• Title/Summary/Keyword: Independent suspension

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The Effect of Acidic pH on the Spectral Properties of Bacteriorhodopsin (산성 pH가 박테리오로돕신의 분광학적 성질에 미치는 효과)

  • Quae Chae
    • Journal of the Korean Chemical Society
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    • v.23 no.5
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    • pp.320-324
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    • 1979
  • Purple membrane from Halobacterium halobium was incorporated into 7.5% polyacrylamide gels. Absorption and circular dichroic spectra of purple membrane incorporated with gels were obtained at various pH. The spectra of these gels measured at pH 7.0 were essentially identical with those obtained in the aqueous suspension of purple membrane. Acid titration of the gels showed the transition to a form absorbing at 605nm $(bR_{605}^{acid}$) at pH 2.6, and to a second form at 565nm $(bR_{565}^{acid})$ at pH 0.8. Dark-adapted gels showed an isosbestic point for each transition whereas light-adapted gels did not. Visible CD spectra of $bR_{570}^{LA},\;bR_{305}^{acid}\;and\;bR_{565}^{acid}$ all showed the typical bilobed pattern. CD spectra measured at UV wavelength region were also independent of the variation of pH in terms of molar ellipticity and spectral shape. The protonated species $bR_{605}^{acid}$ may be one of the intermediates formed during the normal photochemical cycle of purple membrane. Most probably, the species $bR_{605}^{acid}$ is considered to be $O^{640}$ in the cycle.

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Effect of Cadmium Chloride on the Immune Responses in Balb/c Mouse (카드뮴투여가 Balb/c 마우스의 면역반응에 미치는 영향)

  • 염정호;강현철;고대하
    • Journal of Environmental Health Sciences
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    • v.21 no.3
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    • pp.16-22
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    • 1995
  • This study was designed to investigate the antibody production to sheep red blood cells(SRBC) and proliferation of mitogen-stimulated spleen cells in Balb/c mice which received cadmium chloride. The mice were divided into three independent groups which were one control and two experimental groups by the cadmium treatment or not. No specific treatment was done for the control group. One of two experimental groups, which is called 'pre-treatment group' in this paper, was subcutaneously injected with low dose of cadmium chloride(0.5 mg/kg/day) for 5 consecutive days before the primary SRBC immunization. The other called 'non-pretreatment group' was only pretreated with normal saline. Both experimental groups were intraperitoneally injected with high dose of cadmium chloride(5 mg/kg) 8 hours before the primary immunization. Mice were intraperitoneally immunized twice with 2% SRBC suspension containing $10^8$ cells. The results obtained were as follows, 1. The PFG responses to SRBC were significantly increased in two experimental groups, cadmium pretreatment and non-pretreatment compared with that of control group(p<0.05). 2. The total antibody titers to SRBC in cadmium treated groups were similar to that of control group, but titers of IgG antibody were significantly elevated(p<0.01). 3. The proliferation response of spleen lymphocytes to various mitogens was suppressed in proportion to the concentration of cadmium and the degree of cadmium accumulation in liver was increased in the cadmium treated groups. These results suggest that cadmium chloride could affect on mouse immune response, especially its cell mediated immune response could be decreased while its humoral immune response could be increased, which may not be influenced by the administration methods or pretreatment of cadmium to mouse.

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Development of the All-Wheel-Steering Algorithm using Dynamic Analysis of the Bi-modal Vehicle (저상굴절차량의 주행해석을 이용한 전차륜 조향 알고리즘 개발)

  • Jeon, Yong-Ho;Park, Tae-Won;Lee, Soo-Ho;Kim, Duk-Gie;Moon, Kyung-Ho
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.1
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    • pp.144-151
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    • 2008
  • The bi-modal vehicle is composed of two car-bodies and three axles. Each axle of the vehicle has an independent suspension and all wheels are steerable. Since the bi-modal vehicle has longer wheelbase than most urban buses, the All-Wheel-Steering(AWS) system is adapted for to ensure safe driving and proper turning radius on a curved road. This paper proposes an AWS control algorithm for stable driving of bi-modal vehicle. Steering angles and directions of each axle of bi-modal vehicle changed according to the driving environment and steering modes. In the case that front and rear axles should be steered in opposite directions is a negative mode, and the other case that the axles should be steered in the same direction is a positive mode. For example, in the positive mode, front and real axles are steered in the same direction, while in the negative mode, they are steered in the opposite direction. A multibody model of the vehicle is used to verify the performance of the steering algorithm and simulation results of 2WS are compared with those of AWS under the same condition.

