• 제목/요약/키워드: stable degree

검색결과 608건 처리시간 0.037초

Production and Characterization of Acid-stable Pectin Lyase from Bacillus sp. PN33

  • Kim, Jong-Chon;Kim, Hwa-Young;Choi, Yong-Jin
    • Journal of Microbiology and Biotechnology
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    • 제8권4호
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    • pp.353-360
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    • 1998
  • A bacterial strain PN33 producing large amounts of extracellular pectin lyase (PNL, EC 4.2.2.10) was isolated from soil. The isolated bacterium was identified as a strain of Bacillus sp. Production of PNL by the strain was induced only by pectins, with a higher degree of esterification, which had been added to the culture medium as a sole carbon source. The optimal medium for PNL production was determined to consist of 10 g pectin, 2 g yeast extract, 4 g $K_2HPO_4{\cdot}3H_2O$, 0.6 g $MgSO_4$, and 0.11 g $CaCl_2$ per liter (pH 7.0). The PNL activity in the culture supernatant reached the highest level of 132 mU/ml after 32 h cultivation at $37^{\circ}C$ in the optimal medium. The PNL produced was purified to homogeneity by ammonium sulfate fractionation (50~80%), and cation exchange and size exclusion chromatographies. The molecular mass of the enzyme was estimated to be approximately 52 kDa by SDS-PAGE. Almost the same mass was determined by nondenaturing PAGE, indicating that the functional enzyme had a monomeric structure. As expected, the PNL exhibited higher activities on the highly esterified pectins whereas it gave no detectable activity on polygalacturonic acid. The enzyme showed the highest activity at the acidic pH of 6.0, exceptional for a bacterial PNL. Maximum activity was measured at $40^{\circ}C$, although the stability f the purified enzyme was poor at this temperature. alcium (1 mM) was found to activate the PNL activity by $50\%$, and also remarkably increased the thermal stability f the enzyme. Phenylmethylsulfonylfluoride (PMSF) and iethylpyrocarbonate (DEPC) inhibited the PNL activity lmost completely at the concentration of 5 mM. This result ndicates that some serine and histidine residues of the nzyme may play an essential role for catalytic function of he enzyme.

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키토산 올리고사카라이드 및 그 유도체의 제조와 특성에 관한 연구 (Studies on the Preparation and the Properties of Chitosan Oligosaccharide and its Derivatives)

  • 하병조;김준오;이옥섭
    • 대한화장품학회지
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    • 제23권2호
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    • pp.48-62
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    • 1997
  • 천연 고분자인 키토산의 1차 아민기를 아질산나트륨염에 의해 환원 말단에 알데히드기를 갖는 키토산 올리고사카라이드를 얻었으며, 이를 수소화붕소산나트륨으로 환원하여 수산기로 전환하였다. 얻어진 키토산 올리고사카라이드의 평균 중합도는 겔투과 크로마토그라피를 통해 약 2로 나타났으며, 키토산에 비해 친수성 용매에 대한 용해성이 매우 높게 나타났다. 보습효과를 글리세린과 비교 측정한 결과 키토산 올리고사카라이드는 어느 정도 수분을 보유할 수 있는 능력은 있으나 글리세린에 비하여 약한 것으로 나타났다. 피부의 섬유아세포 증식 실험결과1$\times$10-3 ~ 1$\times$10-4%농도에서 115 ~ 125%의 세포증식 효과를 보였다. 키토산 올리고사카라이드에 아실클로라이드를 반응시켜 얻은 N, N-디아실, O-아실 키토산 올리고사카라이드는 액정을 형성하였으며, 높은 결정성을 보였다. 또한 유동파라핀, 에스테르형 오일 성분 등에 대한 용해성이 우수하여 화장품용 유성성분으로서의 가능성을 나타내었다.

