• Analytical Science and Technology
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• v.19 no.1
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• pp.65-72
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• 2006

In this study, the filtering characteristics of sulfur gases were investigated from a number of respects. For the purpose of this study, a standard gas containing a single oxidized S ($SO_2$) and five reduced S compounds (RSCs) including $H_2S$, $CH_3SH$, DMS, $CS_2$, and DMDS was prepared. After flowing this standard gas through a glass fiber filter, its removal efficiencies were examined by comparing the concentrations between prior to and after its passage. The results indicated that almost complete removal of $SO_2$ was achieved by this filtering, while the patterns for RSCs were distinguished by such factors as molecular weight or reactivity. It was found that about 60% of the most reactive RSC, $H_2S$ was removed by filter, while the heavy RSC generally showed removal rate of about 5% or less.

• Journal of Korean Society of Disaster and Security
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• v.16 no.2
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• pp.65-73
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• 2023

Fishways are essential structures that must be installed in rivers to facilitate the movement of fish between upstream and downstream areas. However, the efficiency of fish passage varies depending on the flow conditions within the fishway. Therefore, this study examined the fish-friendly flow characteristics within a stepped fishway at different overflow depths using FLOW-3D, and conducted experiments for model validation. The key parameters affecting fish swimming ability include velocity, turbulent kinetic energy, and energy dissipation rate. These factors were assessed using a simulated fish species, the zacco platypus, to evaluate the suitability of fish-friendly flow condition. It was confirmed that overflow depth significantly influences fish behavior, and an appropriate overflow depth is required for stepped fishway design. The results of this study are expected to serve as fundamental data for the design of stepped fishways in the future.

• Journal of Veterinary Science
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• v.25 no.3
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• pp.36.1-36.15
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• 2024

Importance: The intravenous administration of adipose tissue-derived mesenchymal stem cells (AdMSCs) in veterinary medicine is an attractive treatment option. On the other hand, it can result in severe complications, including pulmonary thromboembolism (PTE). Objective: The present study assessed the occurrence of PTE after the intravenous infusion of canine AdMSCs (cAdMSCs) into experimental animals. Methods: Five-week-old male BALB/c hairless mice were categorized into groups labeled A to G. In the control group (A), fluorescently stained 2×10⁶ cAdMSCs were diluted in 200 µL of suspension and injected into the tail vein as a single bolus. The remaining groups included the following: group B with 5×10⁶ cells, group C with 3×10⁶ cells, group D with 1×10⁶ cells, group E with 1×10⁶ cells injected twice with a one-day interval, group F with 2×10⁶ cells in 100 µL of suspension, and group G with 2×10⁶ cells in 300 µL of suspension. Results: Group D achieved a 100% survival rate, while none of the subjects in groups B and C survived (p = 0.002). Blood tests revealed a tendency for the D-dimer levels to increase as the cell dose increased (p = 0.006). The platelet count was higher in the low cell concentration groups and lower in the high cell concentration groups (p = 0.028). A histological examination revealed PTE in most deceased subjects (96.30%). Conclusions and Relevance: PTE was verified, and various variables were identified as potential contributing factors, including the cell dose, injection frequency, and suspension volume.

• Journal of dental hygiene science
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• v.10 no.6
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• pp.465-472
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• 2010

This study surveyed salivary flow rate, salivary viscosity, and salivary buffering capacity in order to intensively analyze salivary factors among factors of occurrence in dental caries for finding mutually different factors that function in occurrence of dental caries depending on each individual. Even the acid body within dental plaque has great influence upon dental caries. Thus, the comparative analysis was carried out by surveying the hydrogen ion concentration in dental plaque. The following results were obtained in this study. 1. The average decayed teeth in the survey subjects stood at 1.67 piece. The extracted teeth caused by dental caries stood at 0.47 piece. The filled teeth were indicated to be 6.31 pieces. Accordingly, the average permanent dental caries experience teeth were surveyed to be 8.44 pieces. 2. The results according to dental caries activity test method were indicated to be $12.56{\pm}4.15ml$ for the average stimulated salivary flow rate, $3.89{\pm}1.83ml$ for non-stimulated salivary flow rate, $1.49{\pm}0.69$ for salivary viscosity, and $8.51{\pm}2.44$ for salivary buffering capacity. The hydrogen ion concentration test in dental plaque was indicated to be $5.62{\pm}0.50$ for before brushing teeth, $5.23{\pm}0.58$ for 5 minutes after brushing teeth, $5.25{\pm}0.56$ for 10 minutes after brushing teeth, $5.29{\pm}0.62$ for 15 minutes after brushing teeth, $5.34{\pm}0.58$ for 20 minutes after brushing teeth, $5.40{\pm}0.53$ for 25 minutes after brushing teeth, and $5.61{\pm}0.59$ for 30 minutes after brushing teeth. 3. Stimulated salivary and non-stimulated salivary flow rate, salivary viscosity, and salivary buffering capacity were indicated to be higher in group with non-caries than group with caries. However, it was statistically insignificant. The hydrogen ion concentration in dental plaque showed wholly statistical significant in the relationship with people with dental caries under progression. However, people without dental caries were indicated to be higher than people with dental caries. 4. As for correlation between caries activity test methods, the stimulated salivary flow rate had significantly positive correlation with non-stimulated salivary flow rate(p<0.001). Non-stimulated salivary flow rate showed negative correlation with salivary buffering capacity(p<0.01). The hydrogen ion concentration test in dental plaque showed positive correlation according to the passage of time after brushing teeth. However, there was no significant correlation with salivary viscosity and salivary buffering capacity(p>0.05).

