• Applied Chemistry for Engineering
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• v.17 no.3
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• pp.250-254
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• 2006

Reaction of $CO_2$ with $Li_{2}ZrO_{3}$ has been investigated in a TGA and the effects of $H_{2}$ and CO on the removal of $CO_{2}$ using $Li_{2}ZrO_{3}$ were evaluated in a packed bed reactor. The initial rate of $CO_{2}$ removal reaction of $Li_{2}ZrO_{3}$ increased with the increase of gas flow rate up to 100 mL/min and then was maintained, which implied the disappearance of the gas film resistance. The reaction of $CO_{2}$ with $Li_{2}ZrO_{3}$ took place as the first order and the range of optimum temperature was found to be about $500{\sim}600^{\circ}C$. XRD and SEM analysis showed the formation of crystalline $Li_{2}ZrO_{3}$ and porous $Li_{2}ZrO_{3}$/$ZrO_{2}$. The presence of $H_{2}$ did not affect the adsorption of $CO_2$ with $Li_2ZrO_3$. On the other hand, CO inhibited the sorption of $CO_{2}$ into $Li_{2}CO_{3}$(L) on $Li_{2}ZrO_{3}$.

• Land and Housing Review
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• v.15 no.2
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• pp.107-124
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• 2024

Based on Muan-gun, Jeollanam-do, this study explores how to mitigate the disappearance of rual areas. The study surveyed 95 young farmers in Muan-gun to assess their farming practices and the challenges they face. We further employ factor analysis and cluster analysis classify young farmers in Muan-gun, facilitating the identification of tailored policies or initiatives aimed at fostering and supporting young farmers. The results are summarized as follows. First, Muan County does not have any ordinances or original projects specifically designed to support young farmers. Second, the succession rate of farmland among young farmers in Muan County is 41.1%, which is comparable to the national rate of 43.7%. This indicates that approximately 40% of young farmers in Korea have inherited farmland, a critical foundation for agricultural activities. Third, despite accumulating farming experience, young farmers have not seen any improvement in local living conditions, and rather their difficulties have intensified. Fourth, this study conducted a factor analysis using 21 variables, resulting in the selection of seven common factors for cluster analysis. Consequently, young farmers in Muan County were categorized into three groups. The multinomial logit analysis revealed that the typology of young farmers is influenced by indicators such as cultivated area, farming experience, demand for smart farms, farm income, and farming type (rice cultivation or other). Therefore, to attract young farmers and prevent the decline of rural areas, policy efforts should focus on minimizing entry barriers to farming infrastructure, such as access to farmland, and improving local settlement conditions.

• The Korean Journal of Physiology
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• v.1 no.1
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• pp.33-41
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• 1967

The metabolic patterns of C-1 and C-6-carbon atoms of glucose were observed in the tissue homogenates of the Ehrlich ascites tumor tissue which was incubated for 3 hours in the Dubnuff metabolic shaking incubator. $C^{14}-1-and\;C^{14}-6-glucose$ were used as tracers. The glucose media in which tissue homogenate was incubated was kept at a concentration of 200mg% glucose of carrier and appropriate amount of $C^{14}-1-or\;C^{14}-6-tracer$. At the end of 3 hour incubation, respiratory $CO_2$ samples trapped by alkaline which is placed in the tenter well of incubation flask were analyzed for the total $CO_2$ production rates and their radioactivities. The tissue homogenate samples after incubation were analyzed for their concentrations of glucose, lactate, pyruvate and glycogen and calculations were made on the glucose consumption rate, pyruvate and lactate accumulation rates. The following results were obtained. Data obtained in each group are as follows: 1. In the tissue homogenate, which was incubated with $C^{14}-1-glucose as a substrate, total $CO_2$ production rate averaged $19.0{\pm}5.0{\mu}M/hr/gm$ and the mean specific activity of respiratory $CO_2$ was $840{\pm}296\;cpm/mgC.$ Relative specific activity (RSA) which means the fraction of $CO_2$ derived from medium $C^{14}-1-glucose$ to total $CO_2$ production rate was calculated by ratio of SA of respiratory $CO_2$ and medium $C^{14}-1-glucose.$ RSA was $14.3{\pm}5.0%,$ Accordingly actual $CO_2$ production rate from medium $C^{14}-1-glucose$ showed a mean value of $2.79{\pm}1.35\;{\mu}m$ of which amount was equivalent to the mean value of total glucose consumption rate $(RGDco_2)$, namely, $5.1{\pm}1.3%.$ Lactate and pyruvate appearance rates averaged $7.13{\pm}1.26\;and\;0.21{\pm}0.02{\mu}M/hr/gm,$ respectively. Assuming that these 3 carbon compounds appeared in the medium were derived from glucose, calculations were made that relative glucose disappearance rate into lactate $(RGD_L)$ was $38.0{\pm}5.4%\;and\;RGD_P$ was $1.23{\pm}0.03%.$ Therefore, about 43.3% of the total glucose consumed were accounted for by conversion into the respiratory $CO_2$, lactate and pyruvate. 2. In the second group, which was incubated with $C^{14}-1-glucose$ as a substrate, glucose consumption rate, lactate and pyruvate appearance rates showed almost the same order as the values of the $C^{14}-1-glucose$ substrate group. However, RSA was remarkably decreased showing a mean value of $1.02{\pm}0.13%.$ This fact means that the C-6 carbon of glucose take the minor part in the oxidative metabolism of glucose. The glycogen level in both substrate tissue homogenate showed less than 0.3% of tissue weight. These low value suggested that there was an inhibition of carbohydrate synthesis in the Ehrlich ascites tumor tissue. 3. The catabolic pathway of glucose in the tumor tissue were analyzed on the basis of Bloom's principle from the values of RSA. It was found that in the tumor tissue more than 90% of $CO_2$ derived from glucose were oxidized via the alternate pathway other than principal EMP-TCA cycle such as hexose monophosphate pathway (HMP). From the data described above, it was assumed that in the Ehrlich tumor tissue anaerobic glycolysis proceeds normally although, the oxidation of products of anaerobic glycolysis via the TCA cycle is inhibited resulting in the accumulation of lactate and almost all of oxidative energy from glucose is released by oxidative pathway such as HMP.

