• 제목, 요약, 키워드: Immobilization

검색결과 1,332건 처리시간 0.034초

EFFECTS OF XYLAZINE (ALPHA 2-ADRENERGIC AGONIST) ON THE STRESS RESPONSE TO IMMOBILIZATION AND HEAT IN RATS

  • Fayed, A.H.;Zakaria, A.D.;Hedaya, S.A.;El-Ashmawy, I.M.
    • 아세아태평양축산학회지
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    • v.7 no.3
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    • pp.397-400
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    • 1994
  • The effect of xylazine administration on plasma cortisol, prolactin, glucose and packed cell volume (PCV) responses to immobilization and heat stress was investigated. Immobilization of rats for 2 hours by ligation of the fore and hind legs strongly caused approximately two-fold increase in plasma cortisol and prolactin levels. Plasma glucose and PCV were not significantly changed. Pretreatment of immobilized rats with xylazine (20 mg/kg body weight i.m.) resulted in approximately 20% reduction in both plasma cortisol and prolactin concentrations. A marked hyperglycemia and increase in the PCV value was observed. On the other hand, rats exposed to acute heat stress ($40^{\circ}C$, and 60% relative humidity) for 2 hours, also developed two fold increase in both plasma cortisol and prolactin concentrations and the pretreatment with xylazine caused a 20% reduction in the levels of both hormones. Plasma glucose level was not significantly changed in heat stressed rats but it was markedly increased after pretreatment with xylazine. PCV was significantly incrcased under heat stress and pretreatment with xylazine induced a pronounced elevation in this value. It was suggested that stimulation of cortisol and prolactin secretion in response to immobilization or heat stress can be partially reduced by an alpha 2-adrenergic agonist.

나이트로벤젠다이아조늄 양이온의 화학 및 전기화학 반응을 이용한 실리콘 표면상으로의 단백질 고정 (Immobilization of Proteins on Silicon Surfaces Using Chemical and Electrochemical Reactions of Nitrobenzenediazonium Cations)

  • 김규원;하크 알-몬술;강현주
    • 전기화학회지
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    • v.13 no.1
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    • pp.70-74
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    • 2010
  • 전기화학 반응을 이용한 실리콘 표면상으로의 단백질 고정을 연구하였다. 이를 위해 Nitrobenzendiazonium(NiBD) 양이온을 화학적 환원반응을 통해 수식하고 수식된 실리콘 표면을 전기화학적으로 다시 환원시켜 나이트로 기능기를 일차아민 기능기로 활성화하여 단백질 고정에 이용하였다. 활성화 된 표면에 금 나노입자를 고정하여 일차 아민 생성을 확인하였다. 또한 이 방법을 응용하여 실리콘 나노선 어레이 중 선택된 나노선 만을 활성화하고 단백질을 선택적으로 고정하는 연구를 수행하였다. 이 연구를 통하여 NiBD 양이온의 화학 및 전기화학 반응이 실리콘 나노선 표면으로 단백질의 선택적 고정화에 유용하게 사용될 수 있음을 보였다.

Simultaneous and Sequential Co-Immobilization of Glucose Oxidase and Catalase onto Florisil

  • Gul, Ozyilmaz;Tukel, S. Seyhan
    • Journal of Microbiology and Biotechnology
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    • v.17 no.6
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    • pp.960-967
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    • 2007
  • The co-immobilization of Aspergillus niger glucose oxidase (GOD) with bovine liver catalase (CAT) onto florisil (magnesium silicate-based porous carrier) was investigated to improve the catalytic efficiency of GOD against $H_2O2$ inactivation. The effect of the amount of bound CAT on the GOD activity was also studied for 12 different initial combinations of GOD and CAT, using simultaneous and sequential coupling. The sequentially co-immobilized GOD-CAT showed a higher efficiency than the simultaneously co-immobilized GOD-CAT in terms of the GOD activity and economic costs. The highest activity was shown by the sequentially co-immobilized GOD-CAT when the initial amounts of GOD and CAT were 10 mg and 5 mg per gram of carrier. The optimum pH, buffer concentration, and temperature for GOD activity for the same co-immobilized GOD-CAT sample were then determined as pH 6.5, 50 mM, and $30^{\circ}C$, respectively. When compared with the individually immobilized GOD, the catalytic activity of the co-immobilized GOD-CAT was 70% higher, plus the reusability was more than two-fold. The storage stability of the co-immobilized GOD-CAT was also found to be higher than that of the free form at both $5^{\circ}C\;and\;25^{\circ}C$. The increased GOD activity and reusability resulting from the co-immobilization process may have been due to CAT protecting GOD from inactivation by $H_2O2$ and supplying additional $O_2$ to the reaction system.