The Effects of Vibration and Side-lying Hip Abduction on Pain, Disability, Strength and Balance in Individuals with Low Back Pain (진동을 동반한 옆교각 운동이 요통 성인의 통증, 기능장애, 근력, 균형에 미치는 영향)

  • Gwon, Ae-Jeong;Kim, Suhn-Yeop
    • Journal of the Korean Society of Physical Medicine
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    • v.11 no.4
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    • pp.127-137
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    • 2016
  • PURPOSE: This study aimed to compare the effects of side-lying hip abduction exercise with and without vibration on pain, disability, strength and balance in individuals with low back pain. METHODS: 30 participants enrolled in this study were randomly assigned to an experimental group (EG, n=15) for side-lying hip abduction with vibration and a control group (CG, n=15) for side-lying hip abduction without vibration. Both groups were treated 3 times per week for 4 weeks. Pain (Numeric Rating Scale), disability (Korean Oswestry Disability Index), hip abductor muscle strength, and static balance were measured in both groups before and after the program. Results were analyzed using paired t-test for comparing the difference within the group and independent t-test for comparing the difference between two groups. RESULTS: Compared to the CG, the EG showed significantly greater reductions in pain and disability (p<.05). There was a significant difference in all balance categories of both the painful and non-painful sides within the EG (p<.05). Balance showed a significant decrease except the envelope area (ENV) on the non-painful side within the CG (p<.05). There was a significant increase in all balance categories except ENV of non-painful side between the two groups (p<.05). Balance increased on both the painful and non-painful sides in the EG. Balance improved on the painful side in the CG, but significantly decreased on the non-painful side (p<.05). CONCLUSION: Side-lying hip abduction exercise with vibration is considered an effective treatment for pain, disability and balance in individuals with low back pain.

An Implicit Integration Method for Joint Coordinate Subsystem Synthesis Method (조인트 좌표계를 이용한 부분시스템 합성방법의 내재적 적분기법)

  • Jo, Jun-Youn;Kim, Myoung-Ho;Kim, Sung-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.4
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    • pp.437-442
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    • 2012
  • To analyze a multibody system, this paper proposes an implicit numerical integration method for joint coordinates subsystem synthesis method. To verify the proposed method, a multibody model for an unmanned robot vehicle, which consists of six identical independent suspension systems, is developed. The symbolic method is applied to compute the system Jacobian matrix for the implicit integration method. The proposed method is also verified by performing rough terrain run-over simulation in comparison with the conventional implicit integration method. In addition, to evaluate the efficiency of the proposed method, the CPU time obtained by using this method is compared with that obtained by using the conventional implicit method.

The necessity for the Korean Dental Hygiene Education Accreditation System (한국 치위생학 교육 평가인증제도의 필요성)

  • Kim, Ji-Youn;Kim, Young-Sook;Jung, Soon-Hee;Shin, Je-Won
    • Journal of Korean society of Dental Hygiene
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    • v.14 no.6
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    • pp.789-794
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    • 2014
  • The increasing cross-border mobility of dental school or dental hygiene students, educators, practitioners, programs and providers takes challenges for existing national quality assurance and accreditation frameworks and bodies, as well as for the systems for recognizing foreign qualifications. The new dental hygiene accreditation system was introduced to encourage the improvement of dental hygiene programs, to ensure the quality of education and, most of all, to establish an internationally compatible system of evaluation and accreditation. The accreditation procedure takes 1 year to complete. The result of the accreditation is released after evaluation via self-study report, site visit, preliminary draft report, responses from the institution and the results from the conciliation and review committees. The result from the accreditation procedure is either 'accreditation' or 'no accreditation'. Accredited schools receive one of several statuses following the evaluation. These are next general review, interim report and interim visit or suspension. Dental healthcare quality is not improved instantaneously, but instead gradually through continuous communication within the dental field. For this accreditation system to be successful, the following are essential: the accreditation agency should adopt hygiene education accreditation; it needs to become financially independent and managed efficiently; the autonomy and regulations surrounding the system need to be balanced; the professionalism of the system is ensured; and the dental field which includes not only dental program, but also hygiene program, needs to play an active role in the operation of the system.

