• 제목/요약/키워드: Control release

검색결과 1,466건 처리시간 0.031초

CaO2 적용에 따른 퇴적물의 P fraction 변화와 수질에 미치는 영향 (The Effect of CaO2 Application on the Change of Sedimentary Phosphorus Fraction and Water Quality)

  • 김범근;모하메드아케트키룰;권성현
    • 한국환경과학회지
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    • 제28권5호
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    • pp.511-520
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    • 2019
  • This study was investigated to improve the phosphorus release and water quality by transformation of sedimentary P fraction for application of $CaO_2$. For the experiment, 0.5% (w/w) of $CaO_2$ was homogenized in the sediment and incubated with the control for 20 days. The analytical results showed that pH increased with $CaO_2$ and redox potential (ORP) was improved in the sediment of the reactor. The growth rate of chlorophyll-a was lower in the $CaO_2$ reactor and Dissolved Oxygen (DO) of overlying water maintained higher than that of the control. Total phosphorus (T-P) concentration in the overlying water increased from the initial concentration to 0.304mg/L in the control at 20 days. The reactor of $CaO_2$ was lowered by 29.3%. Ex-P, Fe-P and Ca-P in sediment P fraction were increased with the $CaO_2$. The formation of bound Fe-P and Ca-P in the sediments seemed to control the release of P by removing the Soluble Reactive Phosphorus (SRP) presented in the pore water. From the result, this indicated that the reduction of P release from the sediments seems to be effective in suppressing the eutrophication of P and improving the oxygen condition in the water quality with the application of $CaO_2$.

친환경 딸기 재배 농가에서 칠레이리응애를 이용한 점박이응애 생물적 방제 (Biological Control of Two Spotted Spider Mite (Tetranychus urticae) by the Predatory Mite (Phytoseiulus persimilis) in Sustainable Strawberry Fields)

  • 김도익;김선곤;신길호;서종분;최경주;임경호;김상수
    • 한국유기농업학회지
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    • 제14권3호
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    • pp.315-323
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    • 2006
  • 전남지역 딸기 친환경재배농가에서 큰 피해를 주고 있는 점박이응애를 방제하기 위해 천적인 칠레이리응애의 방사량과 횟수를 검정하고, 농가에서의 실증효과를 시험하였다. 칠레이리응애를 1회 방사하였을 때 방사 4주째부터 밀도가 올라가기 시작하였으며, 2회 방사시에는 7주 이후 8주째부터 밀도 증가가 이루어 졌다. 그러나 3회 방사하였을 때에는 조사기간 동안 점박이응애 밀도를 10마리 내외로 일정하게 유지시킬 수 있었다. 또한 칠레이리응애의 방사량도 1,000마리인 경우에는 생육 후기에 점박이응애의 밀도가 증가하여 방제효과가 낮았으며, 3,000마리를 방사하는 경우에는 2,000마리 처리구와 비슷한 밀도를 유지하는 것으로 보아 천적을 2,000마리 방사하여 점박이응애를 충분히 억제할 수 있었다. 함평 농가실증 시험의 무방사구에서 점박이응애는 3월 하순부터 발생하기 시작하여 이후 급격한 밀도 증가가 이루어졌다. 방사구에서는 칠레이리응애 밀도가 지속적으로 유지되어 점박이응애 밀도를 억제하였다. 보성 농가에서는 3월 상순에 방사구의 점박이응애 밀도가 상승함에 따라 칠레이리응애 밀도도 함께 상승하여 3월 하순에는 10엽당 50마리까지 증가하였다. 발생엽율은 천적 방사구에서는 높지 않았으나 무방사구에서는 초기 밞생이 확인된 이후 계속 상승하여 $10.5{\sim}75.5%$까지 올라갔다.

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Testosterone 처리한 미성숙 무지개송어 뇌하수체의 세포배양계에서 생식소자극초르몬 분비에 대한 Activin의 효과 (Effects of Activin on Testosterone-primed Immature Rainbow Trout Gonadotropin Release in vitro)

