• 제목/요약/키워드: Controlled Release

검색결과 584건 처리시간 0.031초

SiOC 매트(Mat)를 이용한 열전지용 전해질 격리판 제조 및 특성 (Properties of the Electrolyte Separators for Thermal Batteries Using SiOC Mat)

  • 임경훈;조광연;류도형;신동근;진은주;김현이;정해원;이홍림
    • 한국세라믹학회지
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    • 제46권6호
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    • pp.648-652
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    • 2009
  • Ceramic fiber separator is the promising material for thermal battery system because it reduces the production cost and offers the potential to a new application compared to a pellet type electrolyte. The electrolyte separator for thermal battery should be easily handled and loaded a large amount of the molten lithium salt. Ceramic fibers were used as an electrolyte separator and the lithium based molten salts were infiltrated into the ceramic filters. Leakage of molten salt (several lithium salts) leads to short-circuit during the thermal battery operation. In this study, a uniform and fine SiOC mat with fibers ranging from 1 to 3 ${\mu}m$ was obtained by electrospinning of polycarbosilane and pyrolysis. The optimum spinning conditions for obtaining fine diameters of SiOC fiber were controlled by the solution composition and concentration, applied voltage and spinning rate, release rate by porosity. The pore structures of the ceramic filter and the melting properties of the lithium salts affected to the electrolyte loading and leakage. The importance of the fiber size and porosity and their control was discussed and the mechanical properties were also discussed.

Effects of γ-aminobutyric acid-enriched fermented sea tangle (Laminaria japonica) on brain derived neurotrophic factor-related muscle growth and lipolysis in middle aged women

  • Choi, Wook-chul;Reid, Storm N.S.;Ryu, Je-kwang;Kim, Yunsook;Jo, Young-Hong;Jeon, Byeong Hwan
    • ALGAE
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    • 제31권2호
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    • pp.175-187
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    • 2016
  • This study evaluated the effects of γ-aminobutyric acid (GABA)-enriched fermented sea tangle (GFST), as a functional food, on brain derived neurotrophic factor (BDNF)-related muscle growth and lipolysis, in a sarcopenic obesity high-risk group. Twenty-one middle-aged women (53-63 y) participated in this randomized, double-blind, placebo controlled study. Participants ingested either 1,000 mg of GFST (n = 10) or a sucrose placebo (CON) (n = 11) everyday, for 8 weeks. Subjects were asked to abstain from any regular exercise. Fasting venous blood samples, body composition and muscular strength were measured before and after supplementation period. Collectively, we demonstrated that GFST significantly decreased total fat mass and triglyceride in body composition, as well as significantly increasing serum BDNF (p < 0.001), angiotensin converting enzyme (p < 0.001), human growth hormone and insulin-like growth factor-1 levels (p < 0.05 and p < 0.05, respectively) accompanied by increased total lean mass (p < 0.01). Furthermore, the reported improvements in total work, knee extension and flexion at 60° s−1 (p < 0.05), and peak torque normalized to body weight of knee flexion at 60° s−1 (p < 0.05), support an ergogenic effect of GABA associated with increased growth factor levels. The use of GFST, as a functional food ingredient, to elicit anti-obesity effects and stimulate the release of muscle-related growth factors with increasing serum BDNF levels may provide a protective intervention for age-related degeneration such as sarcopenic obesity.

Rapid Screening of Salmonella spp. Using PBM BioSignTM Salmonella Test and Evaluation of the PBMS Test

  • Lim, J.Y.;Kwon, N.H.;Kim, J.M.;Jung, W.K.;Park, K.T.;Hong, S.K.;Park, Y.H.
    • Asian-Australasian Journal of Animal Sciences
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    • 제17권12호
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    • pp.1746-1750
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    • 2004
  • The PBM ${BioSign}^{TM}$ Salmonella (PBMS) test kit based on an mmunochromatographic method was evaluated for the screening of Salmonella spp. in pure cultures, and 80, 15, and 10 artificially and naturally contaminated, and negative controlled food samples, respectively. The PBMS test involves presumptive qualitative procedures, detecting the presence of Salmonella spp. in foods within 26 h total testing period and allowing the user to release negative products 70 h earlier than the conventional methods. The PBMS test using Buffered Peptone Water and Rappaport-Vassiliadis broth was evaluated for 10 different food types for various Salmonella spp. It showed detection limits of 1 to 25 colony forming units (CFU)/25 g. No cross-reaction was observed, particularly to other gramnegative bacteria. These results indicate the PBMS test is a rapid and inexpensive procedure for the screening of Salmonella spp. present at low concentrations (1 to 25 CFU/25 g) in foods.

