• Journal of environmental and Sanitary engineering
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• v.17 no.2
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• pp.26-33
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• 2002

Ultimate objective of industrial hygiene is the prevention of health impairment that may result from exposure to chemicals at workplace. Workers in solvent thinner-using occupation environment may be highly exposed to VOCs (volatile organic compounds) because solvent thinner has been used extensively such as painting, spraying, degreasing, coating and so on in Korea. The purpose of this study was to recognize, evaluate, and propose the control methods of VOCs from solvent thinner-using workplace. Five target volatile organic compounds (benzene, toluene, ethylbenzene, o-xylene, and m-xylene) were monitored in H company of Shiwa Industrial Complex and analyzed in perosnal, occupational indoor and outdoor during working hours simultaneously. Engineering control such as local ventilation should be made in considering the long-term exposure, though measured VOCs concentration did not exceed the workplace exposure standards. In addition, air cleaning device should be installed in local ventilation because Shiwa Industrial Complex has had the serious ambient air pollution. Currently, environmental purification using $TiO_2$ photocatalyst have attracted a great deal of attention with increasing number of recent environmental problems. In this study, $TiO_2$ sol coated on the ceramic bead was prepared by sol-gel method and the photodegradation of target compounds was investigated in gas phase by the exposure to UV-A lamp(365nm) in a batch system.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.1
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• pp.73-77
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• 2005

Plant-derived natural products have been and will continue to be valuable sources. Elicitors have been employed to modify cell metabolism in order to enhance the productivity of useful metabolites in plant cell/tissue cultures. In this study, several elicitors were used to improve the productivity of useful metabolites and to reduce culture time for archiving high concentration in P. ginseng hairy root cultures. The addition of chitosan, chitosan oligosaccharide and alginate oligosaccharide to the culture of P. ginseng hairy roots caused growth to be inhibited with the increase in elicitor concentration. The usage of the chitosan elicitor and D-glucosamine caused a slight decrease in hairy root growth, whereas total ginseng saponin accumulated slightly with the increase in elicitor concentration. When gel beads were added to the culture medium at the initial period, hairy root growth was enhanced. The maximum growth was 1.35 times higher than that of the control at $1\%$ (w/v). Total ginseng saponin content decreased due to the addition of alginate beads. This would result in consistent diffusion of lower levels of calcium ions during the culture period that promotes biomass growth.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.3
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• pp.423-427
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• 2004

Seventy-six animals including cattle, sheep, horses, 6 species of zoo animals were employed for collection of fresh feces in order to detect verotoxigenic Esherichia coli (VTEC) by safe, quick and sensitive PCR-based molecular methods. Bacterial cell disruption with bead-beating followed by bacterial DNA purification with hydroxyapatide chromatography and gel filtration allowed DNA preparation from animal feces with high recovery and purity. A mountain goat was firstly shown by PCR and sequencing to shed verotoxin 2 gene (vt2) that was used to generate vt2 probe and second primer set for nested PCR to attempt more sensitive detection. Most sensitive nested PCR revealed that 45% of tested cattle and 47% of tested zoo animals were VTEC-positive, while least sensitive normal PCR detected VTEC from none of these animals except a mountain goat. Moderately sensitive detection by PCR in combination with hybridization suggested that the VTEC density varied between the VTEC-positive cattle.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.60-67
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• 2008

The catalytic filter of Cu-ZSM5/alumina beads was considered to reduce NOx in the urea SCR system. Catalytic support of porous alumina beads with mean pore size $130{\mu}m$ and porosity $75{\sim}83%$ were prepared using foaming and gel-casting method. The Cu-ZSM5 catalysts were coated on the supporting alumina beads using $Cu(NO_3)_2$ by ion exchange method. After a washcoating process was applied to coat 10w% Cu-ZSM5 on porous alumina bead, coating layer was estimated $20{\mu}m$ in thickness. The characterization and the feasibility as a catalytic supports were investigated. And the NOx conversion test in Cu-ZSM5/Alumina Beads filter system was conducted by using Urea as reductants under laboratory test. The NOx conversion was increased as size and porosity of beads and observed more than 95% excellent NOx conversion above $300^{\circ}C$.

• Journal of Pharmaceutical Investigation
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• v.29 no.4
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• pp.323-327
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• 1999

To protect ${\beta}-carotene$ at the stomach and to release rapidly at the intestine we prepared alginate beads containing ${\beta}-carotene$. ${\beta}-carotene$ and alginate solution was homogenized and prepared o/w emulsion was prepared. It was poured into $Ca^{2+}$ solution through syringe needle. The gel was formed spontaneously and alginate beads containing ${\beta}-carotene$ were prepared. ${\beta}-Carotene$ was incorporated into the beads more than 95%. The release rate of ${\beta}-carotene$ was dependent on the concentration of $Ca^{2+}$, ${\beta}-carotene$ and surfactants. However, the concentration of alginate did not affect the release rate of ${\beta}-carotene$. The high concentration of $Ca^{2+}$ slowed down the release rate of ${\beta}-carotene$. The addition of surfactants in the ${\beta}-carotene$beads increased the release rate of ${\beta}-carotene$ in the order of Tween 80 > Cremophor > Span 20. The contents of ${\beta}-carotene$ and diameter of ${\beta}-carotene$ beads did not change significantly at $50^{\circ}C$ for 20 days.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.6
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• pp.419-425
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• 2001