• Korean Journal of Poultry Science
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• v.29 no.4
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• pp.249-253
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• 2002

A 2 ${\times}$ 2 factorial experiment was conducted to determine the effect of cecectomy and urea supplementation on nitrogen utilization In growing chicks. Birds were either cecectomized or shamoperated and fed a 19% protein diet with or without 1% urea supplementation. All chicks were provided ad libitum access to feed and water throughout the six-day experimental period. In the cecectomized chicks, fred efficiency was significantly decreased when fed a 19% protein diet supplemented with 1% urea (P<0.05). When chicks were fed a 19% protein diet, cecectomy significantly shortened gastrointestinal passage time (GPT) of food (P<0.05). However, the GPT was significantly lengthened in chicks fed a 19% protein diet supplemented with urea (P<0.05). Regardless of diets, cecectomized chicks increased the moisture contents of the excreta (P<0.05) and feeding a 1% dietary urea also significantly increased (P<0.05). Cecectomy significantly decreased uric acid N excretion by about 30 mg per 100 g body weight per day (P<0.05) and uric acid N/ total N excretion when fed both diets (P<0.05). The present study suggests that cecectomy improves nitrogen utilization rate by decreasing uric acid excretion in growing chicks. These results are in good agreement with those obtained previously in a cecectomy study of adult chickens.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.5
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• pp.666-673
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• 2016

Two experiments were conducted to evaluate the effects of the level of corn dry distillers grains with solubles (CDDGS) supplementation on growing performance, blood metabolites, digestion characteristics and ruminal fermentation patterns in steers grazing dormant forage. In Exp. 1, of growth performance, 120 steers ($204{\pm}5kg$ initial body weight [BW]) were distributed randomly into 3 groups (each of 40 steers), which were provided with the following levels of CDDGS supplement: 0%, 0.25%, or 0.50% BW. All groups of steers were grazed for 30 days in each of 3 grazing periods (March, April, and May). Approximately 1,000 ha of the land was divided with electric fencing into 3 equally sized pastures (333 ha in size). Blood samples were collected monthly from 20 steers in each grazing group for analysis of glucose (G), urea-nitrogen (UN) and non-esterified fatty acids. Final BW, average daily gain (ADG) and supplement conversion (CDDGS-C) increased with increasing levels of CDDGS supplementation (p<0.05).The CDDGS supplementation also increased the plasma G and UN concentrations (p<0.05). In Exp. 2, of digestive metabolism, 9 ruminally cannulated steers ($BW=350{\pm}3kg$) were distributed, following a completely randomized design, into groups of three in each pasture. The ruminally cannulated steers were provided the same levels of CDDGS supplementation as in the growing performance study (0%, 0.25%, and 0.50% BW), and they grazed along with the other 40 steers throughout the grazing periods. The dry matter intake, crude protein intake, neutral detergent fiber intake (NDFI), apparent digestibility of dry matter (ADDM), crude protein (ADCP) and neutral detergent fiber (ADNDF) increased with increasing levels of CDDGS supplementation (p<0.05). The ruminal degradation rates of CP (kdCP), NDF (kdNDF) and passage rate (kp) also increased with increasing levels of CDDGS supplementation (p<0.05). Ruminal ammonia nitrogen ($NH_3$-N) and propionate concentrations also increased with increasing levels of CDDGS supplementation (p<0.05). However, acetate concentrations decreased with increasing levels of CDDGS supplementation (p<0.05). Liquid dilution rate increased with increasing levels of CDDGS supplementation but ruminal liquid volume decreased (p<0.05). On the basis of these findings, we can conclude that CDDGS supplementation enhanced the productive performance of cattle grazing native rangeland without negatively affecting forage intake, glucose and urea-nitrogen blood concentrations, ruminal degradation and ruminal fermentation patterns.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.73.2-74
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• 2015

