• Journal of Pharmaceutical Investigation
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• v.32 no.4
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• pp.267-275
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• 2002

A self-microemulsifying drug delivery system (SMEDDS) was developed to increase the dissolution rate, solubility, and ultimately bioavailability of a poorly water soluble drug, lovastatin. SMEDDS was thε mixtures of oils, surfactants, and cosurfactants, which emulsify under conditions of gentle agitation, similar to those which would be encountered in the gastro-intestinal (GI) tract. Various types of self-emulsifying formulations were prepared using four types of oil (Capryol 90, Lauroglycol 90, Labrafil M 1944 CS and Labrafil M 2125), two surfactants (Cremophor EL and Tween 80), and three cosurfactants (Carbitol, PEG 400 and propylene glycol). Thε efficiency of emulsification was studied using a laser diffraction size analyzer to determine particle size distributions of the resultant emulsions. Optimized formulations selected for bioavailability assessment were Carpryol 90 (40%), Cremophor EL (30%) and Carbitol (30%). SMEDDS containing lovastatin (20 mg and 5 mg) were compared to a conventional lovastatin tablet $(Mevacor^{\circledR},\;20\;mg/tab)$ by the oral administration as prefilled hard gelatin capsules to fasted beagle dogs for in vivo study. The arεa under the serum concentration-time curve from time zero to the last measured time in serum, $AUC_{0{\rightarrow}24h}$, was significantly greater in SMEDDS, suggesting that bioavailability increase 130% and 192% by the SMEDDS, respectively. The self-emulsifying formulations of lovastatin afforded the improvement in absolute oral bioavailability relative to previous data of lovastatin tablet formulation. These data indicate the utility of dispersed self-emulsifying formulations for the oral delivery of lovastatin and potentially other poorly absorbed drugs.

• Journal of Environmental Science International
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• v.20 no.8
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• pp.943-951
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• 2011

We investigated the effects of temperature changes on the oxygen consumption rhythm in Japanese eels, Anguilla japonica, using an automatic intermittent flow respirometer (AIFR). The endogenous rhythm of the oxygen consumption rate (OCR) in the eels (n = 18; 44-74 cm, 145-690 g), freshly collected by bag net from estuaries, was nearly synchronous with the tidal pattern of the estuarine collection site. The magnitude of mean OCR (mOCR) of eels showed variable range of 82.2 - 116.5 ml $O_2\;kg^{-1}ww \;h^{-1}$ under constant conditions. In case of increasing temperature from 25 to $38^{\circ}C$, the OCR of eels exhibited a gradually increasing trend with a rhythmic pattern until $36^{\circ}C$. Above $36^{\circ}C$ the rhythms of the OCR dampened and the OCR decreased rapidly at around $36-37^{\circ}C$. The OCR of the eels exhibited the maximum value at $38^{\circ}C$, and then it sharply decreased. The results suggested that the critical thermal maximum (CTM) regarding the endogenous rhythms of the eels was at around $36-37^{\circ}C$ when water temperature increased at $0.5^{\circ}C$/14 h following the acclimation at $25^{\circ}C$. In case of decreasing temperature ($0.5^{\circ}C$/14 h) from 25 to $0^{\circ}C$, the OCR of the eels displayed a abrupt decrease up to $23^{\circ}C$, and between at 23 and $20^{\circ}C$, there was an agitation which showed a slight increase in the OCR with a duration of 1-2 days. Below $9^{\circ}C$, the OCR rhythm of the eels showed a constant state regardless of temperature decreasing. These results suggest that the Japanese eel has an upper incipient lethal temperature at $36^{\circ}C$, with a lower thermal limit at $9^{\circ}C$. The biochemical aspects of the eels influenced by water temperature need to be further studied.

