• 제목/요약/키워드: pal

검색결과 1,093건 처리시간 0.029초

Influence of Controlled- and Uncontrolled-pH Operations on Recombinant Phenylalanine Ammonia Lyase Production in Escherichia coli

  • Cui, Jian Dong;Zhao, Gui Xia;Zhang, Ya Nan;Jia, Shi Ru
    • Food Science and Biotechnology
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    • 제18권4호
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    • pp.954-958
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    • 2009
  • Effects of controlled- and uncontrolled-pH operations on phenylalanine ammonia lyase (PAL) production by a recombinant Escherichia coli strain were investigated at uncontrolled-pH ($pH_{UC}$) and controlled-pH ($pH_C$) of 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, and 8.5 in bioreactor systems. The results showed that the recombinant PAL activity was improved significantly by controlled pH strategy. Among the $pH_C$ operations, the highest PAL activities were obtained under $pH_C$ 7.5 strategy where cell mass ($OD_{600\;nm}$) and PAL activity was 1.3 and 1.8 fold higher than those of $pH_{UC}$, respectively. The maximum PAL activity reached 123 U/g. The $pH_C$ 7.5 strategy made recombinant plasmid more stable and therefore allowed easier expression of PAL recombinant plasmid, which increased PAL production. It was indicated that the new approach (controlled-pH strategy) obtained in this work possessed a high potential for the industrial production of PAL, especially in the biosynthesis of L-phenylalanine.

간호교육에서 동료학습의 효과와 전략에 대한 체계적 문헌고찰 (Strategies of Peer-Assisted Learning and Their Effectiveness in Nursing Education: A Systematic Review)

  • 박인희;홍정민;신수진
    • 의학교육논단
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    • 제18권2호
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    • pp.106-113
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    • 2016
  • The purpose of this study is to identify factors associated with effective peer-assisted learning (PAL) for nursing students. This review examined studies on PAL in nursing education. The literature was searched using terms including 'nursing & peer assisted learning,' 'nursing & peer learning,' and 'nursing & peer teaching.' Potentially relevant research on PAL was identified, and 12 studies were determined to meet the inclusion criteria. This review includes five qualitative, three mixed-methods, and three experimental studies published on the topic. In the studies reviewed, practicum classes were found to use PAL the most. Students of the same age were most commonly the subjects of PAL, as indicated in six papers. PAL has been suggested to affect participants' knowledge, self-efficacy, confidence, and anxiety. The findings indicate that interactions between peers promote learning and lead to mutually positive responses, which provide opportunities for self-development. Finally, students' learning outcomes improve and their confidence in their knowledge and skills increases as they experience the role of student nurse. These findings indicate that PAL can be utilized as an efficient learning method in nursing education programs. However, effective strategies for using PAL to achieve learning objectives and maximize learning outcomes are needed.

Purification and Characterization of Anabaena flos-aquae Phenylalanine Ammonia-Lyase as a Novel Approach for Myristicin Biotransformation

  • Arafa, Asmaa M.;Abdel-Ghany, Afaf E.;El-Dahmy, Samih I.;Abdelaziz, Sahar;El-Ayouty, Yassin;El-Sayed, Ashraf S.A.
    • Journal of Microbiology and Biotechnology
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    • 제30권4호
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    • pp.622-632
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    • 2020
  • Phenylalanine ammonia-lyase (PAL) catalyzes the reversible deamination of phenylalanine to cinnamic acid and ammonia. Algae have been considered as biofactories for PAL production, however, biochemical characterization of PAL and its potency for myristicin biotransformation into MMDA (3-methoxy-4, 5-methylenedioxyamphetamine) has not been studied yet. Thus, PAL from Anabaena flos-aquae and Spirulina platensis has been purified, comparatively characterized and its affinity to transform myristicin was assessed. The specific activity of purified PAL from S. platensis (73.9 μmol/mg/min) and A. flos-aquae (30.5 μmol/mg/min) was increased by about 2.9 and 2.4 folds by gel-filtration comparing to their corresponding crude enzymes. Under denaturing-PAGE, a single proteineous band with a molecular mass of 64 kDa appeared for A. flos-aquae and S. platensis PAL. The biochemical properties of the purified PAL from both algal isolates were determined comparatively. The optimum temperature of S. platensis and A. flos-aquae PAL for forward or reverse activity was reported at 30℃, while the optimum pH for PAL enzyme isolated from A. flos-aquae was 8.9 for forward and reverse activities, and S. platensis PAL had maximum activities at pH 8.9 and 8 for forward and reverse reactions, respectively. Luckily, the purified PALs have the affinity to hydroaminate the myristicin to MMDA successfully in one step. Furthermore, a successful method for synthesis of MMDA from myristicin in two steps was also established. Gas chromatography-mass spectrometry (GC-MS) analysis was conducted to track the product formation.