The gas cloud G2 falling toward Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way, is supposed to provide valuable information on the physics of accretion flows and the environment of the black hole. We observed Sgr A* with four European stations of the Global Millimeter Very Long Baseline Interferometry Array (GMVA) at 86 GHz on 1 October 2013 when parts of G2 had already passed the pericenter. We searched for possible transient asymmetric structure - such as jets or winds from hot accretion flows - around Sgr A* caused by accretion of material from G2. The interferometric closure phases (which are zero if the spatial brightness distribution of the target is symmetric, and deviate from zero otherwise) remained zero within errors during the observation time. We thus conclude that Sgr A* did not show significant asymmetric (in the observer frame) outflows in late 2013. Using simulations, we constrain the size of the outflows that we could have missed to ${\approx}2.5$ mas along the major axis, ${\approx}0.4$ mas along the minor axis of the beam, corresponding to approximately 232 and 35 Schwarzschild radii, respectively; we thus probe spatial scales on which the jets of radio galaxies are suspected to convert magnetic into kinetic energy. As probably less than 0.2 Jy of the flux from Sgr A* can be attributed to accretion from G2, one finds an effective accretion rate ${\eta}M{\leq}1.5{\times}10^9kg/s{\approx}7.7{\times}10^{-9}M_{earth}/yr$ for material from G2. Exploiting the kinetic jet power-accretion power relation of radio galaxies, one finds that the rate of accretion of matter that ends up in jets is limited to $M{\leq}10^{17}kg/s{\approx}0.5M_{Earth}/yr$ less than about 20% of the mass of G2. Accordingly, G2 appears to be largely stable against loss of angular momentum and subsequent (partial) accretion at least on time scales ${\leq}1$ year.

• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.791-798
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• 1994

Ohmic heating is a food processing operation in which heat is internally generated within foods by the passage of alternating electric current. The process enables highly viscous paste foods such as Kochujang, and fermented soybean paste to be heated very fast. In order to develope the novel pasteurization process of paste foods, static Ohmic heating system was built, and heating characteristic during Ohmic heating under various conditions were studied. Electric conductivities of Kochujang and fermented soybean paste at room temperature were 1.865 S/m and 2.510 S/m, respectively and increased linearly with increasing temperature. Specific heating rate was highly dependent on the frequency. The highest heating rate was achieved at 5 KHz for Kochujang and 20 KHz for fermented soybean paste. Uniform heating throughout the sample was achieved during Ohmic heating with low frequency electrical currents, however above 5 KHz frequency, surface temperature was several degrees higher than the bulk.

• Journal of Veterinary Clinics
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• v.23 no.3
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• pp.223-229
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• 2006

Recently canine parvovirus(CPV) enteritis had been controlled successfully by the use of low-passage high titer modified live CPV vaccines. However, outbreaks of CPV enteritis have been continued in Korea. In this study, we carried out epidemiological investigation on the recent outbreaks of CPV enteritis of dogs and determined the potential prognostic factors affecting the survival of dogs. The total of 140 dogs diagnosed for CPV enteritis were statistically analysed. The majority of dogs were from 6 to 18 weeks of age and were not vaccinated or incompletely vaccinated. There were significant difference in the survival rate between male and female dogs with CPV enteritis and among the age groups(p<0.05). Moreover, there was significant difference in the survival rate of dogs between HI titer <80 group and HI titer 160 group(p<0.05). The majority of dogs had a history of diarrhea, vomiting, lethargy and dehydration. It was considered that recent outbreak of CPV enteritis in Korea caused by the failure of vaccination and/or by the inadequate antibody responses to CPV vaccines. Prophylactic measures should include isolation of young dogs from the dog population until the vaccination can be expected to provide protection.

• Reproductive and Developmental Biology
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• v.30 no.2
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• pp.119-124
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• 2006

The present study compared the developmental potential of cloned porcine embryos with mesenchymal stem cells (MSCs), fetal fibroblasts (FFs) and cumulus cells (CCs) by assessing the cleavage and blastocyst rate, total cell number, inner cell mass (ICM) ratio and apoptosis. MSCs were isolated by ficoll gradients from femur of -6 month old female pig, and maintained for primary cultures. FFs from a female fetus at ${\sim}30$ day of gestation were established, and CCs were obtained from cumulus oocyte complexes (COCs) aspirated from $3{\sim}6$ mm follicles in diameter. Donor cells at $3{\sim}4$ passage were employed for nuclear transfer (NT). COCs were matured and fertilized in vitro(IVF) as control. Cleavage rate was significantly (P<0.05) higher in IVF than in NT embryos with MSCs, FFs and CCs ($82.7{\pm}8.9%\;vs\;70.6{\pm}5.4,\;68.7{\pm}5.1\;and\;63.4{\pm}5.6%$, respectively). However, blastocyst rates in IVF and NT embryos derived from MSCs ($24.5{\pm}2.8\;and\;20.4{\pm}8.3%$) did not differ, but were significantly (P<0.05) higher than NT derived from FFs and CCs ($10.6{\pm}2.7\;and\;9.8{\pm}2.1%$). Total cell number and the ratio of ICM to total cells among blastocysts cloned from MSCs ($35.4{\pm}5.2\;and\;0.40{\pm}0.09%$, respectively) were significantly (P<0.05) higher than those from FFs and CCs ($24.9{\pm}6.2%\;vs\;0.19{\pm}0.16,\;23.6{\pm}5.5\;and\;0.17{\pm}0.16%$, respectively). Proportions of TUNEL positive cells in NT embryos from FFs and CCs ($6.9{\pm}1.5\;and\;7.4{\pm}1.7%$, respectively) were significantly (P<0.05) higher than in MSCs ($4.8{\pm}1.4%$) and IVF ($2.3{\pm}0.9%$). The results demonstrate that MSCs have a greater potential as donor cells than FFs and CCs in achieving enhanced production of cloned porcine embryos.