• Korean Journal of Biological Psychiatry
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• v.20 no.3
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• pp.111-117
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• 2013

Objectives We investigated the effectiveness and safety when treated in schizophrenics with paliperidone palmitate, a long acting injectable antipsychotic. Methods This was a 24-week open-label study, performed at one center in Korea. The eligible patients with schizophrenia diagnosed by Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) criteria were enrolled. Patients received long-acting paliperidone palmitate injection (234 mg, baseline; 156 mg, week 1 ; then once 4 weeks flexible dosing). Effectiveness assessments were measured by the Positive and Negative Syndrome Scale (PANSS), The Clinical Global Impression Severity Scale (CGI-S), The Personal and Social Performance (PSP) at baseline, week 1, every 4 weeks untill 24 weeks or endpoint. Safety assessments were measured by The Extrapyramidal Symptom Rating Scale (ESRS), body weight (BW) and incidence of adverse events. Oral antipsychotics were stopped or tapered off within next 14 days. Results Of 20 patients recruited, 9 patients (45%) completed the study. Paliperidone palmitate produced a significant improvement in PANSS total score from baseline to endpoint. The response rate was 75% [mean change (${\pm}SD$) $-25.9{\pm}14.4$, all p < 0.001]. The CGI-S and PSP total scores significantly improved during 24 weeks (All p < 0.001). Eighty percent of patients reported adverse events and most common adverse events (${\geq}10%$) in paliperidone palmitate were anticholinergic adverse event, extrapyramidal symptoms, weight gain, akathisia, insomnia, headache, agitation, anxiety and GI trouble. ESRS score is not statistically significant, but tends to get better at the end of the study when compared to baseline. Conclusions Our study results demonstrated maintained effectiveness and safety of paliperidone palmitate treatment in schizophrenics. And provides both clinicians and patients with a new choice of treatment that can improve the outcome of long term therapy. Their potential effectiveness and safety should be better addressed by future randomized-controlled trials.

• Nuclear Engineering and Technology
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• v.28 no.1
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• pp.1-16
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• 1996

In an effort to determine the combined effects of major parameters of heat exchanger tubes on the nucleate pool boiling heat transfer in the scaled in-containment refueling water storage tank (IRWST), a total of 1,966 data for q'quot; versus ${\Delta}T$ has been obtained using various combinations of tube diameters, surface roughness, and tube orientations. The experimental results show that (1) increased surface roughness enhances heat transfer for both horizontal and vertical tubes, (2) the two heat transfer mechanisms, i.e.,enhanced heat transfer for both horizontal and vertical tubes, (2) the two heat transfer mechanisms, i.e., enhanced heat transfer due to liquid agitation by bubbles generated and reduced heat transfer by the formation of large vapor slugs and bubble coalescence are different in two regions of low heat fluxes (q'quot; $\leq$50kW/$m^2)$ and high heat fluxes (q'quot; $\geq$50kW/$m^2)$ depending on the orientation of tubes and the degree of surface roughness, and (3) the heat transfer rate decreases as the tube diameter is increased for both horizontal and vertical tubes, but the effect of tube diameter on the nucleate pool boiling heat transfer for vertical tubes is greater than that for horizontal tubes. Two empirical heat transfer correlations for q'quot;, one for horizontal tubes and the other for vertical tubes, are obtained in terms of surface roughness $({\varepsilon})$ and tube diameter (D). In addition, a simple empirical correlation for nucleate pool boiling heat transfer coefficient $(h_b)$ is obtained as a function of heat flux (q'quot;) only.ucleate pool boiling heat transfer coefficient $(h_b)$ is obtained as a function of heat flux (q'quot;) only.

• Korean Chemical Engineering Research
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• v.45 no.4
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• pp.400-409
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• 2007

Morphology of methane/propane clathrate hydrate crystal was investigated under different undercooling conditions. After the water pressurized with compound guest gas was fully saturated by agitation, medium within the vessel was rapidly undercooled and maintained at the constant temperature while the visual observations using microscope revealed detailed features of subsequent crystal nucleation, migration, growth and interference occurring within liquid pool. The growth of hydrate was always initiated with film formations at the bounding surface between bulk gas and liquid regions under all tested experimental conditions. Then a number of small crystals ascended, some of which settled beneath the hydrate film. When undercooling was relatively small, some of the settled crystals slowly grew into faceted columns. As the undercooling increased, the downward growth of crystals underneath the hydrate film became dendritic and occurred with greater rate and with finer arm spacing. The shapes of the floating crystals within liquid pool were diverse and included octahedron and triangular or hexagonal platelet. When the undercooling was small, the octahedral crystals were found dominant. As the undercooling increased, the shape of the floating crystals also became dendritic. The detailed growth characteristics of floating crystals are reported focused on the influences caused by undercooling and memory effect.