열처리한 교정용 호선의 기계적 성질과 금속유리에 대한 연구 (THE EFFECTS OF HEAT TREATMENT ON MECHANICAL PROPERTIES AND METAL RELEASE FROM HEAT-TREATED ORTHODONTIC ARCHWIRES)

  • 최철민;이병태
    • 대한치과교정학회지
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    • 제20권2호
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    • pp.381-390
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    • 1990
  • The purpose of this study was to evaluate the effects of heat treatment on mechanical properties in $0.016^{{\prime}{\prime}}{\times}0.022^{{\prime}{\prime}}$ blue Elgiloy wires and to measure the amounts of nickel and chromium released from the wires in artificial saliva. Ultimate tensile strength, yield strength and elongation were measured with universal testing machine (Instron). and the amounts of nickel and chromium released from the sample were measured with atomic absorption spectrophotometer after one week immersion in the artificial saliva. Ultimate tensile strength and yield strength were progressively increased below $1000^{\circ}F$, but elongation was decreased. And the results were reversed above $1100^{\circ}F$. After heat treatment of the sample for 9 minutes at $1000^{\circ}F$, the maximum tensile strength and yield strength were $213.6kg/mm^2$, $140.1kg/mm^2$, respectively. Both tensile strength and yield strength were decreased progressively above $1100^{\circ}F$. Elongation was appeared the minimum value (8.6%) after heat treatment for 9 minutes and 12 minutes at $1000^{\circ}F$. There was a pronounced increase in nickel and chromium liberation with increasing time and temperature. The maximum amounts of nickel and chromium released form the sample were $4.947{\mu}m/cm^2$, $3.088{\mu}g/cm^2$, respectively after heat treatment for 12 minutes at $1300^{\circ}F$. Heat treatment is applied to orthodontic wires, especially cobalt-chromium alloys, for the purpose of stress-relievning and hardening. When the heat-treatment of orthodontic wires, the heating procedure should be well controlled in order to have no effect on corrosion resistance and mechanical properties.

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수 종의 생분해성 국소약물 송달제제가 치주염 치료에 미치는 효과 (Effects of Several Biodegradable Controlled-Release Local Delivery Drugs on the Treatment of Periodontitis)

  • 양대승;유경태;피성희;이명연;유용욱;유형근;신형식
    • Journal of Periodontal and Implant Science
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    • 제29권4호
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    • pp.725-737
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    • 1999
  • The present study was performed to evaluate the clinical effects following local application of 30% minocycline strip(polycaprolactone), 2% minocycline gel(hydrocarbon gel) and 12% minocycline strip(polylactide, Minodent) to augment scaling and root planing in patients with chronic adult periodontitis. Forty teeth with periodontitis were enrolled in the study anddistributed into 4 groups including control group. All patients performed standardized oral hygiene instructions and mechanical debridement at the beginning of the study and then each local delivery drugs were inserted into periodontal pocket in each groups. Examinations regarding plaque index(PI), papillary bleeding index (PBI), probing pocket depth (PPD) were carried out at 0, 2, 4 weeks. All experimental groups showed statistically significant differences between baseline and 2 and 4 weeks in every clinical indices. Especially, 30%minocycline strip and Minodent group showed a significant improvement in PBI at 2 weeks and in PPD at 2 and 4 weeks. In conclusion, highly bio-resorbable Minodent delivered subgingivally as an adjunct to scaling and root planing induces better clinical effects for periodontal health than 2% minocycline gel and control group.