  • 김대중;한창희;회전승미
    • 한국수산과학회지
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    • 제32권2호
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    • pp.204-210
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    • 1999
  • 본 연구에서는 GTH I과 II의 분비조절기구을 밝히기 위하여 T을 경구투여한 미성숙 무지개 송어의 뇌하수체 세포배양계를 이용하여, activin에 의한 GTH I과 II의 분비량을 RIA로 조사하였다. 그 결과, T의 positive feedback에 의해 뇌하수체내 GTH II 함량이 증가하였으나, 뇌하수체내 GTH I 함량는 T에 의해 영향을 받지 않았다. 이러한 뇌하수체를 이용한 세포배양 실험에서, 장시간 (3 일간)의 activin 처리에 의해 GTH II 분비량은 증가하였지만, 단시간 (24시간)의 activin 처리에 의해 GTH II 분비량은 영향을 받지 않았다. 또한 activin의 자극에 의해서 분비된 GTH II 분비량은 DA에 의해 부분적으로 억제되었지만, sG-nRH의 자극에 의해서 분비된 GTH II는 DA에 의해 완전히 억제되었다. activin의 자극에 의해서 분비된 GTH II는 부분적으로 억제되었다. 그러나 activin으로 전처리에 의해 방출된 GTH II 분비량은 sGnRH 자극에 의한 증폭현상은 나타나지 않았다. 한편 GTH I 분비는 본 실험에서 사용된 호르몬에 의해서 영향을 받지 않았다. 이상의 결과들을 종합해보면, GTH I과 II는 서로 다른 합성기구에 의해 조절되며, T에 의해 GnRH, activin 그리고 DA 수용체의 감수성이 발현되어 GTH II 분비를 조절하였다. 그러나 GTH I의 분비조절 기구는 차후 계속해서 연구되어야 할 것으로 판단된다.

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외용겔 및 다중유제크림의 코지산 방출특성과 피부자극성 (Drug Release Characteristics and Skin Irritancies of Topical Gels and Multiple Emulsion Creams Containing Kojic Acid)

  • 유성운;박은우;최영욱
    • Journal of Pharmaceutical Investigation
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    • 제28권2호
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    • pp.87-92
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    • 1998
  • Kojic acid (KA) is an antimelanogenic agent which has been widely used in cosmetics to whiten the skin color. However, it has the drawbacks of the skin irritancy and the instability against the pH, temperature, and light. In order to overcome these problems, various topical gels and multiple emulsion creams which can control the release of active ingredient, KA, were formulated employing cream bases of mineral oil with caprylic capric triglyceride and hydrophilic polymers such as chitosan, carbopol. and pluronics. Using Franz diffusion cells mounted with a synthetic cellulose membrane (MWCO 12,000), drug release characteristics of the formulations were evaluated by the HPLC assay of KA concentration in the receptor compartment of pH 7.4 phosphate buffered saline solution. Drug release from chitosan-based gels (ChitoGel) obeyed to the first order kinetics with a rapid release especially in the initial period. However, pluronic-based gels (PluGel) and carbopol-based gels (CarboGel) revealed controlled release of drug to some extent, followed by the square root-time kinetics. Moreover, the release of KA was further controlled with the W/O/W multiple emulsion creams (MultiCream), showing the apparent zero order release kinetics by virtue of dynamic ratecontrolling membrane of the oil layer. The flux $(J,\;{\mu}g/cm^2/hr)$ of ChitoGel. CarboGel. PluGel. and MultiCream in the initial period of 6hr were 73.30, 28.67. 24.04 and 7.72, respectively. On the other hand, the skin irritancy score of ChitoGel and MultiCream were observed as 2.5 and 2.3 respectively, in the rabbit skin irritation test. Although there were insignificant differences at p<0.05 between those formulations, it was possible to conclude that the W/O/W multiple emulsion creams containing KA might be a good candidate for an antimelanogenic drug delivery system due to the controlled release of acidic drug molecules.

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Clinical Study on Fluvoxamine Combined with Oxycodone Prolonged-Release Tablets in Treating Patients with Moderate to Severe Cancer Pain