황제내경영추(黃帝內經靈樞)에서 살펴본 팔회혈(八會穴)의 의의(意義)와 형성체계(形成體系)에 대한 연구(硏究) (The Study of Meaning and Formation System of Pal Hyue Hyul through Hwangjaenaekyong)

  • 이봉효;문진영
    • Journal of Acupuncture Research
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    • 제22권6호
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    • pp.101-109
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    • 2005
  • Objectives : Pal Hyue Hyul has been mentioned in $Nanky{\hat{o}}ng$ firstly and is a representitive acupoint of 8 parts of biological function of human body. The aim of this study is to finding out the process of formation of Pal Hyue Hyul. Methods : In this study we investigated and summarized all literetures from $Hwangjaenaeky{\hat{o}}ng$ to the today's papers which refer to Pal Hyue Hyul, and then basing on it, suggested our opinion about the correlation. Results & Conclusion : The results and conclusions obtained are as follow: 1. Pal Hyue Hyul is based on the Sahae theory of $Y{\hat{o}}ngchu$ and was formed in 45nan of $Nanky{\hat{o}}ng$. 2. Although Pal Hyue Hyul has been mentioned in $Nanky{\hat{o}}ng$ firstly, but because even $Nanky{\hat{o}}ng$ shows the quickening of Pal Hyue Hyul theory, the birth of Pal Hyue Hyul was necessary from the viewpoint of studing ambience. 3. About the reason for formation to 8 types, we think that all the biological functions of human body were represented as 8. 4. Pal Hyue theory had been suplemented and completed by annotations of successive medical men, for example the arguement about Golhyue, Suhyue. And the reason for the extent from the heat disease of the first phase to the associated disease is that it has been useful in the clinical treatment. 5. Because about whether Suhyue is Ch'imgol or $J{\hat{o}}lgol$, whether $J{\hat{o}}lgol$ is Yangbo(GB38) or $Hy{\hat{o}}njong(GB39)$, whether Golhyue is Teacu'u(GV14) or $Taej{{\hat{o}}}(BL11)$ there in no agreement of opinion among the successive medical men, much more study is necessary.

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Effects of zinc bearing palygorskite supplementation on the growth performance, hepatic mineral content, and antioxidant status of broilers at early age

