• 한국토양비료학회지
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• 제29권2호
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• pp.113-123
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• 1996

국내산(國內産)과 수입(輸入) 중국산(中國産) 입상(粒狀) 용성인비(熔成燐肥)의 물리화학적 특성을 비교하기 위해 pH의 경시적 변화, 입도분포(粒度分布), 수중 및 토양중 붕괴도(崩壞度), 토양중 경도(硬度), 제품의 화학성분(化學成分) 함량(含量) 분석(分析), 수중 및 토양중 구용성(枸溶性) 인산(燐酸) 용출율(溶出率) 등(等)을 검토한 결과를 요약(要約)하면 다음과 같다. 1. pH의 경시적(傾時的) 변화(變化)는 중문통(中文統)(농암갈색(濃暗褐色) 토양(土壤))이 평대통(坪垈統)(흑색(黑色) 토양(土壤))보다, 수입(輸入) 중국산(中國産) 제품(製品)이 풍농비료 제품 보다, 중문통(中文統)에 용성인비(熔成燐肥)를 다량(多量) 시용(施用)한 것이 소량 시용한 것 보다 pH의 변화(變化)가 컸었다. 2. 국내산(國內産) 용성인비(熔成燐肥)는 수입 중국산 용성인비에 비하여 pH, 석회(石灰), 알카리분 및 가용성(可溶性) 규산함량(珪酸含量)이 낮았으나 인산(燐酸) 전량(全量), 구용성(枸溶性) 인산(燐酸), 고토(苦土)(가용성(可溶性) 구용성(枸溶性)) 및 구용성(枸溶性) 망간은 약간 높거나 서로 비슷하였다. 3. 입도(粒度)의 크기는 수입(輸入) 중국산(中國産) 제품(製品)이 가장 크고 그 다음이 경기화학(京畿化學) 제품(製品)이며 풍농비료(豊農肥料)의 제품(製品)은 비교적 입자가 작았다. 4. 수중(水中) 및 토양중(土壤中) 붕괴도(崩壞度)는 초기(初期)에는 풍농비료 제품과 경기화학 제품이 낮았으나 후기(後期)에는 경기화학 제품>수입 중국산 제품>풍농비료 제품의 순으로 붕괴도가 낮았다. 5. 토양중(土壤中) 경도(硬度)는 경기화학(京畿化學) 제품(製品)이 가장 단단하였고 그 다음이 풍농비료(豊農肥料) 제품(製品)이며 수입(輸入) 중국산(中國産) 제품(製品)은 경도계로 측정할 수 없을 정도로 약하였다. 6. 구용성(枸溶性) 인산(燐酸) 용출율(溶出率)은 초기에는 경기화학(京畿化學) 제품(製品)이 가장 높았고 풍농비료(豊農肥料) 제품(製品)은 가장 낮았으며, 용출 50일에는 3제품(製品) 모두 90% 이상 용출되었고 용출 70일 이후는 제품간(製品間) 차이가 거의 없었다. 7. 토양중(土壤中) 구용성(枸溶性) 인산(燐酸) 용출율(溶出率)은 풍농비료(豊農肥料) 제품(製品)이 가장 높았고 수입(輸入) 중국산(中國産) 제품(製品)이 가장 낮았으며 용출일 100일에도 60%를 넘지 못하였다.

• 약학회지
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• 제42권3호
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• pp.265-274
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• 1998

In order to attain a sustained release at targeted organs in a prolonged time which can reduce the side effects and maximize the therapeutic effect, aclarubicin (ACL) was entrap ped into liposomes of different lipid compositions using Microfluidizer, and dry liposomes were prepared by lyophilization. The dry aclarubicin-entrapped liposomes were evaluated in terms of mean particle size and size distribution, entrapment efficiency and in vitro drug release profile. The Entrapment efficiency of liposome, when the concentration of aclarubicin and lipid were 0.5 to 1.0mg/ml and $200{\mu}mol$/ml, respectively, was over 80% using Microfluidizer, in contrast to 70% of entrapment efficiency using hand-shaking method. Mean particle size and size distribution of aclarubicin-entrapped liposomes of various lipid compositions did not change considerably by the freeze drying. The range of particle size was between 80 and 200nm. Among aclarubicin-entrapped liposomes, ACL-liposome of PC/DPPC/CH0L/TA displayed the most significant sustained release. The addition of DPPC appeared to be favorable for the control of release. In general, aclarubicin entrapped in liposomes was less stable than free aclarubicin either in pH 7.4 phosphate buffer or in human plasma. Formulation I($t_{1/2}$, 20.3 hr) devoid of lipid additive was the most unstable in the phosphate-buffer solution while formulation II($t_{1/2}$, 40.7 hr) with cardiolipin was the most stable. Half lives of aclarubicin-entrapped liposomes in human plasma were 43.2, 50.7, 35.9 and 35.3 hr for formulation I. II, III and IV, respectively, in contrast to 57.8 hr for free aclarubicin.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권4호
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• pp.36-43
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• 2012