• Journal of Life Science
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• v.18 no.11
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• pp.1561-1569
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• 2008

This study was conducted to investigate the effects of steam flaking of corn grains on in situ dry matter degradability in the rumen and contents of mycotoxins (aflatoxin, ochratoxin) during storage. Yellow dent corns imported from USA and India were flaked, and stored for 8 weeks under the standard temperature and pressure (STP; $25^{\circ}C$/ 1 atm.). Experimental treatments were composed of four corn grains (untreated-USA corn, USCW; steam flaked-USA corn, USCF; untreated-India corn, IDCW; steam flaked-India corn, IDCF) with 4 replications according to 9 storage periods (0, 1, 2, 3, 4, 5, 6, 7, 8 week). Two ruminally cannulated Holstein bulls were used for in situ trial. Pathogen contamination trial was performed by comparing the mycotoxin contents in corns during storage periods. Dry matter disappearance rate in the rumen was about 3.0 to 44.1% higher (P<0.05) for USCW than IDCW, but was not difference between USCF and IDCF. With steam flaking of corn, dry matter degradability in the rumen was significantly (P<0.05) increased in corn from India, but was not affected in corn from USA. Aflatoxin content was very low level in corns from USA and steam flaked corns, but was higher than the tolerance limit of domestic aflatoxin content regulation when IDCW was stored over 6 week under STP. Ochratoxin content was low level in all treatments. From above results, it is reasonable that the corn imported from India might be flaked for enhance the ruminal DM degradability and safe from aflatoxin pathogen.

• Journal of agriculture & life science
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• v.50 no.5
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• pp.139-152
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• 2016

The comparative in vitro and in situ analysis were conducted to evaluate the rumen degradability and physical structure of domestic roughage as rice straw, timothy, alfalfa, wormwood and green tea. The feedstuffs incubated with rumen fluid and was used to determine gas production, microbial growth rate and pH changes in an in vitro experiment. The gas production was increased during incubation times and was significantly(p<0.05) lower in green tea than other feedstuffs. The microbial growth rate in the feedstuffs was increased during incubation times. However, microbial growth rate was significantly(p<0.05) lower in wormwood and green tea than other feedstuffs. Ruminal pH was decreased during incubation times, and timothy was the lowest, and rice straw was the highest among feedstuffs. The disappearance rate of dry matter(DM) and crude protein(CP) in all feedstuffs were increased during incubation times and green tea was the highest(p<0.05) compared with other feedstuffs. In effective degradability, when rumen out-flow rate was assigned to 4%, wormwood showed the highest in DM, and alfalfa was the highest in CP. Whereas, green tea was the highest in both in situ DM and CP degradability. Many cilia on the surface and stoma of wormwood and stoma in green tea were observed by scanning electron microscopy. Microbes breaked down the cilia at the beginning and then degraded the surface in wormwood. In case of green tea, microbes attached to stoma. Therefore, wormwood and green tea have a potential value as ruminal feed stuffs.

