycosylated and had an optimum pH between neutral and alkaline (pH 6.8-7.5). It was inhibited by Tris, as well as by heavy metals, such as Hg²⁺ and Cu²⁺. Typical Michaelis–Menten kinetics were observed when the activity of the purified invertase was measured, with sucrose concentrations up to 100 mM. The K_m and V_max values were 12.95 mM and 2.98 U/min, respectively. The molecular mass was around 20 kDa. The sucrose-cleaving enzyme activity of this enzyme is similar to that of sucrose synthase and fructosyltransferase, but its biochemical characteristics are different from those of sucrose synthase and fructosyltransferase. Based on this biochemical characterization and existing knowledge, neutral INV is an invertase isoform in plants.

• Food Science of Animal Resources
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• v.29 no.5
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• pp.619-626
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• 2009

As a trial for the development of a new starter culture for yogurt products, more than two hundred lactic acid bacteria strains were isolated from raw milk and healthy human feces. The strains that showed excellent growth and acid production ability in the 10% skim milk media were selected and identified as Lactobacillus casei through the API carbohydrate fermentation pattern and 16S rDNA sequence analysis. L. casei CU2604 was further investigated for its physiological characteristics as a starter culture compared with a commercial strain. The CU2604 strain showed good acid production and growth characteristics in milk, which were comparable to those of the L. casei Shirota strain. Despite the fact that both these strains displayed the same sugar fermenting pattern and PFGE band pattern, and had similar growth characteristic in milk, L. casei CU2604 exhibited different fatty acid composition in the cell wall, showed more tolerance to bile and to pH, and presented better growth inhibition activity against pathogenic bacteria. Based on these results, the L. casei CU2604 strain holds great promise for use as a novel and efficient starter culture in the production of yogurt. Additional studies on the probiotic characteristics of this strain are currently being conducted.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.4
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• pp.247-255
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• 2003

A bacterium, KJA-118 showing a strong chitinase activity, was isolated and identified as Bacillus cereus. The strain produced maximum level of chitinase, when grown aerobically at $30^{\circ}C$ for 4 days in basal broth containing 1% colloidal chitin in the initial pH adjusted to 6.0. Among various carbon sources such as crab shell powder, chitin powder, colloidal chitin, and R. solani mycelium, maximum chitinase activity was found in culture broth supplemented with R. solani mycelium. When KJA-118 was incubated with R. solani, the cell wall of the fungus was found to be completely destroyed. SDS-PAGE and active staining results revealed that KJA-118 produced three isoforms of chitinase with molecular weights of 68 kDa, 47 kDa, and 37 kDa. When the suspension of KJA-118 was treated to cucumber seedlings, reducing rate of damping-off caused by R. solani was about 28.1%.