• Biomaterials Research
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• v.22 no.4
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• pp.249-258
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• 2018

Background: Mucoadhesive polymers, which may increase the contact time between the polymer and the tissue, have been widely investigated for pharmaceutical formulations. In this study, we developed a new polysaccharide-based mucoadhesive polymer with thermogelling properties. Methods: Hexanoyl glycol chitosan (HGC), a new thermogelling polymer, was synthesized by the chemical modification of glycol chitosan using hexanoic anhydride. The HGC was further modified to include thiol groups to improve the mucoadhesive property of thermogelling HGC. The degree of thiolation of the thiolated HGCs (SH-HGCs) was controlled in the range of 5-10% by adjusting the feed molar ratio. The structure of the chemically modified polymers was characterized by $^1H$ NMR and ATR-FTIR. The sol-gel transition, mucoadhesiveness, and biocompatibility of the polymers were determined by a tube inverting method, rheological measurements, and in vitro cytotoxicity tests, respectively. Results: The aqueous solution (4 wt%) of HGC with approximately 33% substitution showed a sol-gel transition temperature of approximately $41^{\circ}C$. SH-HGCs demonstrated lower sol-gel transition temperatures ($34{\pm}1$ and $31{\pm}1^{\circ}C$) compared to that of HGC due to the introduction of thiol groups. Rheological studies of aqueous mixture solutions of SH-HGCs and mucin showed that SH-HGCs had stronger mucoadhesiveness than HGC due to the interaction between the thiol groups of SH-HGCs and mucin. Additionally, we confirmed that the thermogelling properties might improve the mucoadhesive force of polymers. Several in vitro cytotoxicity tests showed that SH-HGCs showed little toxicity at concentrations of 0.1-1.0 wt%, indicating good biocompatibility of the polymers. Conclusions: The resultant thiolated hexanoyl glycol chitosans may play a crucial role in mucoadhesive applications in biomedical areas.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.4
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• pp.559-568
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• 2012

White (Lohmann LSL) and Brown (ATAK-S) laying hens, were reared under organic and conventional cage rearing systems, and the effects of the rearing system on performance parameters, egg production, egg characteristics, and immune response were investigated. For this purpose, a total of 832 laying hens of two commercial hybrids, i.e., 416 white (Lohmann LSL) and 416 Brown (ATAK-S) layers, were used. The experiment lasted between 23 and 70 wk of age. In this study, the white layers yielded more eggs as compared to the brown layers in both organic and conventional production systems. Egg weight exhibited a similar pattern to that of laying performance. However, the total hen-housed egg number for the white birds in the organic system was fewer than that of white birds in the conventional cage facility; conversely, a contradictory tendency was observed for the brown birds. Livability of the white layers in the organic system was remarkably lower (14%) than that of the brown line, whereas the white line survived better (3.42%) than their brown counterparts in conventional cages. The feed conversion ratio of the white hens was markedly inferior in the organic system as compared to that of the white hens in the conventional system, whereas relatively lower deterioration was reported in brown layers when reared in an organic system. The organic production system increased egg albumen height and the Haugh unit in eggs of the brown layers. The yolk color score of organic eggs was lower than that of conventional eggs for both brown and white hens. The egg yolk ratio of eggs from white layers was found to be higher in organic eggs as compared to those obtained in the conventional system. All organic eggs had heavier shells than those produced in the conventional system. Eggs from brown layers had more protein content than eggs from white layers. Neither housing systems nor genotype influenced egg yolk cholesterol concentration. When compared to conventional eggs, n-3 fatty acid content was lower in organic eggs, and the n-6:n-3 ratio was higher in organic eggs. In conclusion, two hen genotypes showed different responses in terms of performance and egg quality to two different rearing systems. A commercial white strain produced more eggs with higher egg quality as compared to a native brown strain. The brown strain was found to have adapted well to organic production conditions when survival and total egg number was taken into consideration.