• The Korean Journal of Physiology
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• v.21 no.2
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• pp.241-257
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• 1987

The effects of external $Ca^{2+}$ and $Ca^{2+}-antagonists$ on the spontaneous contractions and electrical activities were investigated in guinea-pig stomach in order to clarify the mechanism for the generation of slow waves. Electrical responses of circular smooth muscle cells were recorded using glass capillary microelectrodes filled with 3 M KCl. All experiments were performed in tris-buffered Tyrode solution which was aerated with 100% $O_2$ and kept at $35^{\circ}C$. The results obtained were as follows: 1) The amplitude of spontaneous contractions was maximal at around 2-4 mM $Ca^{2+}$, whereas their frequency was inversely related with external $Ca^{2+}$ within the range of 0.5 to 16 mM $Ca^{2+}$. 2) Verapamil suppressed the amplitude of spontaneous contraction in a dose-dependent manner, while the frequency of spontaneous contractions was almost not changed over the whole concentration of verapamil $(0.01{\sim}5\;mg/l)$. 3) Manganese increased both the amplitude and the frequency of spontaneous contractions dose-dependently in low $Mn^{2+}$ (below 0.05 mM $Mn^{2+}$), while their amplitude and frequency were decreased in high $Mn^{2+}$ (above 0.1 mM $Mn^{2+}$). 4) The ampltude and maximum rate of rise of slow waves were incrased in high $Ca^{2+}$ solution. In $Ca^{2+}-free$ solution, the spontaneous contractions recorded simultaneously with slow waves ceased and tonic contraction ($Ca^{2+}-free$ contracture) was developed in parallel with membrane depolarization and the disappearance of slow waves. 5) Verapamil (1 mg/1) decreased the amplitude and maximum rate of rise of slow waves and it depolarized the membrane by about 6 mV, whereas the frequency of slow waves was not affected by verapamil. 6) Manganese showed different characteristic effects between low and high $Mn^{2+}$ on the slow waves: In low $Mn^{2+}$ (0.05 mM $Mn^{2+}$), the initial rapid increases and the subsequent gradual decreases in three parameters of slow waves (amplitude, rate of rise, and frequency of slow waves) till a new steady state were observed. However, in high $Mn^{2+}$ (0.5 mM $Mn^{2+}$) slow waves disappeared and membrane was depolarized. From the above results, the following conclusions could be made: 1) $Ca^{2+}$ is necessary for a generation of the slow waves, even though it is small amount. 2) Verapamil suppresses the spontaneous contractions of gastric antral strip by the decreases in amplitude and maximum rate of rise of slow waves, while this drug does not block the $Ca^{2+}-channel$ involved in the generation of slow waves. 3) Manganese has dual actions on the $Ca^{2+}-channels$; the $Ca^{2+}-channel$ involved in the generation of slow waves (or Na-Ca exchange system) or the channel for the generation of spike potentials are stimulated by a low concentration of $Mn^{2+}$, while both the $Ca^{2+}$. Channels are blocked by high concentration of $Mn^{2+}$.

• Childhood Kidney Diseases
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• v.2 no.2
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• pp.110-117
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• 1998

Purpose : Henoch-$Sch{\ddot{o}}nlein$ purpura nephritis(HSPN) accompanied by nephrotic syndrome(NS) is known to have a poor prognosis and effective treatment is still controversial, even though both corticosteroids and immunosuppresant have been used for therapy. Cyclosporine A(CsA) is a well known immunosuppresant and widely used in renal transplantation and glomerular diseases especially steroid resistant. The aims of this study was to evaluate the therapeutic effect of CsA and to compare CsA with previously reported our data of rifampin(RFP) and azathioprine(AZA) in children with HSPN accompanied by NS. Methods : 37 HSPN patients with NS confirmed by renal biopsy were selected. Of these, 17 patients were treated with CsA(5 mg/kg/day) fur 6-8 months, 7 children were treated with RFP(10-20 mg/kg/day) for 9-12 months and 13 patients were treated with AZA(2 mg/kg/day) fur 8 months. Along with these regimens, low dose oral prednisolone(0.5-1 mg/kg, qod) was also used. Sequential renal biopsy was done in all patients 1 month after termination of treatment. Results : Complete remission rate of nephrotic syndrome was $58.8\%$ in CsA, $57.1\%$ in RFP and $38.4\%$ in AZA group after 17, 22, 11 months of mean follow-up period. Overall remission rate including partial remission was $88.2\%$ in CsA, $85.7\%$ in RFP and $84.6\%$ in AZA group. Disappearance rate of hematuria was $58.8\%$ in CsA, $57.1\%$ in RFP and $46.2\%$ in AZA group. Improvement of grade of clinical status was observed in 17 out of 17 CsA, 7 out of 7 RFP and 10 out of 13 AZA group. Improvement of pathologic class on sequencial renal biopsy was shown in 5 CsA($29.4\%$), none RFP($0\%$) and 2 AZA group($12.4\%$). Improvement on histologic immune-deposition was seen in 15 CsA($88.2\%$), 6 RFP($85.9\%$) and 4 AZA group($30.8\%$). Conclusion : In conclusion, Both CsA and RFP treated groups showed better result in complete remission rate of nephrotic syndrome and significant improvement of histologic immune-deposition compared with AZA treated group(p=0.004). So, we recommend CsA and REP rather than AZA for immunosuppresant treatment in HSPN with nephrotic syndrome.