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Dependence Potential of Quetiapine: Behavioral Pharmacology in Rodents

  • Cha, Hye Jin;Lee, Hyun-A;Ahn, Joon-Ik;Jeon, Seol-Hee;Kim, Eun Jung;Jeong, Ho-Sang
    • Biomolecules & Therapeutics
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    • 제21권4호
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    • pp.307-312
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    • 2013
  • Quetiapine is an atypical or second-generation antipsychotic agent and has been a subject of a series of case report and suggested to have the potential for misuse or abuse. However, it is not a controlled substance and is not generally considered addictive. In this study, we examined quetiapine's dependence potential and abuse liability through animal behavioral tests using rodents to study the mechanism of quetiapine. Molecular biology techniques were also used to find out the action mechanisms of the drug. In the animal behavioral tests, quetiapine did not show any positive effect on the experimental animals in the climbing, jumping, and conditioned place preference tests. However, in the head twitch and self-administration tests, the experimental animals showed significant positive responses. In addition, the action mechanism of quetiapine was found being related to dopamine and serotonin release. These results demonstrate that quetiapine affects the neurological systems related to abuse liability and has the potential to lead psychological dependence, as well.

Timed Artificial Insemination or Embryo Transfer using CIDR, Estradiol Benzoate and Prostaglandin $F_{2{\alpha}}$ for the Rebreeding of Korean Native Donor Cattle

  • Son, Dong-Soo;Choe, Chang-Yong;Cho, Sang-Rae;Choi, Sun-Ho;Kim, Hyun-Jong;Lee, Je-In;Kim, Ill-Hwa
    • 한국수정란이식학회지
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    • 제23권2호
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    • pp.81-86
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    • 2008
  • This study compared the pregnancy rates of Korean native donor cattle after either a timed artificial insemination (TAI) or embryo transfer (TET) following the synchronization of ovulation using a controlled internal drug release (CIDR) device together with estradiol benzoate (EB) and prostaglandin $F_{2{\alpha}}$ ($PGF_{2{\alpha}}$). Fifty five cows and 8 heifers which had been previously used for embryo production were assigned to two treatments: (1) Thirty-two cattle received a CIDR device and 2 mg EB (Day 0), 25 mg $PGF_{2{\alpha}}$ injection at the time of CIDR removal on Day 7, and 1 mg EB injection on Day 8. All of the cattle received a TAI 30 h (Day 9) after the second EB injection (TAI group). (2) Thirty-one cattle received the same hormonal treatments as in the TAI group. The cattle with corpus luteum (CL) received a TET on Day 16 using frozen-thawed embryos (TET group). Ultrasonographic observations demonstrated that the proportion of cattle with synchronized ovulation on Day 10 and the concomitant formation of new CL on Day 13 did not differ between groups (p>0.05); the overall mean rates were 65.1 and 73.0%, respectively. The conception and pregnancy rates did not differ (p>0.05) between the TAI (12.5% and 12.5%) and TET groups (13.0% and 9.7%), respectively. We conclude that the pregnancy rate following TAI or TET in Korean native donor cattle was poor, which might be due in part to a poor synchrony of ovulation and concomitant CL formation.

Comparison of Embryo Production Performance and Conception Rate after Embryo Transfer between Mongolian Cattle and Korean Native Cattle

  • Chuluundorj, Gantugs;Lee, Ho-Jun;Son, Dong-Soo;Ganbaatar, Enkhmanlai;Tumur, Baldan;Yoon, Jong-Taek
    • 한국수정란이식학회지
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    • 제32권4호
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    • pp.319-324
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    • 2017
  • This study is to compare the effect of estrus synchronization and embryo transfer between Korean and Mongolian cattle. Embryos were collected from 9 donors housed in Asan city in South Chungcheong Province, South Korea. Embryos were collected 9 donors from Khushaat sum, Selenge province and Bayanchandmani sum, Tov province in Mongolia. Follicle Stimulating Hormone (FSH), Controlled Internal Drug Release (CIDR) and Prostaglandin (PG) were used for superovulation. Subsequently, Artificial Insemination (AI) was done for donor cow and embryo was collected after 7 and 8 days. Collected embryos were compared between Mongolian and Korean cattle. Finally, good quality and fresh embryos were transferred to 50 and 22 recipients of cows in Korea and Mongolia respectively. The findings show that Korean native cattle each donor cow produced on an average 16.9 embryos and, 10.9 embryos were found transferable. But in case of Mongolia the average production of embryos per donor cow was 8.6 embryos and, 6.2 embryos were found transferable. Embryo collection after 7 and 8 days was not difference in embryo production in Korea. But, in Mongolia embryo production after 8 days was found more efficient than the 7 days. Korean native recipient's cows (74.6%) and Mongolian recipient's cows (71.0%) respectively were found transferable ovarian stage. The result suggested that efficiency of embryo production from the superovulation method treated of Korean cow were higher than the Mongolian cow. The pregnancy rate of Korea native cattle was 72%, which was about 10% higher than that of Mongolia cattle.