• Journal of environmental and Sanitary engineering
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• v.16 no.2
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• pp.79-90
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• 2001

Commercial liquid seeds are used for supplying active microbial flora to organic wastewater treatment plants of high feed-to-microorganism ratio and to maintain optimal microbial condition during unsteady state operation of the biological wastewater treatment plant. In addition to bacterial cells, the liquid weeds contain various additives for special purposes as well as organic substrates for energy supply. The additives give physical stability for the maintenance of microbial decomposition activity and ability to control the overgrowth of seed strains. In this work, the effects of addition of two kinds of typical substrate additives, poly aluminum chloride(PAC) and poly aluminum sulfate(PAS) on the consitutional total cell counts(CFU/ml) of four kinds of reorganization liquid seeds(RLS I, RLS II, RLS III and RLS IV) were studied experimentally. The addition of PAC and PAS gave negative effect on TCC constitution for the four seeds studied.

• Korean Chemical Engineering Research
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• v.43 no.2
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• pp.266-271
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• 2005

This paper studied succinic acid recovery from organic acid mixture by using mono-polar membrane electrodialysis. Current efficiency, solute recovery efficiency, energy consumption, and separation factor were measured at various pHs and concentration ratios. The separation factor of succinic acid could be interpreted in terms of ionization degree, molecular weight, ionic conductance, average charge, and initial feed composition.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.179-182
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• 2004

This study reports the extraction behavior of $\alpha$-lactalbumin using bis(2-ethylhexyl) sulfosuccinate sodium (AOT) reverse micelles. Forward extraction of $\alpha$-lactalbumin in the reverse micellar organic phase from aqueous feed solutions was strongly dependent on the AOT concentration and the complete forward extraction of 0.03 mM $\alpha$-lactalbumin was successfully achieved at an AOT concentration of ca. 100 mM. A similar dependency of the forward extraction on the AOT concentration was obtained in isooctane, n-hexane, and n-octane systems. In the backward extraction from the micellar organic phase, the recovery of the protein as high as ca. 90% was obtained with pH control and/or salt addition.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.10
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• pp.1513-1520
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• 2014

The present aim was to investigate the effects of traditional Chinese medicine prescriptions (TCM) on body temperature, blood physiological parameters, nutrient apparent digestibility and growth performance of beef cattle under heat stress conditions. Twenty-seven beef cattle were randomly divided into three groups as following; i) high temperature control (HTC), ii) traditional Chinese medicine prescriptions I+high temperature (TCM I) and iii) traditional Chinese medicine prescriptions II+high temperature (TCM II) (n = 9 per group). The results showed that the mean body temperature declined in TCM II treatment (p<0.05). Serum $T_3$ and $T_4$ levels with TCM I and TCM II treatments elevated (p<0.05), and serum cortisol levels of TCM I treatments decreased (p<0.05), compared with the HTC group. Total protein, albumin, globulin in TCM II treatments elevated and blood urea nitrogen levels of both TCM treatments increased, but glucose levels of both TCM treatments decreased, compared with the HTC group (p<0.05). The apparent digestibility of organic matter and crude protein with TCM I treatment increased, and the apparent digestibility of acid detergent fiber elevated in both TCM treatments (p<0.05). Average daily feed intake was not different among three groups, however average daily gain increased and the feed:gain ratio decreased with both TCM treatments, compared with the HTC group (p<0.05). The present results suggest that dietary supplementation with TCM I or TCM II improves growth performance of heat stressed beef cattle by relieving heat stress responses and increasing nutrient apparent digestibility.

