• Biomolecules & Therapeutics
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• v.19 no.3
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• pp.357-363
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• 2011

In relieving local pains, ropivacaine has been widely used. In case of their application such as ointments and creams, it is difficult to expect their effects for a significant period of time, because they are easily removed by wetting, movement and contacting. Therefore, the new formulations that have suitable bioadhesion were needed to enhance local anesthetic effects. The effect of drug concentration and temperature on drug release was studied from the prepared 1.5% Carboxymethyl cellulose (CMC) (150MC) gels using synthetic cellulose membrane at $37{\pm}0.5^{\circ}C$. As the drug concentration and temperature increased, the drug release increased. A linear relationship was observed between the logarithm of the permeability coefficient and the reciprocal temperature. The activation energy of drug permeation was 3.16 kcal/mol for a 1.5% loading dose. To increase the skin permeation of ropivacaine from CMC gel, enhancers such as saturated and unsaturated fatty acids, pyrrolidones, propylene glycol derivatives, glycerides, and non-ionic surfactants were incorporated into the ropivacaine-CMC gels. Among the enhancers used, polyoxyethylene 2-oleyl ether showed the highest enhancing effects. For the efficacy study, the anesthetic action of the formulated ropivacaine gel containing an enhancer and vasoconstrictor was evaluated with the tail-flick analgesimeter. According to the rat tail-flick test, 1.5% drug gels containing polyoxyethylene 2-oleyl ether and tetrahydrozoline showed the best prolonged local analgesic effects. In conclusion, the enhanced local anesthetic gels containing penetration enhancer and vasoconstrictor could be developed using the bioadhesive polymer.

• Journal of Pharmaceutical Investigation
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• v.26 no.4
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• pp.245-256
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• 1996

Solid lipid nanoparticles (SLN) have been developed as a new drug delivery system. Although many particulate drug carriers, such as microsphere, liposome, niosome, emulsion, etc. have been introduced, they have some disadvantage; low efficiency of incorporation and stability, lack of reproducibility, and so on. Meanwhile, SLN as a new drug delivery system is known to entrap rugs with a high efficiency and a good reproducibility. Moreover, small size SLN can circulate in blood for a prolonged time. Although many preparation methods were introduced, microfluidization method is recommended to be the most useful. This study was attempted to prepare and evaluate ketoprofen-incorporated SLNs (keto-SLN), which were prepared by two methods, ultrasonication and microfluidization. Keto-SLN was evaluated by measurement of particle size and zeta potential, efficacy of entrapment, sedimentation volume, in virto release pattern. The mean particle size was about $0.1\;{\mu}m$, and the size was dependent on the type and the amount of emulsifier. Zeta potential was negative, $-9{\sim}-13mV$ and entrapment efficacy was very high and stability was good for at least 60 days in the respect of particle size and sedimentation volume ratio. Analgesic effect was also determined as well as pharmacokinetic parameters. The former was comparable to that of that of ketoprofen loaded suspension (keto-sus) and the latter revealed that consistent with the delayed release of keto-SLN. $T_{max}$ was longer than keto-sus. Therefore, keto-SLN was favourable dosage forms in the field of drug delivery system such as anti-cancer, analgesics and anti-inflammatory agents.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.2
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• pp.229-232
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• 1997

Effects of short-term treatment with somidobove (recombinantly produced bovine somatotropin, BST) on estrous cyclicity and fertility were studied in dairy buffaloes. Twenty buffaloes of Nili-Ravi breed calving during the same season were assigned to either control (n=8) or treated group (n=12). The buffaloes of treated group received single infection (prolonged release) of 320 mg of somidobove on day-60 postpartum. The mean values for interval to first postpartum estrus, first service conception rate, services per conception, service period and calving interval for the treated group were 96.4 days, 66.7%, 1.70, 164 days and 473 days, respectively. The corresponding values for the control group were 92.5 days, 62.5%, 1.87, 135 days and 439 days. Means of all variables did not differ between control and treated group (p > 0.05). Three buffaloes of the control and four buffaloes of the treated group did not conceive at first service. Out of these, two buffaloes of control and one buffalo of treated group exhibited normal estrous cycles. It is concluded from these data that short term BST-treatment has no adverse effect on reproductive functions of dairy buffaloes.