공유결합으로 다공성 막에 고정화된 효소에 의한 이산화탄소 포집 (Carbon Dioxide Sequestration of Enzyme Covalently Immobilized on Porous Membrane)

  • 박진원
    • KSBB Journal
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    • v.28 no.4
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    • pp.225-229
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    • 2013
  • Bovine Carbonic anhydrase (BCA) was immobilized on a submicro-porous membrane through covalent immobilization. The immobilization was conducted on the porous membrane surface with the treatment of polyethyleneimine, glutaraldehyde, and the anhydrase, in sequence. The immobilization was confirmed using X-ray photon spectrometer. The pH values of carbon-dioxide saturated solution with buffer were monitored with respect to time to calculate the catalytic activities of hydration of carbon-dioxide for free and immobilized CA. The catalytic rate constant values for free CA, immobilized CA on polystyrene nanoparticles, and immobilized CA on a porous cellulose acetate membrane were 0.79, 0.67, and 0.56 $s^{-1}$, respectively. Reusability was studied up to 10 cycles of $CO_2$ sequestration. The activity for the CA immobilized on the membrane was kept to 95% after 10 cycles, and comparable to the CA on the nanoparticles. The stabilities for heat and storage were also investigated for the three cases. The results suggested that the CA immobilized the membrane had the least loss rate of the activity compared to the others. From this study, the porous membrane was feasible as a carrier for the CA immobilization in hydration and sequestration of carbon-dioxide.

우울증 유발 생쥐에서 온담탕가오약(溫膽湯加烏藥)의 항우울 효과 (Anti-Depressive Effects of OnDam-Tang with Addition of Linderae Radix (ODT-L) after Chronic Immobilization Stress in C57BL/6 Mice)

  • 이은희;정인철
    • 동의생리병리학회지
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    • v.28 no.4
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    • pp.403-410
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    • 2014
  • The purpose of this study was to examine the anti-depressive effects of OnDam-Tang with addition of Linderae Radix (ODT-L) on the animal model of depression induced by chronic immobilization stress. Depression model was made by chronic immobilization stress for 2 hours for 21 days. And we performed forced swimming test, analysis of the neurotransmitter and immunohistochemical staining, measured expression levels of serotonin in the brain. ODT-L has decreased immobilization time in forced swimming test. ODT-L has increased amount of melatonin in the brain. ODT-L has increased expression levels of serotonin in the brain. ODT-L prevented damage in the hippocampal region. ODT-L has reduced the expression level of CRF receptors in in hippocampus region. These results suggest that ODT-L may have anti-depressive effects on depression.

Ginsenoside Rb1 Modulates Level of Monoamine Neurotransmitters in Mice Frontal Cortex and Cerebellum in Response to Immobilization Stress

  • Lee, Sang-Hee;Hur, Jin-Young;Lee, Eun-Joo H.;Kim, Sun-Yeou
    • Biomolecules & Therapeutics
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    • v.20 no.5
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    • pp.482-486
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    • 2012
  • Cerebral monoamines play important roles as neurotransmitters that are associated with various stressful stimuli. Some components such as ginsenosides (triterpenoidal glycosides derived from the Ginseng Radix) may interact with monoamine systems. The aim of this study was to determine whether ginsenoside Rb1 can modulate levels of the monoamines such as dihydroxyphenylalanine (DOPA), dopamine (DA), norepinephrine (NE), epinephrine (EP), 3,4-dihydroxyphenylacetic acid (DOPAC), 5-hydorxytryptamine (5-HT), 5-hydroxindole-3-acetic acid (5-HIAA), and 5-hydroxytryptophan (5-HTP) in mice frontal cortex and cerebellum in response to immobilization stress. Mice were treated with ginsenoside Rb1 (10 mg/kg, oral) before a single 30 min immobilization stress. Acute immobilization stress resulted in elevation of monoamine levels in frontal cortex and cerebellum. Pretreatment with ginsenoside Rb1 attenuated the stress-induced changes in the levels of monoamines in each region. The present findings showed the anti-stress potential of ginsenoside Rb1 in relation to regulation effects on the cerebral monoaminergic systems. Therefore, the ginsenoside Rb1 may be a useful candidate for treating several brain symptoms related with stress.