Various methods are used to remediate soil contaminated with heavy metals or petroleum. In recent years, harsh physical and chemical remediation methods are being used to increase remediation efficiency, however, such processes could affect soil properties and degrade the ecological functions of the soil. Effects of soil washing, thermal desorption, and land farming, which are the most frequently used remediation methods, on the physicochemical properties of remediated soil were investigated in this study. For soils smaller than 2 mm, the soil texture were changed from sandy clay loam to sandy loam because of the decrease in the clay content after soil washing, and from loamy sand to sandy loam because of the decrease in the sand content and increase in silt content during thermal desorption, however, the soil texture remained unchanged after land farming process. The water-holding capacity, organic matter content, and total nitrogen concentration of the tested soil decreased after soil washing. A change in soil color and an increase in the available phosphate concentration were observed after thermal desorption. Exchangeable cations, total nitrogen, and available phosphate concentration were found to decrease after land farming; these components were probably used by microorganisms during as well as after the land farming process because microbial processes remain active even after land farming. A study of these changes can provide information useful for the reuse of remediated soil. However, it is insufficient to assess only soil physicochemical properties from the viewpoint of the reuse of remediated soil. Potential risks and ecological functions of remediated soil should also be considered to realize sustainable soil use.

• 대한치과보철학회지
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• 제38권2호
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• pp.169-177
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• 2000

The purpose of this study was to compare the retention of complete cast crown over amalgam ores, composite resin cores, and cast gold cores when cemented with three different luting agents. Eighteen core specimens each of amalgam(Bestaloy, Dong Myung, Seoul, Korea), composite resin (Z100, 3M Dental product, st. Paul, Minn) and type IV gold alloy (Ba-4, Heesung Engelhard Corp., Korea) were made in a customized milling stainless steel die. A wax pattern with a loop attached to occlusal surface was made for each core and a type II gold alloy casting was fabricated. The castings which had clinically acceptable marginal fit were used as test samples. The following luting cements were used to cement cast crowns on each core material : (1) zinc phosphate cement (Confi-dental Products Co., USA) (2) glass-ionomer cement (Fuji Plus, GC Industrial Corp., Tokyo, Japan) (3) resin cement (Panavia 21, Kuraray Co., USA). All cements were mixed according to manufacturers' instructions. A static load of 5kg was then applied for 10 minutes on the crowns. All specimens were stored in saline solution for 24 hours at $37^{\circ}C$ and thermocycled for 500 cycles. After storage and cycling, the tensile bond strengths were measured by using a universal testing machine (Instron Corp., Canton, Mass.) at a crosshead speed of 0.5mm/min. The results were as follows 1. The retentive strength of resin cement was the highest of alt three types of cement for resin core (p<0.05). 2. There was no statistical difference among the retentive strengths of three cements for amalgam core (p>0.05). 3. The retentive strength of resin cement was higher than that of zinc phosphate for cast core, but there was no difference between the retentive strength of glass ionomer cement and those of rein and zinc phosphate cement. 4. The retentive strength of the zinc phosphate cement for amalgam core was the highest of all type of cores.

• 자원리싸이클링
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• 제32권3호
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• pp.9-17
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• 2023

폐리튬인산철 전지의 양극재로부터 리튬을 효율적으로 회수하기 위하여 활발하게 연구 중이며, 이는 리튬 자원의 지역 편재성 및 가격 변동성을 해소하고 환경오염 문제를 해결할 수 있다. 폐리튬인산철 전지로부터 리튬을 침출 및 회수하기 위하여 동형치환 침출 공정을 사용하였다. 상대적으로 저렴한 염화철 에칭액을 침출제로 사용하여 LFP의 Fe²⁺를 동형 치환하여 리튬을 침출하였다. 또한 추가적인 첨가제 및 추출제 없이 염화철 에칭액만을 사용하였으며, 염화철 에칭액을 LFP 이론적 몰 비 대비 0.7배, 1.0배, 1.3배, 그리고 1.6배로 하여 리튬의 침출율을 비교하였다. LFP 몰 비 대비 1.3배의 조건에서 약 98%로 가장 높은 리튬 침출율을 보였고 이후 침출액은 NaOH를 투입하여 pH 조절을 통하여 철을 제거하였다. 철이 제거된 용액으로부터 탄산리튬을 합성하였고, 그 분말 특성을 확인하였다.