• Nuclear Engineering and Technology
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• v.49 no.7
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• pp.1431-1441
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• 2017

The Fukushima accident reveals the vulnerability of existing active nuclear power plant (NPP) design against prolonged loss of external electricity events. The passive safety system is considered an attractive alternative to cope with this kind of disaster. Also, the passive safety system enhances both the safety and the economics of NPPs. The adoption of a passive safety system reduces the number of active components and can minimize the construction cost of NPPs. In this paper, reflecting on the experience during the development of the APR+ design in Korea, we propose the concept of an innovative Power Reactor (iPower), which is a kind of passive NPP, to enhance safety in a revolutionary manner. The ultimate goal of iPower is to confirm the feasibility of practically eliminating radioactive material release to the environment in all accident conditions. The representative safety grade passive system includes a passive emergency core cooling system, a passive containment cooling system, and a passive auxiliary feedwater system. Preliminary analysis results show that these concepts are feasible with respect to preventing and/or mitigating the consequences of design base accidents and severe accidents.

• YAKHAK HOEJI
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• v.42 no.3
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• pp.274-274
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• 1998

Aclarubicin(ACL)-entrapped freeze dried liposomes were prepared using Microfludizer to attain a sustained release at targeted organs in a prolonged time so that it can reduce th e side effect and maximize the therapeutic effect. The freeze-dried liposomes were evaluated for pharmacokinetics, antitumor activity against Sarcoma 180, cytotoxicity against L1210 and A549 tumor cells, spleen toxicity and myelosuppressive action. The AUC0->8hr values were 122+/-42, 382+/-140, 419+/-171, 835+/-206 and 443+/-309mcg min/ml for free ACL. ACL-liposome formulation I, II, III and IV, respectively. Cytotoidcity of ACL-entrapped liposomes against L1210 and A549 tumor cells was 2-4 times higher than that of free aclarubicin. ACL-liposome formulation I(PC/CHOL/TA) showed the most potent antitumor activity against Sarcoma 180 in mice. The loss of body weight was much smaller with ACL-entrapped liposomes than free ACL after I.p. injection at a dose of 2 mg/kg/day. Compared to free ACL, ACL-entrapped liposomes expressed a lower and delayed spleen toxicity up to 5th day after I.v. administration. Myelosupperssion seemed to be lower with ACL-entrapped liposome of PC/PC-hydrate/CHOL/TA (formulation III) than free aclarubicin.

• YAKHAK HOEJI
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• v.39 no.4
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• pp.373-379
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• 1995

Coupling of tetracycline (Tc) to dithiocarbamate chitosan(DTCC) via chelate bond was carried out in the presence of Mg (II) ion by one- and two-bath process. In one-bath process, DTCC was treated with Mg(II)-Tc solution. In two-bath process, DTCC was treated with Mg(II) to produce DTCCMg(II), which was isolated and treated in turn with Tc solution. The effect of pH and temperature on binding of Tc, was investigated varying the pH of the solution from 2.6 to 3.2 at 10 and $30^{\circ}C$. Binding of Tc was not affected greatly by such variations in pH and temperature. Amount of Tc bound to 1 gm of matrix reached to 180 mg. Release of Tc from DTCC-Mg(II)-Tc was investigated by batch and flow method, and the amount of Tc released against time followed by flow method exhibited near linear relationship. DTCC-Mg(II)-Tc showed very prolonged antimicrobial activity compared to that of free Tc when it was tested against Escherichia coli TG-1 and Bacillus subtilis NA-1.