• Journal of Dental Anesthesia and Pain Medicine
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• v.22 no.5
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• pp.357-367
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• 2022

Background: Low-dose dexmedetomidine may be a suitable alternative to opioids for pediatric ambulatory procedures under general anesthesia (GA). However, the recovery profile remains unclear. Herein, we aimed to evaluate the effects of low-dose dexmedetomidine on the recovery profile of children. Methods: Seventy-two children undergoing ambulatory oral rehabilitation under GA were randomly and equally distributed into two groups (D and F). Group D received an infusion of dexmedetomidine 0.25 ㎍/kg for 4 min for induction, followed by maintenance of 0.4 ㎍/kg/h. Group F received an infusion of fentanyl 1 ㎍/kg over 4 min for induction, followed by maintenance at 1 ㎍/kg/h. The primary outcome was the extubation time. The secondary outcomes were awakening time, end-tidal sevoflurane (ET-Sevo) requirement, change in hemodynamic parameters, Richmond Agitation-Sedation Scale (RASS), Children's Hospital of Eastern Ontario pain scale (CHEOPS) score, length of PACU stay, and incidence of adverse events. Results: Statistically significant differences were observed in the recovery profile between the groups: the median time for extubation was 3.65 (3.44-6.2) vs. 6.25 (4.21-7) minutes in groups D vs. F (P=0.001), respectively, while the corresponding awakening times were 19 (18.75-21) and 22.5 (22-24) minutes, respectively (P < 0.001). The mean ET-Sevo was low in group D (1.1 vs. 1.2; P < 0.001). The heart rate was significantly low across all time points in group D, without resulting in bradycardia. The median RASS and CHEOPS scores were also significantly lower in group D. No significant differences were observed in the mean arterial pressure, incidence of adverse events, or length of PACU stay. Conclusion: Low-dose dexmedetomidine was more effective than fentanyl as an opioid substitute at providing a better recovery profile in pediatric ambulatory oral rehabilitation under GA. Dexmedetomidine also significantly reduced sevoflurane consumption without causing adverse events or prolonging hospital stay.

• Food Science and Preservation
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• v.30 no.1
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• pp.132-145
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• 2023

In this study, culture conditions were optimized to confirm the feasibility of Acetobacter pasteurianus as a starter for fermentation vinegar. Acetobacter pasteurianus strain can be used as a food ingredient. The optimal temperature and pH conditions of the selected Acetobacter pasteurianus SRCM101388 were 28℃ and pH 6.00, respectively. The response surface methodology (RSM) was used to optimize the composition of the medium, and Plackett-Burman design (PBD) was used to obtain the effective selection of culture medium, resulting in that glucose, sucrose, and yeast extract had the highest effect on increasing biomass. The optimal concentration, which was performed by central composite design (CCD), were determined to be 10.73 g/L of glucose, 3.98 g/L of sucrose, and 18.73 g/L of yeast extract, respectively. The optimal concentrations of trace elements for the production of biomass were found to be 1 g/L of ammonium sulfate, 0.5 g/L of magnesium sulfate, 2 g/L of sodium phosphate monobasic, 2 g/L of sodium phosphate dibasic, and the final optimized medium was pH 6.10. When incubated in a 5 L jar fermenter, the SRCM101388 strain showed a faster-dissolved oxygen (DO) reduction at a lower agitation rate (rpm), and it was able to grow even at reduced DO level when aeration was maintained. The amount of final biomass produced was 2.53±0.12×10⁹ CFU/mL (9.40±0.02 log CFU/mL) when incubated for 18 hours at 150 rpm, 0.5 vvm, pH 6.0, and 28℃.

• KSBB Journal
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• v.23 no.3
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• pp.257-262
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• 2008

