• Bulletin of the Korean Chemical Society
• /
• v.34 no.1
• /
• pp.154-158
• /
• 2013

Development of dual functional liposome has been studied for cancer theragnostics. Therefore, we focused on ultrasound-sensitive liposomes with doxorubicin (DOX) and gadolinium (Gd) as a theragnostic carrier having a potential for cancer therapy and diagnosis. In this study, Gd(III)-DOTA-modified sonosensitive liposomes (GL) was developed using chemically synthesized Gd(III)-DOTA-DPPE lipid. Sonosensitivity of GL to 1 MHz ultrasound induced 25% of DOX release. The relaxivities ($r_1$) of GL were $7.33-10.34\;mM^{-1}s^{-1}$, which was higher than that of MR-bester$^{(R)}$. Intracellular delivery of DOX from GL by ultrasound irradiation was evaluated according to ultrasound intensity, resulting in increase of uptake of DOX released from ultrasound-triggered GLs compared to GL3 or Doxil$^{(R)}$ without ultrasound. Taken together, this study shows that the paramagnetic and sonosensitive liposomes, GL, is a novel and highly effective delivery system for drug with the potential for broad applications in human disease.

• Korean Journal of Environmental Agriculture
• /
• v.26 no.3
• /
• pp.228-232
• /
• 2007

Slow-release fertilizers (SRF) have been used to reduce nutrient loss through increasing fertilizer efficiency and to save labor. Several SRFs were developed for rice plant in Korea, but there is few for horticultural crop plants. Two slow-release complex fertilizers, 100T and 150T, which made for controlling nitrogen release time up to 100 and 150 days, respectively, were selected for the incubation test cto evaluate nitrogen (N) release rate in soil. The N of urea selected as the control was completely released within a week after application. Sixty three and 53% of total N were released from 110T and 150T of slow release fertilizers within 8th weeks after application, respectively. For pepper cultivation CF110 and CF150, new slow-release complex fertilizer, were made of mixing 40% of conventional fertilizer and 60% of 110T and 150T, respectively, based on the amount of recommended fertilizer for pepper cultivation $(N-P_2O_5-K_2O=190-112-149\;kg\;ha^{-1})$, and were totally applied before pepper transplanting in the field as the basal fertilizer. Inorganic N $(NH_4^+-N+NO_3^--N)$ concentration in soil was higher in the CF110 treatment than in the control (NPK) at all period of pepper cultivation. In the CF150 treatment concentration of inorganic N in soil was low compared to control up to 8th weeks after transplanting. However, there was no difference in plant height and nutrient content of pepper leave between CF110 treatment and the control. In comparison, plant height was significantly lower in CF150 than the control and CF110 treatments. Around 4% of fresh pepper yield was increased in CF110 compared to the control, but it was decreased to about 2% by CF150 treatment. Conclusively, CF110 form could be recommended as a slow release fertilizer for pepper cultivation.

• 한국생물공학회:학술대회논문집
• /
• 2003.04a
• /
• pp.739-742
• /
• 2003

Curdlan acetate was prepared from hydrophilic curdlan by chemical modification and it was used for pH-sensitive drug delivery system. Curdlan acetate microspheres were prepared by the solvent evaporation method. The size of the curdlan acetate microspheres was below $200\;{\mu}m$. The drug loading efficiency of microspheres was approximately 58.44%. In the swelling test, curdlan acetate microspheres were showed pH-sensitive behavior. The swelling capacity of microspheres at pH 7.4 was much greater than at pH 1.4. Also, Release rate of indomethacin (IND) at pH 7.4 from curdlan acetate microspheres was faster than that at pH 1.4. A pH-sensitive drug release pattern was due to the disintegrating after swelling.

• Journal of the Korean Society of Safety
• /
• v.9 no.1
• /
• pp.89-94
• /
• 1994

Two methods, the numerical method of CPQRA and the manual method of IAEA, were used to estimate the effect distance from release and dispersion of toxic materials. The Gaussian plume model which has a weather stability class D with wind velocity of 5m/s was applied to calculate dispersion of toxic materials. Also, probit function were employed to evaluate the human fatality as a result of exposure to toxic gases. Furthermore, concentration of toxic materials corresponding to LC$_{50}$ for 30 min could be determined by setting Pr as 5.0 and solving the probit function. Calculations were conducted by employing chlorine and ammonia as toxic materials because they are not only most commonly used In chemical plants but also very harmful to humans. Calculated results by employing toxic materials indicated that the effect distance from the CPQRA method was between the minimum and maximum distance from the method proposed by IAEA.A.

