• KSBB Journal
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• v.23 no.5
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• pp.452-459
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• 2008

To obtain maximal efficacy with minimal systemic side-effects, many studies have been carried out to achieve the controlled release of 5-fluorouracil (5-FU). In this study, biodegradable poly(L-lactide) (L-PLA) microparticles containing 5-FU were prepared by a process, called aerosol solvent extraction system (ASES), utilizing supercritical carbon dioxide. The effects of various organic solvents, drug/polymer feeding ratio, polymer molecular weight, and blending with the same polymers with different molecular weights on the formation of 5-FU loaded microparticles were investigated under a predetermined operating condition from our previous study. The drug recovery, entrapment efficiency, and in vitro drug release kinetics were determined by HPLC assays. The drug recovery obtained from the ASES process was found to be very high, whereas the drug entrapment efficiency was considerably low in all the experiments due to the poor affinity between L-PLA and 5-FU. These results indicated that the precipitation rate of L-PLA might be quite different from that of 5-FU so that there was little chance to form 5-FU loaded L-PLA microparticles.

• Resources Recycling
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• v.26 no.5
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• pp.54-60
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• 2017

In this study, we investigated the effect of $TiCl_4$ injection time on the Kroll reaction at a given weight ratio of $TiCl_4$ and Mg. The reduction reaction was investigated by measuring the temperature change according to $TiCl_4$ injection time and observing the cross section and appearance of the Ti sponge after the reaction. The temperature increment due to Kroll reaction heat generation was found to be linearly proportional to the $TiCl_4$ feed rate. In the graph of $TiCl_4$ injection time and reduction tank temperature, initial temperature peaks were observed irrespective of the injection conditions. This is interpreted to mean a temporary interruption of reaction due to $MgCl_2$ formation after the initial Kroll reaction. In addition, when the cross section of the sponge was observed, a large amount of spherical Mg particles was observed in $MgCl_2$. We can infer that this is the process of continuously feeding the unreacted Mg surface, so that a continuous Kroll reaction takes place. The sponge appearance showed that the coalescence or growth of the Kroll reacted Ti particles can be controlled by the cooling rate.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.5
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• pp.783-787
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• 1999

To study the effects of different extrusion conditions of barley on growth performance, nutrient digestibility and nutrient excretion in feces, a total of 150 growing pigs ($Landrace{\times}Duroc{\times}Large$ White; average 24.4 kg body weight) were allotted to five treatments, in a completely randomized block design. The experimental diets were based on corn-soybean and 30% of barley was included in each diet; barley was the only extruded ingredient. The treatments were 1) no extrusion (Control); 2) extrusion at $100^{\circ}C$ without preconditioning (ENLT); 3) extrusion at $150^{\circ}C$ without preconditioning (ENHT); 4) extrusion at $100^{\circ}C$ with preconditioning (ECLT); 5) extrusion at $150^{\circ}C$ with preconditioning (ECHT). Temperature in the barrel was controlled within ${\pm}5^{\circ}C$ by feed rate with the addition of water at the rate of $3{\ell}\;per\;min$. in the extruder for each treatment. For the 6 week experimental period, extrusion of barley improved the average daily gain (ADG) and digestibilities of dry matter, crude protein and gross energy in growing pigs. As compared to control, significant improvements in ADG (p<0.05) were shown in the groups of feeding extruded barley at high temperature (ENHT and ECHT). There were also significant differences in the digestibilities of DM, CP and P between extrusion temperatures. Barley extruded at high temperature gave better digestibilities of DM, CP and GE than barley extruded at low temperature. Extruded barley diet groups showed significantly (p<0.05) lower excretions of DM, nitrogen (N) and P per kg gain as compared to the ground barley group. DM, N and P excretion per kg gain were also significantly lower in pigs fed barley extruded at $150^{\circ}C$ than at $100^{\circ}C$. In conclusion, extrusion considerably improved the nutritive value of barley and it appeared that temperature is the most important variable.

• Journal of Animal Science and Technology
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• v.62 no.4
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• pp.485-494
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• 2020

Limiting amino acids (AAs) for milk production in dairy cows fed on a concentrate diet of corn grain and soybean meal was evaluated in this study. Four lactating and multiparous Holstein cows (in third or fourth parities, with an average body weight of 633 ± 49.2 kg), 8 to 9 weeks into their lactation period, were used in a 4 × 4 Latin square design. The experiment comprised four dietary treatments: (1) no intravenous infusion (control); (2) control plus intravenous infusion of an AA mixture of 6 g/d methionine, 19.1 g/d lysine, 13.8 g/d isoleucine, and 15.4 g/d valine (4AA); (3) control plus intravenous infusion of the AA mixture without methionine (no-Met); and (4) control plus intravenous infusion of the AA mixture without lysine (no-Lys). All animals were fed on a controlled diet (1 kg/d alfalfa hay, 10 kg/d silage, 14 kg/d concentrate mixture, ad libitum timothy hay). The AA composition of the diet and blood were determined using an automatic AA analyzer. Milk composition (protein, fat, lactose, urea nitrogen, and somatic cell counts) was determined using a MilkoScan. The results showed that feed intake for milk production did not differ from that of intravenous infusion using a limiting AA mixture. The 4AA treatment numerically had the highest milk yield (32.4 kg/d), although there was no difference when compared with the control (31.2 kg/d), no-Met (31.3 kg/d), and no-Lys (31.7 kg/d) treatments. The concentration of AAs in blood plasma of cows in all treatments, mainly isoleucine and valine, increased significantly compared with that of control. The no-Met treatment increased (p < 0.05) the concentration of lysine in the blood relative to the control and no-Lys treatments, whereas the no-Lys treatment increased (p < 0.05) the concentration of methionine relative to the control and no-Met treatments. In conclusion, milk production increased when feeding 10 g/d methionine to the cows, together with their concentrate diet of corn grain and soybean meal.