A dense pellicular solid matrix has been fabricated by coating 4% agarose gel on to dense zironia-silica(ZS) spheres by watr-in-oil emulsification . The agarose evenly laminated the ZS bead to a depth of 30㎛, and the resultin gpellicular assembly was characterised by densities up to 2.39g/mL and a mean particle dimeter of 136 ㎛. In comparative fluidisation tests, the pellicular solid phase exhibited a two-fold greater flow velocity than commercial benchmark ad-sorbents necessary to achieve common values of bed expansion. Furthermore, the perlicular parti-cles were characterised by improved qualities of chromatographic behaviour, particularly with re-spect to a three-fold increase in the apparent effective diffusivity of lysozyme within a pellicular assembly modified with Cibacron Blue 3GA. The properties of rapid protein adsorption/desorp-tion were attributed to the physical design and pellicular deployment of the reactive surface in the solid phase. When combined with enhanced feedstock throughput, such practical advantages recommend the pellicular assembly as a base matrix for the selective recovery of protein products from complex, particulate feedstocks(whole fermentation broths, cell disruptates and biological extracts).

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.5
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• pp.287-293
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• 2005

In this work, to develop soil inoculant which maintains stable viable cells and normalized quality, studies on micro-encapsulation with bacteria and yeast cells were performed by investigating materials and methods for micro-encapsulation as well as variation and stability of encapsulated cells. Preparation of capsule was conducted by application of extrusion system using micro-nozzle and peristaltic pump. K-carragenan and Na-alginate were selected as best carrier for gelation among K-carageenan, Na-alginate, locust bean gum, cellulose acetate phthalate (CAP), chitosan and gelatin tested. Comparing the gels prepared with Bacillus sp. KSIA-9 and carriers of 1.5% concentration, although viable cell of K-carragenan and Na-alginate was six times higher than those of other, Na-alginate was finally selected as carrier for gelation because it is seven times cheaper than K-carragenan. The gel of 1.5% Na-alginate was also observed to have the best morphology with circular hardness polymatrix and highest viable cell. When investigating the stability of encapsulated cells and the stabilizer effect, free cells were almost dead within 30 or 40 days whereas encapsulated cells decreased in 10% after 30 days and 15-30% even after 120 days. As stabilizer for maintaining viable cell, both 1% starch and zeolite appeared to possess the level of 70-80% cell for bacteria and yeast until after 120 days.

• KSBB Journal
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• v.18 no.2
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• pp.161-164
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• 2003

Oral drug delivery system using pectin gel was developed for colon-targeting of peptide drug. BSA(bovine serum albumin)-loaded pectin and pectin-alginate beads were prepared for drug release properties in vitro. Morphological studies by electron microscopy indicated that pectin and pectin-alginate beads were spherical in shape and approximately 1.0 mm. In order to find the suitable beads, effects of cross-linking agents (calcium chloride or zinc acetate) and drying temperature of beads were investigated. Drug release decreased with concentration of cross-linking agents and drying temperature. For colonic drug delivery from pectin and pectin-alginate beads, pectin degradable enzymes were added at 5 hrs from the beginning of drug release. After addition of enzymes, drug release was suddenly increased against free enzymes. Therefore, pectin and pectin-alginate beads can be promised as useful drug release carriers for colon-targeted delivery.

• KSBB Journal
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• v.23 no.1
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• pp.59-64
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• 2008

Optimum conditions for production of casein phosphopeptides (CPP) from sodium casenate by immobilized cell culture of Streptococcus faecalis var. liquefaciens were investigated. Immobilized cells were made by mixing 60% sodium alginate solution with an equal volume of culture broth at the end of exponential phase and subsequently dropping the mixture into $CaCl_{2}$ solution. Optimum conditions for CPP production by the immobilized cells were the same as those ($50^{\circ}C$, pH 7.0, and 10% substrate concentration) by the crude enzyme solution from the supernatant of culture broth. Optimum loading volume of the immobilized cells into a batch reactor was 30% (w/v). Using a continuous reactor loaded by the immobilized cells under the identified optimal conditions, we were able to produce CPP continuously up to 30 days with a maximum CPP conversion efficiency of 20%.

• Journal of Life Science
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• v.9 no.5
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• pp.556-563
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• 1999

Presence of antibody to the capsid protein p24 is the main diagnostic criterion, since this reflects reliable antibody response to HIV infection. However, it takes about 6-8 weeks for antibody production after infection and people who are infected but antibodies are not produced yet are classified as seronegative. Therefore, there is a strong need for an improved diagnostic method for better health security. As a first step for developing such an improved diagnostic system, gag protein of human immunodificiency virus type 1 was expressed in E. coli DH5$\alpha$. The gag fragment of HIV-1 (including a portion of p17 and whole p24) was amplified by polymerase chain reaction (PCR) and BamH I/EcoR I sites were created during PCR. The amplified DNA fragment was cleaved with BamH I/EcoR I and was subcloned into the GEX-2T vector which had been digested with BamHI/EcoRI, resulting gene fusion with gst gene of pGEX-2T. The recombinant DNA was transferred into E. coli DH5$\alpha$. The transformed bacteria were grown at 37$^{\circ}C$ for 3h and protein expression was induced with 0.1mM IPTG at $25^{\circ}C$ for 3h. Recombinant gag protein or GST-gag fusion protein was purified with glutathione-sepharose 4B bead and migrated as a single band when analyzed by 10% polyacrylamide gel. These proteins were confirmed by immunoblotting with anti-GST goat sera or Korean AIDS patients sera. The results of this study establish the expression and single step pulification of HIV-1 gag protein which can specifically bind with Korean AIDS patients sera.