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Simplified Cubature Kalman Filter for Reducing the Computational Burden and Its Application to the Shipboard INS Transfer Alignment

  • Cho, Seong Yun;Ju, Ho Jin;Park, Chan Gook;Cho, Hyeonjin;Hwang, Junho
    • Journal of Positioning, Navigation, and Timing
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    • 제6권4호
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    • pp.167-179
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    • 2017
  • In this paper, a simplified Cubature Kalman Filter (SCKF) is proposed to reduce the computation load of CKF, which is then used as a filter for transfer alignment of shipboard INS. CKF is an approximate Bayesian filter that can be applied to non-linear systems. When an initial estimation error is large, convergence characteristic of the CKF is more stable than that of the Extended Kalman Filter (EKF), and the reliability of the filter operation is more ensured than that of the Unscented Kalman Filter (UKF). However, when a system degree is large, the computation amount of CKF is also increased significantly, becoming a burden on real-time implementation in embedded systems. A simplified CKF is proposed to address this problem. This filter is applied to shipboard inertial navigation system (INS) transfer alignment. In the filter design for transfer alignment, measurement type and measurement update rate should be determined first, and if an application target is a ship, lever-arm problem, flexure of the hull, and asynchronous time problem between Master Inertial Navigation System (MINS) and Slave Inertial Navigation System (SINS) should be taken into consideration. In this paper, a transfer alignment filter based on SCKF is designed by considering these problems, and its performance is validated based on simulations.

임상실습에 대한 간호학생의 태도 : Q 방법론 적용 (Attitudes of Nursing Students to Clinical Education : Q methodological Approach)

  • 박송자
    • 대한간호학회지
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    • 제23권4호
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    • pp.544-554
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    • 1993
  • The study was designed to identify the attitude of nursing students to clinical education through Q-methodology. A C sample was developed through a review of the literature and interviews. Twenty - seven statements made up the finalized Q- sample. This was out of an initial 143 statements developed through consultation with eight professors. The P sample consisted of 25 nursing students in S Health Junior College.0 statements were written on seperate cards and were given to the 25 subjects to sort according to degree of agreement or disagreement. The Q-sorts by each subject were coded and analyzed with QUANL PC Program. The analysis discovered three major attitudes, namely “amicable adaptation” 〈type 1), “Nightingale social service” (type 2), and “realistic occupation pursuit” (type 3). The correlation was .465 between type 1 and type 2, .293 between type 1 and type 3, and .273 between type 2 and type 3. The characteristics of each type were as follows ; Type 1 (amicable adaptation) They satisfied in interpersonal relationships in the clinical setting. They would not dream of becoming Nightingale, but thought of nursing care affirmatively and performed their works faithfully and adapted themselves to the new circumstances easily, Fourteen subjects were classified as type 1. Type 2 (Nightingale: social service) They often dreamed as a child that they would be Nightingale with a white uniform and think that nursing is a gift from heaven. They have an aptitude for nursing care by nature and selected nursing science them-selves. They give care to the sick with pleasure. Seven subjects were classified as type 2. Type 3 (realistic occupation pursuit) They were not satisfied with their nursing practice. First of all they want a stable job, therefore they selected nursing science. They had conflicts in clinical practice, but were responsible for nursing and studied hard. Four subjects were classified as type 3. Through the results of this study, the attitude of nursing students to clinical education could be classified into three types. Therefore it is suggested that clinical education would be more valuable, if it was planned according to an understanding of the attitudes of nursing students to clinical education.

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Prediction of shiver differentiation by the form alteration on the stable condition

  • Kim, Jeong-lae;Kim, Kyu-dong
    • International Journal of Internet, Broadcasting and Communication
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    • 제9권4호
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    • pp.8-13
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    • 2017
  • Movement technique is comprised of the movement status of the circulation differentiation rate (CDR) and rotation differentiation rate (RDR) on the shiver movement form. Condition of the differentiation rate by the shiver movement form is to be modified the teetering movement system. As to fix the movement of signal on the material of body, we compared a shiver value of the circulation differentiation rate on the circulation state. The concept of rotation differentiation rate was identified the reference of rotation differentiation signal and rotation differentiation signal by the rotation state. For detecting a alteration of the CDR-RDR of the maximum and average in terms of the movement form, and shiver movement value that was a shiver value of the top alteration of the Top-ф$_{MAX-AVG}$ with $12.80{\pm}1.27units$, that was a shiver value of the peripheral alteration of the Per-ф$_{MAX-AVG}$ with $4.38{\pm}1.15units$, that was a shiver value of the limbus alteration of the Lim-ф$_{MAX-AVG}$ with $1.65{\pm}0.25units$, that was a shiver value of the center alteration of the Cen-ф$_{MAX-AVG}$ with $0.25{\pm}0.01units$. The teetering movement will be to assess at the ability of the movement form for the control degree of differentiation rate on the CDR-RDR that was shown the circulation and rotation form by the differentiation rate system. Teetering differentiation system was modified of a form by the special movement and was included a shiver data of teetering movement rate.