In this study, the reaction conditions for lipase-catalyzed resolution of racemic naproxen 2,2,2-trilfluoroethyl thioester were optimized, and the effect of surfactants was investigated. Among the organic solvents tested, the isooctane showed the highest conversion (92.19%) in a hydrolytic reaction of (S)-naproxen 2,2,2-trifluoroethyl thioester. In addition, the isooctane induced the highest initial reaction rate of (S)-naproxen 2,2,2-trifluoroethyl thioester ($V_s=2.34{\times}10^{-2}mM/h$), the highest enantioselectivity (E = 36.12) and the highest specific activity ($V_s/(E_t)=7.80{\times}10^{-4}mmol/h{\cdot}g$) of lipase. Furthermore, reaction conditions such as temperature, concentration of the substrate and enzyme, and agitation speed were optimized using response surface methodology (RSM), and the statistical analysis indicated that the optimal conditions were $48.2^{\circ}C$, 3.51 mM, 30.11 mg/mL and 180 rpm, respectively. When the optimal reaction conditions were used, the conversion of (S)-naproxen 2,2,2-trifluoroethyl thioester was 96.5%, which is similar to the conversion (94.6%) that was predicted by the model. After optimization of reaction conditions, the initial reaction rate, lipase specific activity and conversion of (S)-naproxen 2,2,2-trifluoroethyl thioester increased by approximately 19.54%, 19.12% and 4.05%, respectively. The effect of surfactants such as Triton X-100 and NP-10 was also studied and NP-10 showed the highest conversion (89.43%), final reaction rate of (S)-naproxen 2,2,2-trifluoroethyl thioester ($V_s=1.175{\times}10^{-2}mM/h$) and enantioselectivity (E = 59.24) of lipase.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.3
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• pp.75-86
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• 2003

In the near future, the capacity of conventional anaerobic digester is thought to be insufficient because of the increase of the total solids from expansion of intercepting sewer, sewage quantity and direct input of night soil from near apartment districts. The objectives of this study was to investigate the improvement of digestion efficiency using microbial agent(Bio-dh). The system was a pilot-scale, two-staged, anaerobic sludge digestion system. The first-stage digester was heated and mixed. The agitation velocity of the first-stage digester was 120rpm. The second-stage digester was neither heated nor mixed. The Digestion temperature was kept at $35{\pm}1^{\circ}C$ The detention time of digester was 19 days. The dosage of sewage sludge and microbial agent were $0.65m^3/day$ and $0.5{\ell}/day$, respectively. The experiments was run for 25days. Three times a week, $COD_{Mn}$ and SS of effluent, TS, VS, and biogas production rate were measured. Temperature, pH, and alkalinity were measured daily. The results were as follows ; Without microbial agent, digestion efficiencies ranged 46.0%~50.9%(mean=48.6%), with microbial agent(Bio-dh), digestion efficiencies ranged 52.8%~57.3%(mean=54.2%). Consequently, microbial agent(Bio-dh) increased the sludge digestion efficiency about 12%. Also, Without microbial agent, the mean concentration of $COD_{Mn}$ and SS of second-stage digester effluent were 1,639mg/L, 4,888mg/L respectively. With microbial agent, the mean concentration of $COD_{Mn}$ and SS of second-stage digester effluent were 859mg/L, 2,405mg/L respectively. Consequently, microbial agent(Bio-dh) increased the removal efficiency of $COD_{Mn}$ and SS about 47.6% and 50.8%, respectively.

• Microbiology and Biotechnology Letters
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• v.34 no.1
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• pp.7-14
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• 2006

Feather, generated in large quantities as a byproduct of commercial poultry processing, is almost pure keratin, which is not easily degradable by common professes. Four strains, SMMJ-2, FL-3, NO-4 and RM-12 were isolated from soil for production of extracellular keratinolytic protease. They were identified as Bacillus sp. based on their morphological and physiological characteristics. They shown high protease activity on 5.0% skim milk agar medium and produced a substrate like mucoid on keratin agar medium. Bacillus sp. SMMJ-2 had a faster production time for producing keratinolytic protease than other strains. This strain did not completely degrade whole chicken feather for five days in basal medium but completely degraded whole chicken feather when supplied with nitrogen source for 40hours in keratinolytic producing medium ($0.7%\;K_{2}HPO_{4},\;0.2%\;KH_{2}PO_{4},\;0.1%$ fructose, 1.2% whole chicken feather, $0.01%\;Na_{2}CO_3$, pH 7.0). When supplied with chicken feather as nitrogen source, keratinolytic protease activity was 89 units/ml/min. When soybean meal was used as nitrogen source, the keratinolytic protease production reached a maximum of 106 units/ml/min after 48 hours under $30^{\circ}C$, 180 agitation. To isolate the keratinolytic protease, the culture filtrate was precipitated with $(NH_4)_{2}SO_4$ and acetone. The recovery rate of keratinolytic protease was about 96% after treatment with 50% acetone. The enzyme was stable in the range of $30{\sim}50^{\circ}C$ and pH $6.0{\sim}12.0$.