• Korean journal of applied entomology
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• v.62 no.3
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• pp.139-147
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• 2023

Leaf-spray in vitro bioassays appraise new aphicidal formulations for managing deleterious plant-feeding aphids. The formulation may utilize alternative and integrated strategies. However, leaf spraying even under controlled conditions may affect aphid reproduction and mortality. This study examines leaf spray applications for optimum and reproducible aphicidal results using tobacco leaves overlaid on cotton fabric or water agar surfaces. Infestation of the undersides of tobacco leaves with nymphs of green peach aphids was used in the assays. Spray distance and volume were optimized using water-sensitive paper to ascertain the best surface coverage. Overlays of the leaves on water agar caused less mortality and greater reproduction than the use of cotton fabric. The relative humidity of the insect-rearing chambers changed with the watering regime for the insect - rearing chambers with cotton fabric; 60% relative humidity was optimal. Relative humidity was not affected by the concentration of agar in the water agar chambers. Applications of the chemical aphicidal standard, Sulfoxaflor, under the optimized conditions exhibited similar times for lethality although the rate was faster with leaves on the cotton fabric than on water agar. These studies establish reproducible and sensitive techniques for assessing the lethality and effects on reproduction of potential aphicidal products.

• Journal of Life Science
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• v.16 no.6
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• pp.942-948
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• 2006

This study was performed to determine whether the length of the feeding of the controlled experimental diet to the dam resulted in changes to the dam milk or pup brain fatty acid composition. As a first method, females have been obtained at 3 weeks of age and fed the experimental diet throughout their growth to adulthood including mating, pregnancy, and lactational periods. As a second method, in order to shorten this long and expensive process, time-pregnant dams were obtained as early as possible from a commercial supplier, on day 3 of gestation, and immediately switched to the experimental diet. At birth, the milk of dams prepared by these two different methods was compared by collecting the stomach contents of the pups. This showed a slight increase in docosahexaenoic acid (DHA) and arachidonic acid (AA) in the pup stomach contents from the time-pregnant dams. There were no significant changes in the brain fatty acid composition of pups between the two different lengths of the experimental diet intake. By the 10 days of age, there were only minor differences in the milk fatty acid composition of pup stomach contents from the two sets of dams. However, the pup brains of the time-pregnant groups at 10 days showed increased AA and DHA due to intake of the chow diet including AA, DHA and eicosapentaenoic acid (EPA). Thus, the history of the maternal feeding could affect the results under these particular circumstances, but the differences were minimal.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.492-500
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• 2017

The purpose of this study was to investigate the seasonal distribution of phytoplankton as prey for oysters and to characterize the environmental factors controlling their abundance from June 2016 to May 2017, in the northeast coast between Tongyeong and Saryang Island, particularly for the oyster farming area. During the survey period, water temperature changed from $7.54^{\circ}C$ in February to $29.5^{\circ}C$ in August. The abnormal high temperature persisted during one month in August. Salinity was low due to summer rainfall and typhoon. The lowest level was 30.68 psu in September, and it peaked at 34.24 psu in May. The dissolved oxygen (DO) concentration ranged from $6.0-9.45mg\;L^{-1}$, and the DO concentration in the surface layer was like that in the bottom layers. The seasonal trends of pH were also like those of DO. The pH ranged from 7.91 to 8.50. Nitrate with nitrite, phosphate, and silicate concentrations ranged from $0.14{\mu}M$ to $7.66{\mu}M$, from $0.01{\mu}M$ to $4.16{\mu}M$, and from $0.27{\mu}M$ to $20.33{\mu}M$, respectively. The concentration of chlorophyll a (Chl. a) ranged from $0.37{\mu}g\;L^{-1}$ to $2.44{\mu}g\;L^{-1}$ in the surface layer. The annual average concentration was $1.26{\mu}g\;L^{-1}$. The annual mean phytoplankton community comprised Bacillariophyta (69%), Dinophyta (17%), and Cryptophyta (10%), respectively. Dinoflagellate Prorocentrum donghaiense in June was the most dominant at 90%. In the summer, diatom Chaetoceros decipiens, Rhizosolenia setigera and Pseudo-nitzschia delicatissima were dominant. These species shifted to diatom Chaetoceros spp. and Crytophyta species in autumn. In the winter, high densities of Skeletonema spp. and Eucampia zodiacus were maintained. Therefore, the researchers thought that the annual mean Chl. a concentration was relatively lower to sustain oyster feeding, implying that the prey organism (i.e., phytoplankton) was greatly controlled by continuous filter feeding behavior of oyster in the vicinity area of the oyster culture farm.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.3
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• pp.271-279
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• 2018