파괴역학을 이용한 경화모래로 이루어진 사면의 해석 (Analysis of Steep Cuts and Slopes in Cemented Sand Using Fracture Mechanics)

  • Kim, Tae-Hoon;Kang, Kwon-Soo;Lee, Jong-Cheon
    • 한국지반공학회논문집
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    • 제19권6호
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    • pp.161-168
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    • 2003
  • 대부분의 자연상태의 사질토는 어느 정도 경화되어 있다. 경화의 정도는 흙의 체적변형 거동이나 강도에 중요한 영향을 준다. 경화된 사질토 지반의 중요한 특징은 사질토임에도 불구하고 굉장히 높이 서 있을 수 있다는 것이다. 많은 현장 관측이나 경화모래로 된 사면의 파괴 해석들은 기존의 사면해석방법이 적절하지 않다는 것을 보여준다. 이것은 단지 파괴면이 원호가 아니라는 점뿐만 아니라 파괴면에서의 전단응력이 실험으로부터 얻어진 전단강도보다 훨씬 작기 때문일 것이다. 이러한 사실은 파괴양상이 Mohr-Coulomb 전단파괴와 다르다는 것을 말한다. 이런 파괴는 파괴역학 개념과 이론으로 설명될지도 모른다. 이 논문에서는 파괴 역학 개념을 이용해서 경화모래로 이루어진 급경사 사면의 해석을 수행하였다. FEM 해석 결과는 파괴역학의 개념을 이용한 해석방법이 경화사질토로 이루어진 지반구조물의 설계나 안정해석에 훌륭한 대안임을 보여주고 있다.

α2,6-Sialyltransferase 과발현을 통한 인간형 시알산 부가 hCTLA4-Ig 생산 CHO 세포주 제작 (Engineering Human-like Sialylation in CHO Cells Producing hCTLA4-Ig by Overexpressing α2,6-Sialyltransferase)

  • 임진혁;차현명;박혜진;김하형;김동일
    • KSBB Journal
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    • 제32권3호
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    • pp.193-198
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    • 2017
  • Sialylation is important in producing therapeutic proteins such as antibody, cytokine and fusion protein. Thus, enhancement of sialylation is usually performed in CHO cell cultures. ${\alpha}2,6$-Sialyltransferase (ST), which plays a key role in the attachment of ${\alpha}2,6-sialic$ acid, is present in human cells but not in Chinese hamster ovary (CHO) cells. Overexpression of ${\alpha}2,6-ST$ can be used for enhancing the degree of sialylation and achieving human-like glycosylation. In this study, we constructed CHO cells producing human cytotoxic T-lymphocyte antigen4-immunoglobulin (hCTLA4-Ig) as well as ${\alpha}2,6-ST$. Transfected CHO cells were selected using G418 and stable cell line was established. Profiles of viable cell density and hCTLA4-Ig titer in an overexpressed cell line were similar to those of a wild-type cell line. It was confirmed that the total amount of sialic acid was increased and ${\alpha}2,6-sialic$ acid was attached to the terminal residues of N-glycan of hCTLA4-Ig by ESI-LC-MS. Compared to 100% of ${\alpha}2,3-sialic$ acid in wild type cells, 70.9% of total sialylated N-glycans were composed of ${\alpha}2,6-sialic$ acid in transfected cells. In conclusion, overexpression of ${\alpha}2,6-ST$ in CHO cells led to the increase of both the amount of total sialylated N-glycan and the content of ${\alpha}2,6-sialic$ acid, which is more resemble to human-like structure of glycosylation.

Ti/Au, Ti/Pd/Au 쇼트키 접촉의 열처리에 따른 GaAs MESFET의 전기적 특성 (Electrical characteristics of GaAs MESFET according to the heat treatment of Ti/Au and Ti/Pd/Au schottky contacts)