• 청정기술
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• 제30권1호
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• pp.28-36
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• 2024

전기차의 수요가 증가함에 따라 리튬이온전지의 시장 또한 급증하고 있다. 리튬이온전지의 배터리 수명은 제한되어 있으며, 수명을 다한 배터리의 교체 필연적이므로 폐리튬이온전지 배터리가 발생하게 된다. 이에 리튬이온전지 중 폐리튬인산철(LiFePO₄, 이하 LFP라고 함) 양극재 분말에서부터 리튬은 선택적으로 선침출하고 인산철(FePO₄) 분말을 회수하였다. 회수된 인산철 분말은 탄산나트륨(Na₂CO₃) 분말과 혼합하여 열처리하여 그 결정상을 확인하였다. 열처리 온도를 변수로 하였고, 이후 증류수를 이용하여 수침출 후 각 성분의 침출률 및 분말 특성을 비교하였다. 본 연구에서 리튬은 약 100% 침출률을 보였고 800 ℃에서 열처리한 분말의 경우 인이 약 99% 침출되었으며, 침출 잔사는 Fe₂O₃ 단일 결정상으로 확인되었다. 따라서 본 연구에서는 폐LFP 분말로부터 리튬, 인 그리고 철 성분을 개별적으로 분리 및 회수할 수 있었다.

• Journal of Pharmaceutical Investigation
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• 제40권4호
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• pp.251-254
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• 2010

The formation of acylated peptide impurities in poly(lactide-co-glycolide) (PLGA) formulations is one of the major challenges to the development of successful sustained-release product. Octreotide, synthetic analogue of somatostatin, has been identified to be acylated in PLGA microsphere formulations. The purpose of this study was to investigate the pH effect on the formation of acylated octreotides by PLGA. In the incubation with PLGA in 0.1 M phosphate buffer at pH 7.4, approximately 98% of octreotide adsorbed to PLGA through 14 days and 66.3% of acylated octreotides were produced after 42 days, whereas the interaction of octreotide with PLGA was significantly inhibited in the incubation at pH 4, in which the acylated octreotides were observed to be 9.2% after 42 days. In the interaction study at pH 4.1-7.4, the production of acylated octreotides was demonstrated to be dependent on environmental pH. Below pH 5.0, the acylation of octreotide was significantly inhibited. This study indicates that the pH is the major factor for the formation of acylated octreotide in PLGA formulations.

• 미생물학회지
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• 제24권1호
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• pp.46-50
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• 1986

일산화탄소를 유일한 탄소 및 에너지원으로 이용하여 성장한 Acinetobacter sp. 1의 일산화탄소 산화를 전자전달계를 조사하였다. 이 세균은 a, b, c, 그리고 o형의 사이토크롬을 소유하고 있었고, UQ 10은 이 세균의 생리적인 전자수용제로 작용할 수 없음이 밝혀졌다. 이 세균에 존재하는 사이토크롬들 중에서 b와 o는 일산화탄소 산화와 연관되어 있으나 a와 c는 관계가 없었으며, NAD(P)도 이 세균의 일산화탄소 산화와 무관한 것으로 밝혀졌다.

• Asian-Australasian Journal of Animal Sciences
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• 제23권6호
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• pp.700-707
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• 2010

Effects of protease-resistant antimicrobial substances (PRA) produced by Lactobacillus plantarum and Leuconostoc citreum on rumen methanogenesis were examined using the in vitro continuous methane quantification system. Four different strains of lactic acid bacteria, i) Lactococcus lactis ATCC19435 (Control, non-antibacterial substances), ii) Lactococcus lactis NCIMB702054 (Nisin-Z), iii) Lactobacillus plantarum TUA1490L (PRA-1), and iv) Leuconostoc citreum JCM9698 (PRA-2) were individually cultured in GYEKP medium. An 80 ml aliquot of each supernatant was inoculated into phosphate-buffered rumen fluid. PRA-1 remarkably decreased cumulative methane production, though propionate, butyrate and ammonia N decreased. For PRA-2, there were no effects on $CH_4$ and $CO_2$ production and fermentation characteristics in mixed rumen cultures. The results suggested that PRA-1 reduced the number of methanogens or inhibited utilization of hydrogen in rumen fermentation.

• Archives of Pharmacal Research
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• 제27권10호
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• pp.1009-1015
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• 2004

Quantitative Structure-Resolution Relationship (QSRR) using the Comparative Molecular Field Analysis (CoMFA) software was applied to predict the chromatographic behaviors of chiral drugs with an amine moiety on the chiral cellobiohydrolase (CBH) columns. As a result of the Quantitative CoMFA-Resolution Relationship study, using the partial least square method, prediction of the behavior of drugs with amine moiety upon chiral separation became possible from their three dimensional molecular structures. When a mixed mobile phase of 10 mM aqueous phosphate buffer (pH 7.0) - isopropanol (95 : 5) was employed, the best Quantitative CoMFA-Resolution Relationship, derived from the study, provided a cross-validated $q^2$ = 0.933, a normal $r^2$ = 0.995, while the best Quantitative CoMFA-Separation Factor Relationship, also derived from the study, yielded a cross-validated $q^2$ = 0.939, a normal $r^2$ = 0.991. When all of these results are considered, this QSRR-CoMFA analysis appears to be a very useful tool for the preliminary prediction on the chromatographic behaviors of drugs with an amine moiety inside chiral CBH columns.