• Nuclear Engineering and Technology
• /
• v.52 no.8
• /
• pp.1638-1649
• /
• 2020

In the case of a severe accident in a Light Water Reactor, the issue of late release of fission products, from the primary circuit surfaces is of particular concern due to the direct impact on the source term. CsI is the main iodine compound present in the primary circuit and can be deposited as particles or condensed species. Its chemistry can be affected by the presence of molybdenum, and can lead to the formation of gaseous iodine. The present work studied chemical reactions on the surfaces involving gaseous iodine release. CsI and MoO₃ were used to highlight the effects of carrier gas composition and oxygen partial pressure on the reactions. The results revealed a noticeable effect of the presence of molybdenum on the formation of gaseous iodine, mainly identified as molecular iodine. In addition, the oxygen partial pressure prevailing in the studied conditions was an influential parameter in the reaction.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.20 no.2
• /
• pp.605-615
• /
• 1996

Laminar flows in which mixing and chemical reactions take place between parallel streams of reactive species are studied numerically. The governing equations for laminar flows are from two-dimensional compressible boundary-layer equations. The chemistry is a finite rate single step irreversible reaction with Arrhenius kinetics. Ignition, premixed flame, and diffusion flame regimes are found to exist in the laminar reacting mixing layer at high activation energy. At high Mach numbers, ignition occurs earlier due to the higher temperatures in the unburnt gas. In diffusion regimes, property variations affect the laminar profiles considerably and need to be included when there are large temperature differences. The maximum temperature of a laminar reacting mixing layer is almost linear with the adiabatic flame temperature at low heat release, but only weakly at high heat release.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.7 no.6
• /
• pp.335-339
• /
• 2002

Laboratory experiments were conducted using pure cultures of Acinetobacter under an-aerobic/aerobic cyclic conditions to explain the release and uptake of soluble phosphate in an activated sludge process showing enhanced biological phosphate removal (EBPR). Under anaerobic/aerobic cyclic conditions in a Sequencing Batch Reactor (SBR), COD uptake concurrent with soluble phosphate release by Acinetobacter was not significant during the anaerobic periods, indicating that EBPR would not be established in pure cultures. However Acinetobacter cells accumulated higher phosphate content (5.2%) in SBR than that obtained (4.3%) from batch experiments. These results suggest that Acinetobacter sp. may not follow the proposed pattern of behavior of poly-P bacteria in EBPR activated sludge Plants.

• Archives of Pharmacal Research
• /
• v.27 no.1
• /
• pp.1-12
• /
• 2004

Initial burst is one of the major challenges in protein-encapsulated microparticle systems. Since protein release during the initial stage depends mostly on the diffusional escape of the protein, major approaches to prevent the initial burst have focused on efficient encapsulation of the protein within the microparticles. For this reason, control of encapsulation efficiency and the extent of initial burst are based on common formulation parameters. The present article provides a literature review of the formulation parameters that are known to influence the two properties in the emulsion-solvent evaporation/extraction method. Physical and chemical properties of encapsulating polymers, solvent systems, polymer-drug interactions, and properties of the continuous phase are some of the influential variables. Most parameters affect encapsulation efficiency and initial burst by modifying solidification rate of the dispersed phase. In order to prevent many unfavorable events such as pore formation, drug loss, and drug migration that occur while the dispersed phase is in the semi-solid state, it is important to understand and optimize these variables.

• Journal of Veterinary Clinics
• /
• v.8 no.2
• /
• pp.157-170
• /
• 1991

Effects of recombinant bovine somatotropln(${\gamma}$BST) on hematologie and blood chemical values were investigated in twenty-five multiparous Holstein dairy cows. Recombinant BST was administered by two different routes ; intramusculary(12.5mg and 25mg/day) and subcutaneously(500mg and 750mg) in sustained-release vehicle every 2 weeks beginning 4 weeks postpartum and continuing for 7 months. Whole blood and serum samples were collected 0, 1, 2, 3, 5, and 7 months after beginning of treatments from control and ${\gamma}$BST-administered groups. Hematologic values including RBC, PCV, HB, MCH, MCHC, WBC and differential counts of treatment groups receiving ${\gamma}$BST were similiar to those of control group. Blood chemical values observed were total protein, albumin, A/G ratio, glucose, cholesterol, Ca, Pi, Ca/pi ratio, total bilirubin, creatinine, BUN, alkaline phosphatase, lactate dehydrogenase, alanine aminotransferase and aspartate aminotransferase. There were no significant differences in blood chemical values of cows administered with ${\gamma}$BST from those of control. Although some blood chemical values were fluctuated at a certain observation period, they were remained within the normal physiological ranges. It is concluded from the observations of these experiments that the dose and dosage froms of ${\gamma}$BST employed in this work might not affect hematologic and blood chemical values in dairy cows under the normal sanitary condition and adequate nutritional balance.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.4
• /
• pp.1159-1164
• /
• 2014

A simple, highly sensitive and selective method based on the rhodamine B-covered gold nanoparticle with dual-readout (colorimetric and fluorometric) detection for $\small{L}$-cysteine is proposed. A mechanism is that citrate-stabilized AuNPs were modified with RB by electrostatic interaction, which enables the nanometal surface energy transfer (NSET) from the RB to the AuNPs, quenching the fluorescence. In the presence of $\small{L}$-cysteine, it was used as a competitor in the NSET by the strongly Au-S bonding to release RB from the Au surface and recover the fluorescence, and the red-to-purple color change quickly, which was monitored simply by the naked eye. Under the optimum conditions, the detection limit is as low as 10 nM. The method possessed the advantages of simplicity, rapidity and sensitivity at the same time. The method was also successfully applied to the determination of $\small{L}$-cysteine in human urine samples, and the results were satisfying.