  • Xiao, Yang;Liu, Jun;Huang, Xin-En;Ca, Li-Hua;Ma, Yi-Min;Wei, Wei;Zhang, Rong-Xia;Huang, Xiao-Hong;Chang, Juan;Wu, Yi-Jia
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권23호
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    • pp.10445-10449
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    • 2015
  • Objective: To observe treatment effects and safety of fluvoxamine combined with oxycodone prolonged-release tablets in treating patients with moderate to severe cancer pain. Methods: Patients confirmed pathologically with cancer and complicated with moderate to severe pain, were divided into control and experimental groups. Oxycodone prolonged-release tablets, with or without fluvoxamine, were administrated to all study patients until pain relief. Degree of pain relief, dose of oxycodone prolonged-release tablets, side effects and quality of life were compared before and after treatment. Results: In total, 120 patients were recruited. No statistically significant difference was detected regarding age, gender, types of cancer, KPS between two groups of patients (P>0.05). Baseline pain score of patients with moderate pain in treatment and control group was $4.9{\pm}0.8$ and $5.1{\pm}0.8$, respectively; and decreased to $1.8{\pm}1.1$ and $1.2{\pm}1.1$ after treatment, respectively. Pain intensity was significantly reduced in the treatment group (P=0.028). Average daily consumption of oxycodone prolonged-release tablets was ($54.0{\pm}19.6$) mg and ($44.7{\pm}18.7$) mg respectively, which is lower in treatment grpup than in control group, but the difference was not statistically significant (P=0.065). Baseline pain score of patients with severe pain in treatment and control groups were $8.3{\pm}1.1$ and $8.3{\pm}1.1$, respectively; and pain intensity after treatment decreased to $2.9{\pm}1.0$ and $2.3{\pm}1.0$. Pain intensity was significantly reduced in the treatment group, with statistical significance (P=0.026). Average daily consumption of oxycodone prolonged-release tablets was ($132.0{\pm}42.2$) mg and ($110.7{\pm}33.9$) mg, respectively, which is lower in treatment group than in control group, and the difference was statistically significant (P=0.035). In terms of quality of life, patients in treatment group had better performance status, daily activity, mood, and sleep than that in control group (P < 0.05). Patients in two groups had similar side effects, eg., constipation, nausea/vomiting, lethargy, dizziness, itchy skin, dysuria, and ataxia. Lower incidence of nausea/vomiting, lethargy, was obtained from patients in treatment than in control group, while significant low constipation was observed in treatment than in control group (35.0% vs 49.2%, P=0.026). Conclusion: Fluvoxamine combined with oxycodone prolonged-release tablets could be more effective in treating patients with cancer pain, and could reduce the dosage of oxycodone prolonged-release tablets and thus be associated with lower side effects, and improved quality of life.

Dried Bacillus subtilis Culture Reduced Ammonia Gas Release in Poultry House

  • Santoso, U.;Ohtani, S.;Tanaka, K.;Sakaida, M.
    • Asian-Australasian Journal of Animal Sciences
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    • 제12권5호
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    • pp.806-809
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    • 1999
  • The present study showed the advantages of dried Bacillus subtilis culture (DBSC) supplementation on reducing ammonia gas release in the poultry house. In Experiment 1, 65-week-old Hyline W-36 hens were raised in individual wire-floor cages in a windowless house, and divided into two groups of 180 hens each. One group was fed diets without DBSC as the control and another group was fed a diet supplemented with 2% DBSC. In Experiment 2, 2-week-old broiler chicks were divided into 3 treatment groups of 20 chicks each and maintained in individual floor cages. One group was fed the diet without DBSC and other two groups were fed the diet supplemented with 1 or 2% DBSC, respectively. In experiment 1, DBSC consistently reduced ammonia gas release in the laying house (p<0.01) and manure storage facilities (p<0.01). incubation of feces for 1, 2, 3, 4, 5, 6, 24 or 48 hours showed that DBSC consistently reduced ammonia gas release. In Experiment 2, DBSC reduced ammonia gas release in the broiler house; however, DBSC had no effect on total N, urate-N and ammonia-N contents of feces, but it improved cumulative N utilization and decreased serum urea-N concentration when chicks when chicks were fed 1% DBSC.

모래 캡핑 두께가 퇴적물 인 용출에 미치는 영향 (Impact of Thickness of Sand Capping on Phosphorus Release Rate from Sediment)

  • 정우혁;김건하
    • 생태와환경
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    • 제39권3호통권117호
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    • pp.331-339
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    • 2006
  • 본 연구는 퇴적물의 인 용출을 제어하기 위한 방법으로 모래를 이용한 캡핑을 포설할 경우 두께에 따른 인 용출율 저감 효과를 파악하기 위하여 수행되었다. 캡핑은 퇴적물의 인이 수체로 용출되는 속도를 저감시키며, 미생물의 기질소모 이하로 그 속도를 낮추면 수체내의 인의 농도를 일정하게 유지할 수 있음을 알 수 있었다. 모래캡핑의 두께와 용출저감은 선형의 상관관계를 보이며 캡핑 두께가 40 mm에서 80 mm로 두꺼울수록 탈산소계수가 0.311 $day^{-1}$에서 0.262 $day^{-1}$으로 작아지고 있으며, 두께가 증가함에 따라 재폭기 계수는 0.013 $day^{-1}$에서 0.0240 $day^{-1}$으로 커지는 것으로 나타났다. 회귀분석한 결과에 의하면 최소한 20${\sim}$40 mm의 모래캡핑을 실시하더라도 인 용출량을 효율적으로 저감 시킬 수 있는 것으로 나타났다.