  • Yang, Weili;Chen, Yueping;Cheng, Yefei;Wen, Chao;Zhou, Yanmin
    • Asian-Australasian Journal of Animal Sciences
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    • 제30권7호
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    • pp.1006-1012
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    • 2017
  • Objective: This study was conducted to investigate effects of zinc (Zn) bearing palygorskite (ZnPal) supplementation on growth performance, hepatic mineral content, and antioxidant status of broilers at early age. Methods: A total of 240 1-day-old Arbor Acres broiler chicks were allocated into 5 treatments with 6 replicates of 8 chicks each. Birds in 5 treatments were fed a basal diet supplemented with 0 (Control group; Analyzed Zn content: 81 mg/kg), 20, 40, 60, and 80 mg/kg Zn as ZnPal for 21 days, respectively. Blood, liver and intestinal mucosa were collected at 21 days of age. Results: Treatments did not affect growth performance of broilers during the 21-day study (p>0.05). The contents of hepatic Zn and magnesium (Mg) were linearly increased (p<0.001) by ZnPal supplementation. ZnPal inclusion linearly (p = 0.007) reduced malondialdehyde (MDA) concentration in serum. The activity of total superoxide dismutase (T-SOD) in liver increased linearly (p = 0.001) with concentration of ZnPal in diet. ZnPal inclusion linearly (p = 0.036) and quadratically (p = 0.005) increased T-SOD activity, and linearly (p = 0.012) increased copper/zinc superoxide dismutase (Cu/Zn SOD) activity in jejunal mucosa. The maximum responses of hepatic and jejunal antioxidant enzymes activities (T-SOD and Cu/Zn SOD) were found when supplementing the basal diet with 60 mg/kg Zn as ZnPal. Furthermore, ZnPal supplementation quadratically (p = 0.001) increased Cu/Zn SOD activity in ileal mucosa, and its maximum activity was observed in the diet supplemented with 20 mg/kg Zn as ZnPal. Conclusion: ZnPal supplementation did not alter growth performance of broilers. Dietary ZnPal inclusion could increase concentrations of hepatic trace minerals (Zn and Mg) and inhibit lipid peroxidation by reducing serum MDA accumulation, with the optimal dosage of Zn from ZnPal being 80 mg/kg diet (analyzed Zn content in the diet: 165 mg/kg), and 60 mg/kg Zn as ZnPal (analyzed Zn content in the diet: 148 mg/kg) was the optimum dosage for broilers to achieve maximum antioxidant enzyme activities.

750kW gearless형 풍력발전 시스템용 모의시험 장치의 개발 (Development of a Simulator for 750 kW Gearless Wind Turbine)

  • 권세진;손윤규;서재학;이월우;장성덕;오종석;황진수;박가우;권오정
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 하계학술대회 논문집 B
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    • pp.1190-1192
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    • 2004
  • 풍력을 이용한 풍력발전기의 전력변환 시스템을 개발하기 위해서는 바람특성을 정확히 분석하고 이를 대치할 수 있는 모의시험 장치가 필수적이다. 모의시험 장치는 풍향, 풍속 등의 인자들을 입력받아 회전 블레이드의 토오크를 전동기가 대신해서 발전기에 공급하게 된다. 본 논문에서는 풍력발전 모의시험 장치를 이용해서 현재 개발 중인 750kW gearless형 풍력발전 시스템의 인버터 특성과 고효율의 전력변환 설계를 위해 시험용 지그에서 시험한 결과를 보이고자 한다.

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Dermal Stability and In Vitro Skin Permeation of Collagen Pentapeptides (KTTKS and palmitoyl-KTTKS)

  • Choi, Yun Lim;Park, Eun Ji;Kim, Eunje;Na, Dong Hee;Shin, Young-Hee
    • Biomolecules & Therapeutics
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    • 제22권4호
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    • pp.321-327
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    • 2014
  • Collagen pentapeptide (Lys-Thr-Thr-Lys-Ser, KTTKS) and its palmitoylated derivative (pal-KTTKS) have received a great deal of attention as cosmeceutical ingredients for their anti-wrinkle effects. The objective of this study was to evaluate stability and permeability of KTTKS and pal-KTTKS in hairless mouse skin. In this study, a liquid chromatography-tandem mass spectrometric method was developed for the quantification of pal-KTTKS, and used for stability and permeability studies. Stability studies were performed using skin extracts and homogenates. Both KTTKS and pal-KTTKS were rapidly degraded, but pal-KTTKS was more stable than KTTKS. When protease inhibitors were added, the stability of both compounds (KTTKS and pal-KTTKS) improved significantly. In the skin permeation study, neither KTTKS nor pal-KTTKS was detected in the receptor solution, which indicates that neither compound could permeate through the full-thickness hairless mouse skin in the experimental conditions of this study. While KTTKS was not detected in any of the skin layers (the stratum corneum, epidermis, and dermis), pal-KTTKS was observed in all skin layers: $4.2{\pm}0.7{\mu}g/cm^2$ in the stratum corneum, $2.8{\pm}0.5{\mu}g/cm^2$ in the epidermis, and $0.3{\pm}0.1{\mu}g/cm^2$ in the dermis. In conclusion, this study indicated that pal-KTTKS had greater stability and permeability than that of un-modified KTTKS, and may be a useful anti-wrinkle and anti-aging cosmeceutical agent.