Characterization of Dexamethasone-eluting PLGA Films Coated on Capsular Tension Ring to Prevent Posterior Capsule Opacification

  • Chang, Byung-Kon;Kim, Bo-Gyun;Kim, Young-Jae;Kang, Myung-Joo;Lee, Jae-Hwi;Choi, Young-Wook
    • Biomolecules & Therapeutics
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    • 제16권4호
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    • pp.425-430
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    • 2008
  • The objectives of this study were to prepare PLGA film onto the surface of the capsular tension ring (CTR) for controlled drug release and investigate the influence of plasticizers, the test drug and measurement conditions on flexibility of the film. Film solutions were prepared by dissolving PLGA, plasticizer (triethyl citrate, TEC or polyethylene glycol, PEG), test drug (dexamethasone) in ethyl acetate then films were prepared by spray coating and evaporation method. Then, the flexibility of PLGA film was determined by elongation test. The addition of plasticizer, PEG or TEC to PLGA copolymer caused a depression of glass transition temperature ($T_g$) and the elasticity of PLGA films increased. The addition of dexamethasone to the PLGA/TEC matrix decreased the flexibility of film. Dimensional factors of the PLGA films such as width and thickness were significantly influenced on flexibility of films and film length and elongation speed had no considerable influence on elongation of films. In this study, sufficiently flexible and stable PLGA films capable of being coated onto CTR could be prepared. This PLGA films can be used as a platform for local drug delivery.

양전자단층촬영에 이용 가능한 새로운 심근 혈류 추적자 개발; F-18이 표지된 유기암모늄염의 합성과 체내분포에 관한 연구 (Synthesis and $^{18}F$ Labelling of Organic Ammonium Salts to New Cardiac Flow Tracer for PET and Their Biodistribution)

  • 유국현
    • 대한핵의학회지
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    • 제28권3호
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    • pp.331-337
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    • 1994
  • In order to develop a $^{18}F$-labelled myocardial perfusion agent(flow tracer) for PET, $^{18}F$-labelled organic ammonium cations were synthesized and evaluated in relation to their biodistribution. Five quaternary organic ammonium compounds were labelled with $^{18}F$ in a side chain with moderate to good yields by direct introduction of $^{18}F$-fluoride. Radiochemical yields have been achieved in 30-40min by the precursors (tosylates) in dimethylsulfoxide 15-60% (decay corrected). The reaction was found to be autocatalyzed. A remote controlled procedure was developed in these synthesis. $^{18}F$-Labelling and HPLC-purification of com-pounds needed about 60 min(Yield; 7-20%). Up to now the two compounds N-4-[$^{18}F$]fluorobutyl-pyridinium cation(1) and N, N dibenzyl-4(2-[$^{18}F$]fluoroethyl)piperidinium cation(2) were investigated in relation to their biodistribution in mice. Compound 1 showed at 1 min post injection the high uptake of 19.22% ID/g organ in the myocardium but a following fast decline to 1.12% ID/g organ after 40min. Uptake of compound 2 was after 1min in the heart 5.90% ID/g organ but after 40min at the relative high value of 4.33% ID/g organ. Heart:blood ratio for compound(1) at 1 min was 8.3, at 40 min 2.6 for compound II 2.0(1min) and 15.0(40 min). As data of compound 2 showed greater heart uptake, slower myocardial release, and higher heart: blood ratios, compound 2 is a good candidate for further evaluation.

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