Immobilization of α-amylase from Exiguobacterium sp. DAU5 on Chitosan and Chitosan-carbon Bead: Its Properties

  • Fang, Shujun;Chang, Jie;Lee, Yong-Suk;Hwang, Eun-Jung;Heo, Jae Bok;Choi, Yong-Lark
    • Journal of Applied Biological Chemistry
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    • v.59 no.1
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    • pp.75-81
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    • 2016
  • Glutaraldehyde was used as a cross-linking agent for immobilization of purified ${\alpha}$-amylase from Exiguobacterium sp. DAU5. Befitting concentration of glutaradehyde and cross-linking time is the key to preparation of cross-linking chitosan beads. Based on optimized immobilization condition for ${\alpha}$-amylase, an overall yield of 56% with specific activity of 2,240 U/g on chitosan beads and 58% with specific activity of 2,320 U/g on chitosan-carbon beads was obtained. The optimal temperature and pH of each immobilized enzyme activity were $50^{\circ}C$ and 50 mM glycine-NaOH buffer pH 8.5, respectively. Those retained more than 75 and 90% of its maximal enzyme activity at pH 7.0-9.5 and after incubation at $50^{\circ}C$ for 1 h, respectively. In addition, the immobilization product showed higher organic-solvent tolerance than free enzymes. The mode of hydrolyzing soluble starch revealed that the ${\alpha}$-amylase possessed high hydrolyzing activity. These results indicate that chitosan is good support and has broad application prospects of enzyme immobilization.

Immobilization of oxidative enzymes onto Cu-activated zeolite to catalyze 4-chlorophenol decomposition

  • Zol, Muhamad Najmi Bin;Shuhaimi, Muhammad Firdaus Bin;Yu, Jimin;Lim, Yejee;Choe, Jae Wan;Bae, Sungjun;Kim, Han S.
    • Membrane Water Treatment
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    • v.11 no.3
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    • pp.195-200
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    • 2020
  • In this study, a biocatalyst composite was prepared by immobilizing oxidoreductases onto Cu-activated zeolite to facilitate biochemical decomposition of 4-chlorophenol (4-CP). 4-CP monooxygenase (CphC-I) was cloned from a 4-CP degrading bacterium, Pseudarthrobacter chlorophenolicus A6, and then overexpressed and purified. Type X zeolite was synthesized from non-magnetic coal fly ash using acetic acid treatment, and its surfaces were coated with copper ions via impregnation (Cu-zeolite). Then, the recombinant oxidative and reductive enzymes were immobilized onto Cu-zeolite. The enzymes were effectively immobilized onto the Cu-zeolite (79% of immobilization yield). The retained catalytic activity of CphC-I after immobilization was 0.3423 U/g-Cu-zeolite, which was 63.3% of the value of free enzymes. The results of this study suggest that copper can be used as an effective enzyme immobilization binder because it provides favorable metalhistidine binding between the enzyme and Cu-zeolite.

Immobilization-induced rhabdomyolysis patients with peripheral neuropathy: clinical, laboratory and imaging findings

  • Seok, Jung Im;Lee, In Hee;Ahn, Ki Sung;Kang, Gun Woo;Lee, Je Wan;Kwak, Sanggyu
    • Annals of Clinical Neurophysiology
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    • v.22 no.1
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    • pp.19-23
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    • 2020
  • Background: Peripheral nerve injury rarely occurs in patients with rhabdomyolysis. Based on our experience and previous reports, we consider prolonged immobilization a risk factor for the development of peripheral neuropathy in rhabdomyolysis patients. Methods: This study analyzed 28 patients with rhabdomyolysis due to prolonged immobilization. We analyzed their demographic and laboratory data, clinical and imaging findings, and outcomes, and compared these factors between patients with and without neuropathy. Results: Seven of the 28 patients had peripheral neuropathy, including sciatic neuropathy or lumbosacral plexopathy. Compared to those without neuropathy, the patients with neuropathy were younger (p = 0.02), had higher peak creatine kinase (CK) levels (p = 0.02), had higher muscle uptake in bone scans (p = 0.03), and more frequently exhibited abnormal muscle findings in computed tomography (CT) (p = 0.004). Conclusions: Patients with prolonged immobilization-induced rhabdomyolysis and neuropathy had higher CK levels, increased uptake on bone scans, and more-frequent abnormal muscles on CT than those without neuropathy. These findings indicate that peripheral neuropathy is more likely to develop in patients with severe muscle injury.

Remediation of Groundwater contaminated MTBE using Micellar immobilization

  • 백기태;양지원
    • 한국지하수토양환경학회:학술대회논문집
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    • pp.330-333
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    • 2002
  • Immobilization isotherms for methyl tort-buty1 ether (MTBE) in sodium dodecy1 sulfate(SDS) and cetylpyridinium chloride (CPC) were investigated for application to micellar enhanced remediation. Headspace solid-phase microextraction was used to analyze immobilization isotherms. Maximum partitioning coefficients of MTBE were 48 L/mol and 9 L/mol for SDS and CPC, respectively, The values decreased gradually as the MTBE mole fraction in the micelles increased.

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