• The Korean Journal of Physiology
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• v.7 no.1
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• pp.23-31
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• 1973

Numerous factors concern with the absorption of substances through the membrane of the gastrointestinal tract. To simplify the experimental condition, present work has been restricted to observe the disappearance rate of substance from the intestinal loop which was made in the jejunum, 70 cm apart from the pylorus of the adult rabbit. The purpose of the study is to clarify the absorption of urea through the jejunal wall is solely attributable to the concentration difference between the luminal fluid and plasma, and to observe the effect of adding red pepper upon the rate of absorption. The rabbits were anesthetized with nembutal, 35mg/kg I.V. Jejunal loop was made by ligating at 2 spots, 70 cm and 80cm apart from the pylorus. After rinsing with normal saline solution through the polyethylene tubing inserted from the end of the loop, 8 ml of test solution was placed through the same tubing. The test solution contained 200 mg% of urea and 150mg% of polyethylene glycol(M.W. 4,000) in normal saline solution. Right after placing the test solution the first specimen was taken through the tubing, and successive samplings were performed at 5, 10, 20, and 30 minutes. Logarithm of the difference of urea concentration between the luminal fluid and plasma was plotted against time elapsed after the onset of the experiment. If straight line is revealed, it would verify the nature of transport mechanism as diffusion, obeying the Fick's principle. The concentration of polyethylene glycol (PEG) was also measured in order to examine the change in the volume. PEG was used as the marker substance because it is not absorbable in the intestinal tract. Consequently the concentration of PEG relates inversely to the volume of the loop. Instantaneous concentration of urea in the loop times the volume will give the amount of urea remaining in the luminal fluid. The change in the amount of any substance is directly relate to the volume of the compartment and differs from the change in the concentration which is independent of the volume. After completion of the experiment without red pepper, it was added in the test solution and was centrifuged after thorough mixing. Supernatant of the mixture was placed in the loop and similar sampling were performed with the same time intervals that of previous run in order to observe the effects of the red pepper on the passive transport of the water soluble small substance, urea. The results obtained were as follows: 1. Logarithm of the concentration difference of urea between the luminal fluid and plasma was diminished exponentially as time elapsed. The decay constant in the experiment without red pepper was 0.0563/min. By adding red pepper in the test solution as much as the concentration rose to 4,000 mg% and 8,000 mg%, the decay constants were lowered to 0.0493/min and to 0.0506/min, respectively. The time interval by which the concentration difference dropped to one half of the initial value was prolonged. Without red pepper the half concentration time was 13.30 minutes, and by adding extract of red pepper, 15.31 minutes and 15.71 minutes were revealed. 2. The profile of the diminishing rate of tile amount of urea was quite different from that of the concentration because of the change in the volume of the loop during the observed period. 3. By adding the extract of red pepper, it slowed down the rate of absorption of urea in the intestinal loop, suggesting an increase in the diffusional barrier. 4. Larger dosage of red pepper brought an increase in the secretion of intestinal fluid with concomitant expansion of the luminal volume, and the retardation of the absorption of urea was noticed. This effect was largely dependent on the sensitivity of the individual animal to the red pepper, extract. The amount of urea remained after 10 minutes interval was 55.5% of the initial amount in the experiment without red pepper. On the other hand it was not consistent after administration of red pepper, showing 50.6% and 66.5% of the initial figures by adding 400 mg and 800 mg of red pepper in the test solution, respectively. It was postulated that symptom of diarrhea often encountered by taking a hot (red pepper) food might be attributable to the increase of secretion and the retardation of absorption in the intestinal tract.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.11
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• pp.1593-1598
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• 2003