Previous studies to elucidate the etiology of cyclosporine(Cs)-induced gingival overgrowth in children have not completely excluded all factors that may cause differences among individuals. This study examined the effect of cyclosporine on the metabolism of type 1 collagen(CoL-I) in experimental models that controlled the effects of biological variations on individuals. Five 5-week-old male Sprague-Dawley rats were administered Cs by gastric feeding for 6 weeks. Gingival specimens were harvested from the mandibular posterior area before beginning Cs administration and at 2, 4, and 6 weeks thereafter. Gingival fibroblasts were cultured from all the 20 biopsies collected from the gingiva. Half of the fibroblasts collected prior to the Cs administration were designated as Control. The other half of the fibroblasts were treated with Cs in vitro and called in vitro test group(Tt). The fibroblasts collected 2, 4, and 6 weeks after the Cs administration were called in vivo test groups : T2, T4, T6, respectively. Immunofluorescence microscopy was used to detect CoL-I in all the fibroblasts. CoL-I was analyzed at both the gene and protein expression levels by real-time polymerase chain reaction and western blotting. Changes in CoL-I before and after Cs treatment were evaluated from the gingiva of each rat. There was no significant difference in gene expression of CoL-I in the control and test groups. CoL-I protein expression levels of fibroblasts increased in in vitro Cs treatment for each individual, and also increased in in vivo Cs treatment. In this study, the experimental method that control biological variations that can occur due to differences among individuals was useful. Subsequent studies on other factors besides CoL-I and in-depth studies in humans are needed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.599-610
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• 2016

This paper reports the results of a systematic review (SR) and meta-analysis research to compare the effect of Kangaroo care, targeting mothers and premature infants. A randomized clinical trial study was performed until February 2015. The domestic literature contained the non-randomized clinical trial research without restriction according to the level of the study design. A search of the Ovid-Medline, CINAHL, PubMed and KoreaMed, the National Library of KOREA, the National Assembly Library, NDSL, KISS and RISS. Through the KMbase we searched and combined the main term ((kangaroo OR KC OR skin-to-skin) AND (care OR contact)) AND (infant OR preterm OR Low Birth Weight OR LBW), ((kangaroo OR kangaroo OR kangaroo) AND (care OR nursing care OR management OR skin contact)) was made; these were all combined with a keywords search through the selection process. They were excluded in the final 25 studies (n=3051). A methodology checklist for randomized controlled trials (RCTs) designed by SIGN (Scottish Intercollegiate Guidelines Network) was utilized to assess the risk of bias. The overall risk of bias was regarded as low. In 16 studies that were evaluated as a grade of "++", 9 studies were evaluated as a grade of "+". As a result of meta-analysis, kangaroo care regarding the effects of premature mortality, severe infection/sepsis had an insignificant effect. Hyperthermia incidence, growth and development (height and weight), mother-infant attachment, hypothermia incidence, length of hospital days, breast feeding rate, sleeping, anxiety, confidence, and gratification of mothering role were considered significant. In satisfaction of the role performance, depression and stress presented contradictory research results for individual studies showing overall significant difference. This study has some limitations due to the few RCTs comparing kangaroo care in the country. Therefore, further RCTs comparing kangaroo care should be conducted.

• Clinical and Experimental Pediatrics
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• v.52 no.11
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• pp.1216-1220
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• 2009

Purpose:To analyze and compare various cases in which peritoneal drainage was used as the primary treatment method in preterm infants with intestinal perforation. Methods:Among the preterm infants of less than 28 weeks of gestation who were admitted to the neonatal intensive care unit (NICU) at the Gangnam Severance Hospital from April 2006 to April 2009, 7 who had developed intestinal perforation were studied retrospectively. We investigated the clinical characteristics, secondary operation performances, morbidities, complications, and mortalities. Results:Among the 7 infants, 5 survived. Of the 5 cases, 3 received laparotomy, of which 2 were confirmed as having necrotizing enterocolitis. Of the 2 infants who died, 1 had received laparotomy before 48 h of peritoneal drainage, while the other had not received any subsequent treatment. Of the 7 children, 4 had patent ductus arteriosus (PDA), of which 3 had received indomethacin injection. Five infants had begun enteral feeding before they developed intestinal perforation. Of the 5 infants who survived, 4 were diagnosed with cholestasis. Of the 7 infants, 4 developed periventricular leukomalacia (PVL) and 3 developed rickets. Conclusion:Although the use of peritoneal drainage as the primary management of intestinal perforation in preterm infants is controversial, we suggest that it can be used for treating extreme premature neonates. Further randomized controlled study will be required to determine the feasibility of using this method.