  • 남춘우
    • E2M - 전기 전자와 첨단 소재
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    • 제8권1호
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    • pp.56-63
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    • 1995
  • MESFETs of the Ti/Au and Ti/Pd/Au gate were fabricated on n-type GaAs. Interdiffusion at Schottky interfaces, Schottky contact properties, and MESFET characteristics with heat treatment were investigated. Ti of Ti/Au contact and Pd of Ti/Pd/Au contact acted as a barrier metal against interdiffusion of Au at >$220^{\circ}C$. Pd of Ti/Pd/Au contact acted as a barrier metal even at >$360^{\circ}C$, however, Ti of Ti/Au contact promoted interdiffusion of Au instead of role of barrier metal. As the heat treatment temperature increases, in the case of both contact, saturated drain current and pinch off voltage decreased, open channel resistance increased, and degree of parameter variation in Ti/Au gate was higher than in Ti/Pd/Au gate at >$360^{\circ}C$ Schottky barrier height of Ti/Au and Ti/Pd/Au contacts was 0.69eV and 0.68eV in the as-deposited state, respectively, and Fermi level was pinned in the vicinity of 1/2Eg. As the heat treatment temperature increases, barrier height of Ti/Pd/Au contact increased, however, decreased at >$360^{\circ}C$ in the case of Ti/Au contact. Ideality factor of Ti/Au contact was nearly constant regardless of heat treatment, however, increased at >$360^{\circ}C$ in the case of Ti/Au contact. From the results above, Ti/Pd/Au was stable gate metal than Ti/Au.

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Treatment of Nonsyndromic Craniosynostosis Using Multi-Split Osteotomy and Rigid Fixation with Absorbable Plates

  • Nam, Su Bong;Nam, Kyeong Wook;Lee, Jae Woo;Song, Kyeong Ho;Bae, Yong Chan
    • 대한두개안면성형외과학회지
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    • 제17권4호
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    • pp.211-217
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    • 2016
  • Background: Nonsyndromic craniosynostosis is a relatively common craniofacial anomaly and various techniques were introduced to achieve its operative goals. Authors found that by using smaller bone fragments than that used in conventional cranioplasty, sufficiently rigid bone union and effective regeneration capacity could be achieved with better postoperative outcome, only if their stable fixation was ensured. Methods: Through bicoronal incisional approach, involved synostotic cranial bone together with its surrounding areas were removed. The resected bone flap was split into as many pieces as possible. The extent of this 'multi-split osteotomy' depends on the degree of dysmorphology, expectative volume increment after surgery and probable dead space caused by bony gap between bone segments. Rigid interosseous fixation was performed with variable types of absorbable plate and screw. In all cases, the pre-operational three-dimensional computed tomography (3D CT) was checked and brain CT was taken immediately after the surgery. Also about 12 months after the operation, 3D CT was checked again to see postoperative morphology improvement, bone union, regeneration and intracranial volume change. Results: The bony gaps seen in the immediate postoperative brain CT were all improved as seen in the 3D CT after 12 months from the surgery. No small bone fragment resorption was observed. Brain volume increase was found to be made gradually, leaving no case of remaining epidural dead space. Conclusion: We conclude that it is meaningful in presenting a new possibility to be applied to not only nonsyndromic craniosynostosis but also other reconstructive cranial vault surgeries.

환경정보시스템을 이용한 산사태 발생위험 예측도 작성: 경상북도를 중심으로 (Development of Landslide Hazard Map Using Environmental Information System: Case on the Gyeongsangbuk-do Province)

  • 배민기;정규원;박상준
    • 한국환경과학회지
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    • 제18권11호
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    • pp.1189-1197
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    • 2009
  • The purpose of this research was develop tailored landslide hazard assessment table (LHAT) in Gyeongsangbuk-do Province and propose building strategies on environmental information system to estimate landslide hazard area according to LHAT. To accomplish this purpose, this research investigated factors occurring landslide at 172 landslide occurred sites in 23 city and county of Gyeongsangbuk-do Province and analyzed what factors effected landslide occurrence quantity using the multiple statistics of quantification method(I). The results of analysis, factors affecting landslide occurrence quantity were shown in order of slope position, slope length, bedrock, aspect, forest age, slope form and slope. And results of the development of LHAT for predict mapping of landslide-susceptible area in Gyeongsangbuk-do Province, total score range was divided that 107 under is stable area(IV class), 107~176 is area with little susceptibility to landslide(III class), 177~246 is area with moderate susceptibility to landslide(II class), above 247 area with severe susceptibility to landslide(I class). According to LHAT, this research built landslide attribute database and made 7 digital theme maps at mountainous area located in Goryeong Gun, Seongju-Gun, and Kimcheon-City. The results of prediction on degree of landslide hazard using environmental information system, area with little susceptibility to landslide(III class) occupied 65.56% and severe susceptibility to landslide(I class) occupied 0.51%.