• Korean Journal of Materials Research
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• v.24 no.12
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• pp.704-709
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• 2014

In this study, we fabricated a novel micro porous hybrid scaffold of biphasic calcium phosphate (BCP) and a polylectrolyte complex (PEC) of chitosan (CS) and hyaluronic acid (HA). The fabrication process included loading of CS-HA PEC in a bare BCP scaffold followed by lypophilization. SEM observation and porosimetry revealed that the scaffold was full of micro and macro pores with total porosity of more than 60 % and pore size in the range of $20{\sim}200{\mu}m$. The composite scaffold was mechanically stronger than the bare BCP scaffold and was significantly stronger than the CS-HA PEC polymer scaffold. Bone morphogenetic growth factor (BMP-2) was immobilized in CS-HA PEC in order to integrate the osteoinductive potentiality required for osteogenesis. The BCP frame, prepared by sponge replica, worked as a physical barrier that prolonged the BMP-2 release significantly. The preliminary biocompatibility data show improved biological performance of the BMP-2 immobilized hybrid scaffold in the presence of rabbit bone marrow stem cells (rBMSC).

• Journal of Aquaculture
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• v.20 no.3
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• pp.194-198
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• 2007

Reproductive traits of Palaemon gravieri such as embryo size, number of embryo (fecundity), incubation period, larval development mode, larval development period, larval survival and larval growth were described and compared to analyze the correlation among those traits. Embryo volume is a primary factor determining other ensuing reproductive features. Egg volume was $0.042mm^3$ in the first developmental stage. Embryo volume in P. gravieri was comparatively small which is indicative of great number of embryo (y = 3.0161x + 0.0185 $R^2$ = 0.74 positive isometric relationship) and relatively long incubation period. Larvae survived from zoea 1 to post-larvae and it took 45 days at $22^{\circ}C$. Survival rate of the larvae was rather great in the early stage and thereafter steadily decreased. Daily growth rate of larvae in P. gravieri at $22^{\circ}C$ was 0.0195 mm on average. They grew steadily as time went by. Incubation period was between 10-14 days at $22^{\circ}C$. Larval development mode was almost complete planktotrophic. PNR (point of no return) appeared to be the third day on average. Survival rate of larvae without feeding declined rapidly between 3 and 4 days. Larval development period and stage frequency were 23-30 days and 11 stages which imply prolonged larval period and high mortality. The pattern of brood production followed fast successive parturial pattern. Most ovigerous female had mature ovary when they performed parturial molt soon after hatching (larval release).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.27-32
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• 2012

Since LED lights have advantages of long life, low-carbon and high efficiency, they have been widely used as household lamps, automotive lighting, traffic lights etc. In this study, MCPCB LED lamps for automotive LED headlights were manufactured and the performance of heat release was optimized. The developed LED headlight satisfied the target thermal performance with heat pipes and fans, and it was also shown that fan life can be prolonged three times by fan on-off control.

• Natural Product Sciences
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• v.2 no.1
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• pp.29-36
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• 1996

This study was to evaluate the antitumor and immunopotentiation effects of Manda Enzyme (ME). Oral administration of ME (0.2ml/mouse) to tumor bearing mice significantly prolonged survival rate compared to the control group with the prolongation ratio of 40%. The inhibition ratios for the first and the second experiments were 51.8% and 26.4%, respectively. Only the spleen index was significantly increased in the MEF-treated group, but not in the control group. Gamma globulin level of the MEF-treated group was elevated when mice were injected with sarcoma-180 cells on the left groin. Activities of natural killer (NK) and lymphokineactivated killer (LAK) cells were observed by $^{51}Cr-release$ method. Activities of NK cell against YAC-1 cells were significantly increased in the MEF treated group. And LAK cell activities against P815 cells were also significantly increased in the experimental group. These observations, therefore, suggest that ME may have an anticancer effect and immunopotentiating effect in vivo.