• 자원리싸이클링
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• 제30권1호
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• pp.44-52
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• 2021

본 연구에서는 알칼리성 침전제 종류 따라 제조되는 수산화리튬 결정화 정도 확인을 위해 폐리튬이차전지로부터 회수된 황산리튬을 원료로 사용하여 수산화리튬 제조 거동을 확인하였다. 황산리튬의 리튬염 전구체에 포함되어 있는 불순물 제거 및 높은 수산화리튬 합성효율을 위해 2차 침전법인 Double replacement reaction(DRR) 공정을 사용하였으며, 결정성 높은 수산화리튬 제조를 위하여 알칼리성 침전제(KOH, Ca(OH)2, Ba(OH)2)를 포함하여 전구체 몰비 ([Li]/[OH]) 및 합성온도 조건을 변수로 두어 실험을 진행하였다. 반응 후 생성된 불순물 제거를 위해 2차 고/액 분리를 실시하였고 불순물이 제거된 수산화리튬 수용액은 증발을 통해 수분 제거하여 분말을 수득하였다. 최종적으로 수득한 분말의 결정성 평가 및 제조 거동을 확인하였다.

• 대한의생명과학회지
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• 제23권3호
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• pp.230-237
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• 2017

Changes in the activity of alkaline phosphatase (ALP) isoenzymes and isoforms in human serum have a major diagnostic value, therefore the regulation of ALP activities is a valuable target for therapeutic interventions. To assess the pharmacological activity of retinoids, i.e., all-trans retinoic acid and 13-cis retinoic acid, their tissue-specific inhibitory effect on human serum ALP activity was elucidated by chemical inhibition methods, heat-sensitive inactivation, and wheat-germ lectin precipitation test. Retinoids showed significant inhibition of the total ALP activity in human serum at a concentration of 5 mM. All-trans retinoic acid (5 mM) and 13-cis retinoic acid (5 mM) inhibited ALP activities by up to 12% and 15%, respectively, compared to that by guanidine hydrochloride (200 mM). L-phenylalanine (100 mM) and urea (30 mM) had no further inhibitory effect on ALP activities in human serum pretreated with retinoids (5 mM). Retinoids significantly inhibited ALP activities by up to 20% compared with that of tetramisole (30 mM). The ALP activities in retinoid-pretreated serum remained unchanged after the heat inactivation process. These results suggest that retinoids are inhibitors of the intestinal ALP isoenzyme. Remarkably, retinoids revealed potent inhibitory activities against ALP in wheat-germ lectin precipitant serum, indicating that they also function as inhibitors of the bone ALP isoform. The results show that retinoids inhibit the specific tissue-derived human serum ALP activities, moreover, the inhibitory effect of retinoids against bone ALP activity suggests their clinical utility as monitoring and prevention of metastasis of bone cancer.

• 대한수의학회지
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• 제47권2호
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• pp.157-162
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• 2007

Lactic acid bacteria (LAB) has been regarded as a useful microorganism and tried to manipulate plasmid DNA for increasing the usefulness. Although several methods have been developed to isolate plasmid DNA from Escherichia coli (E. coli), these methods were not sufficient to apply to LAB with exception of O'Sullivan's lysis method. So, we evaluated plasmid DNA extraction from LAB using general E. coli preparation methods and tried to improve the extraction yield and DNA purity by modifying O'Sullivan's alkaline lysis method. To improve the extraction yield, salt and carrier were added to precipitant and those were incubated at $-70{^{\circ}C}$. Only incubation at $-70{^{\circ}C}$ was the effective method of those modifications. Purity of plasmid DNA was improved by two times of each centrifugation and phenol/chloroform extraction. However, DNA was damaged by twice extraction with phenol/chloroform. Also, exclusion of ethidium bromide showed negative effect to purity. Additionally, it was recommended that improvement of the extraction yield may be due to centrifugation at high speed for more time and to dissolving complete DNA pellet before addition of 7.5 M ammonium acetate. Extraction using this modification produced higher quality of plasmid DNA.