Cortex Mori Inhibits the CGG-specific IgE-Dependent Histamine Release

  • Chai, Ok-Hee;Kyoung, Jin-Kang;Park, Myoung-Hee-;Lee, Moo-Sam-;Jun, Byoung-Deuk
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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    • pp.244-244
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    • 1994
  • Cortex Mori, the root bark of mulbery tree has been used as an antiphlogistic, diuretic, and expectorant in herbal medicine. The purpose of this study is to evaluate chicken gamma globulin (CGG)-specific IgE-induced morphologic and functional changes in rat peritoneal mast cells (RPMC), and to determine whether Cortex Mori could inhibit the CGG-specific IgE-depeildent mast cell degranulation and histamine release from RPMC. Results are 1) the degranuration and histamine release from RPMC were not induced within 1 hour after addition of Cortex Mori alone, 2) the CGG and CGG-specific IgE-Induced degranulation from RPMC was observed within 10 minutes, 3) the histamine release from RPMC sensitised with CGG-specific IgE was induced by tile addition of CGG, 4) CGG-specific IgE-dependent degranulation rate in RPMC pretreated with Cortex Mori was significantly Inhibited, compared to that of control group without Cortex Mori pretreatment, and 5) the CGG-specific IgE-dependent histamine release from RPMC was significantly inhibited by pretreatment with Cortex Mori. These data suggest that Cortex Mori contains some substances with capabilities to inhibit CGG-specific IgE-dependent degranulation and histamine release from RPMC.

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염산 탐스로신을 함유하는 방출제어형 제제의 제조 및 용출거동 (Preparation and Dissolution Profiles of Controled Release Formulations Containing Tamsulosin Hydrochloride)

  • 윤재남;김정수;김동우;이계원;지웅길
    • Journal of Pharmaceutical Investigation
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    • 제35권6호
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    • pp.445-451
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    • 2005
  • As a selective ${\alpha}_{1A}-adrenoreceptor$ antagonist, tamsulosin has been used clinically for urinary obstructed patients with benign prostatic hyperplasia. The single and multi-layered pellets containing tamsulosin hydrochloride were prepared in an effort to control the drug release, avoiding dose-dependent side effects of tamsulosin hydrochloride upon oral administration. The drug release from multi-layered pellets was substantially controlled, compared with single layered pellets. The drug release from coated pellets with single or multi layer was affected by the nature of coating agent, the percentage of coating level and the presence of hydrophilic material in coating layer. In conclusion, the controlled release oral delivery system using multi-layered pellet is very useful for tamsulosin hydrochloride, resulting in improvement of patient compliance and therapeutic drug levels for a longer period of time.

저질토로부터의 인의 용출거동 예측 및 제어기술 개발 - I. 저질토로부터의 인의 용출거동 예측 (Prediction of Phosphorus Transport from Sediment and Development of Phophorus Control Technology - I. Prediction of Phosphorus Transport from Sediment)

  • 이정엽;강선홍
    • 상하수도학회지
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    • 제13권2호
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    • pp.89-94
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    • 1999
  • In this study small glass columns with 2.5cm inner diameter and 24.5cm length were used as many as the sample numbers to study the effects of initial pH, temperature, dissolved oxygen concentration, and sediment depth on the release of phosphorus from lake sediment. No phosphorus release occurred at $10^{\circ}C$ with all pHs, and release rate at $25^{\circ}C$ was higher than that at $35^{\circ}C$ with pH 4 and reverse trends were observed at pH 7 and 10. Under all conditions, DO concentrations were decreased and equilibrium was obtained after 4-8 days when phosphorus release started and the Do concentrations were less than 1 mg/l. Sediment depth had little effect on phosphorus release rate. It was found that relation between released SRP(Soluble Reactive Phosphorus) concentration and time was zero order reaction and reaction rate coefficients were obtained. The amount of phosphorus release from lake sediment can be predicted by considering these k values.

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