Nutritional evaluation of some agro-industrial byproducts available in Samoa [dry brewers' grains (DBG), cocoa shell (CS), cocoa dust (CD) and desiccated coconut waste meal (DCWM)] available in Samoa was carried out using both the in vivo and in vitro techniques. In the in vivo study 24 Anglo-nubian goats were offered by-products with other feed ingredients to compound four different diets. The goats were randomly allocated to 4 diets on the basis of liveweight (18.7-0.3kg). The ADF content of the byproducts followed a similar trend to NDF. The byproducts have a high content of organic matter (91.0-95.4%). Gross energy (GE) content was higher in DCWM (25.1 MJ/kg DM), closely followed by CD (23.2 MJ/kg DM). Concentrate intake was significantly different (p<0.05) among the goats. Average daily live weight gains were 105, 92, 88 and 97 g/goat/day for DBG, CS, CD and DCWM, respectively. Daily live weight gains were higher (p<0.05) in the goats that received DBG, while the least gain was obtained in the goats that received CS byproduct diet. DM digestibility was significantly higher (p<0.05) in the goats on DBG diet than in the other goats. The least DM digestibility was obtained in the goats that received CD diet (p>0.05). CP digestibility followed a similar pattern to DM digestibility. The digestibility of NDF and ADF was influenced by the nature of the diets. The digestibility of OM and GE were best (p<0.05) in the goats that received DBG, DCWM and CS byproduct diets than in CD. Significant differences (p<0.05) among the byproducts were recorded for net gas production. Potential gas production (a+b) ranged from 7.064 to 42.17 ml. Organic matter digested (OMD) from gas production value at 24 h was higher in DBG (47.6 g/kg DM) and this was followed by DCWM (42.5 g/kg DM). The least OMD was obtained in CD (17.9 g/kg DM). A significant difference (p<0.05) in DM disappearance after 4, 8, 16, 24, 48 and 72 h was recorded. The potential and effective degradability varied significantly (p<0.05) from 85.95-99.6 g/kg DM and from 39.9-65.8%, respectively. The digestibility of the byproducts in both the in vivo and in in vitro techniques demonstrated that they are potential source of feed ingredients for ruminant livestock in Samoa and possibly in the other small Pacific Island countries. On the basis of their potential degradability the byproducts could be ranked in the following order:DCWM>DBG>CD>CS. In conclusion, the results obtained suggest that all the byproducts can contribute to ruminant livestock diets without adverse effects on feed intake, growth rate and apparent nutrient digestibility coefficients.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.3
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• pp.354-362
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• 2018

Objective: Wheat is an alternative to corn silage for ruminant feeding in northern China. This study examined the effects of harvest time and added molasses on nutritional content, ensiling characteristics and in vitro degradation of whole crop wheat (WCW). Methods: Fresh WCW at the milk-ripe stage was harvested at 0700 h (i.e., in the morning [Mo]) and 1700 h (i.e., in the afternoon [Af]), and then immediately used to prepare silage and make hay. Commercial molasses was added to Af WCW at 0%, 2%, 4%, and 6% (fresh weight) proportions. The WCW treated with molasses was mixed thoroughly prior to ensiling. Results: Dry matter (DM), neutral detergent fiber, water soluble carbohydrate (WSC) content (p<0.01), accumulative gas production in 72 h ($GP_{72h}$, 77.46 mL/g vs 95.15 mL/g) and dry matter disappearance in vitro (69.15% vs 76.77%) were lower (p<0.05), while crude protein (CP) content was higher for WCW silage (WCWS) compared to WCW (p<0.01). The propionic acid and butyric acid concentrations in WCWS from Mo WCW were 1.47% and 0.26%, respectively. However, the propionic and butyric acid concentrations were negligible, while the ammonia nitrogen/total nitrogen ($NH_3-N/TN$, p<0.01) concentration was lower and the rate of gas production at 50% of the maximum (17.05 mL/h vs 13.94 mL/h, p<0.05) was higher for Af WCWS compared to Mo WCWS. The incubation fluid's $NH_3-N$ concentration was lower in WCWS and Af WCW compared to Mo WCW (p<0.05). The CP and WSC content increased with increasing molasses levels (p<0.05). Furthermore, the pH (p<0.01) and time when gas production was 50% of the maximum (2.78 h vs 3.05 h, p<0.05) were lower in silage treated with 4% molasses than silage without molasses. Conclusion: Harvesting wheat crops in the afternoon and adding molasses at 4% level to WCW optimally improved ensiling characteristics, leading to well-preserved silage.