• Korean Journal of Organic Agriculture
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• v.13 no.3
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• pp.315-332
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• 2005

This study was conducted to assess the nutritional value and the safety of the fermented food wastes (FFW) made by adding lactobacillus spp. and bacillus spp. at the ratio of 3:7, respectively to food wastes collected everywhere, and also to determine effects on the performances, carcass characteristics and economical profitability when FFW was fed to pigs. For swine trial, FFW was formulate to pellet by utilizing different feed ingredients, and its formulated FFW pellet was used in this feeding trial. Treatments were consisted of different ratios (T1: $100+0\%$, T2: $75+25\%$, T3: $50+50\%$, T4: $25+75\%$, T5: $0+100\%$) of FFW pellet to commercial diet. A total of 20 male pigs were allotted to treatments of five groups of four pigs per pen. Experimental period lasted for 4 months. The nutritional composition of FFW was 56.7, 19.5 and $19.5\%$ for moisture, crude protein and ether extract, respectively. Salt content was $0.39\%$. Noxious microorganisms such as salmonella and E. coli were not detected in FFW, and contents of heavy metal and aflatoxin B1 were lower than the standard. Nutritional values of FFW pellet satisfied over $100\%$ of requirements presented in official Korean feeding standard for swine. Feeding trial for pigs showed that feed intakes were significantly (P<0.05) decreased with increasing levels of FFW pellet. T2 treatment was ideal ratio under the consideration of economical value of feeds and body weight gain of pigs. For carcass characteristics, dressing rate ($\%$) was highest in T3, and carcass grades for T2, T3 and T4 treatments were estimated as 'A'. Feed cost for FFW per kg was ${\won}167.95$, which implies $52\%$ of commercial feed cost (${\won}350/kg$). Thus, this result implied the decreased feed cost in the swine farm. Conclusively, the utilization of food wastes as feed source may lead to the reduced environmental pollution and the practice of organic livestock farming. However, our results showed that excessive amount of fermented food wastes supplementation to pigs might give rise to their reduced palatability and delayed growth.

• Korean Journal of Poultry Science
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• v.36 no.2
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• pp.139-147
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• 2009

This experiment was conducted to investigate the effect of organic dietary ME and CP on performance, blood composition and meat quality of cross-bred chicks for 15 weeks. Experiments were factorially designed with 3,000, 3,050, and 3,100 kcal of ME/kg, and 21 and 22% CP for the first five weeks; 3,050, 3,100, and 3,150 kcal of ME/kg, and 19 and 20% CP for the second five weeks; and 3,100 and 3,150 kcal of ME/kg, and 17 and 18% CP for the rest of weeks. Each treatment consisted of four replicates. Weight gain increased in treatments with higher ME diets for the first five weeks, but feed intake decreased significantly as dietary ME increased (P<0.05). Feed conversion also improved in chicks fed 3,100 kcal of ME/kg diets compared with those of 3,000, and 3,050 kcal of ME/kg (P<0.05), but was not influenced by dietary protein. Weight gain and feed conversion showed similar tendency for the second five weeks to those of the first five weeks. However, feed conversion improved significantly in 3,100 and 3,150 kcal of ME /kg compared to 3,050 kcal of ME/kg (P<0.05). Dietary protein did not affect the performance at all for this period. Weight gain and feed intake tended to increase in higher ME and lower protein diets from 11 to 15 weeks of age, whereas feed conversion decreased in 3,150 kcal of ME/kg more than 3,000 kcal/kg. No difference was found by CP treatments (P<0.05). There were no interactions in performance, blood composition and meat quality between dietary ME and protein. Further studies need to describe in whole period experiments instead of periodical experiment.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.04a
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• pp.29-32
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• 1994

The increasing environmental risks exert strong demands for the knowledge of environmentally significant compounds and the reduction of such compounds on the earth. The risk reduction can, in principle, be most effectively achieved by minimizing the formation of environmental pollutants, by-products in many cases, during processes in factories, power plants and other sources. This can be done by on-line, real time monitoring the formation of pollutants at the moment when they are formed, and thereby through the feed-back control of the process.

• Proceedings of the Membrane Society of Korea Conference
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• 1991.10a
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• pp.1-3
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• 1991

A novel membrane separation process for the separation of liquid mixture is Pervaporation. The term, 'pervaporation', is a combination of permeation and evaporation, and was first introduced by kober[1] in 1917. In this technique, the liquid mixture in feed is in contact with one side of a dense non-porous membrane and after diffusing through the membrane is removed from the downstream side in the vapor phase, but is usually condensed afterwards to obtain a permeate in liquid from.