Development of Controlled Release Oral Drug Delivery System by Membrane-Coating Method-I - Preparation and pharmaceutical evaluation of controlled release acetaminophen tablets-

  • Shim, Chang-Koo;Kim, Ki-Man;Kim, Young-Il;Kim, Chong-Kook
    • Archives of Pharmacal Research
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    • v.13 no.2
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    • pp.151-160
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    • 1990
  • In order to develop a controlled-release oral drug delivery system (DDS) which sustains the plasma acetaminophen (AAP) concentration for a certain period of time, microporous membrane-coated tablets were prepared and evaluated in vitro. Firstly, highly water-soluble core tablet of AAP were prepared with various formulations by wet granulation and compression technique. Then the core tablets were coated with polyvinychloride (PVC) in which micronized sucrose particles were dispersed. Effect of formula compositions of core tablets and coating suspensions on the pharmaceutical characteristics such as drug release kinetics and membrane stability of the coated tablets was investigated in vitro. AAP was released from the coated tablets as a zero-order rate in a pH-independent manner. This independency of AAP release to pH change from 1.2 to 7.2 is favorable for the controlled oral drug delivery, since it will produce a constant drug release in the stomach and intestine regardless of the pH change in the GI tract. Drug release could be extended upto 10 h according to the coating condition. The release rate could be controlled by changing the formula compositions of the core tablets and coating suspensions, coat weight per each tablet, and especially PVC/sucrose ratio and particle size of the sucrose in the coating suspension. The coated tablets prepared in this study had a fairly good pharmaceutical characteristics in vitro, however, overall evaluation of the coated tablet should await in vivo absorption study in man.

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Instability of Anthocyanin Accumulation in Vitis vinifera L. var. Gamay Freaux Suspension Cultures

  • Qu Junge;Zhang Wei;Yu Xingju;Jin Meifang
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.10 no.2
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    • pp.155-161
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    • 2005
  • The inherent instability of metabolite production in plant cell culture-based bioprocessing is a major problem hindering its commercialization. To understand the extent and causes of this instability, this study was aimed at understanding the variability of anthocyanin accumulation during long-term subcultures, as well as within subculture batches, in Vitis vinifera cell cultures. Therefore, four cell line suspensions of Vitis vinifera L. var. Gamay Freaux, A, B, C and D, originated from the same callus by cell-aggregate cloning, were established with starting anthocyanin contents of $2.73\;\pm\;0.15,\;1.45\;\pm\;0.04,\;0.7\;\pm\;0.024\;and\;0.27\;\pm\;0.04$CV (Color Value)/g-FCW (fresh cell weight), respectively. During weekly subculturing of 33 batches over 8 months, the anthocyanin biosynthetic capacity was gradually lost at various rates, for all four cell lines, regardless of the significant difference in the starting anthocyanin content. Contrary to this general trend, a significant fluctuation in the anthocyanin content was observed, but with an irregular cyclic pattern. The variabilities in the anthocyanin content between the subcultures for the 33 batches, as represented by the variation coefficient (VC), were 58, 57, 54, and $84\%$ for V. vinifera cell lines A, B, C and D, respectively. Within one subculture, the VCs from 12 replicate flasks for each of 12 independent subcultures were averaged, and found to be $9.7\%$, ranging from 4 to $17\%$. High- and low-producing cell lines, VV05 and VV06, with 1.8-fold differences in their basal anthocyanin contents, exhibited different inducibilities to L-phenylalanine feeding, methyl jasmonate and light irradiation. The low-producing cell line showed greater potential in enhanced the anthocyanin production.

Participation and Influencing Factors in the Decision-Making of Life-Sustaining Treatment: A Focus on Deceased Patients with Hematologic Neoplasms

  • Jae Eun Jang;Jeong Moon Ryu;Min Hee Heo;Do Eun Kwon;Ji Yeon Seo;Dong Yeon Kim
    • Journal of Hospice and Palliative Care
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    • v.26 no.2
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    • pp.69-79
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    • 2023
  • Purpose: This study aimed to investigate the involvement of patients who died from hematologic neoplasms in the decision-making process surrounding the withdrawal of life-sustaining treatment (LST). Methods: A total of 255 patients diagnosed with hematologic neoplasms who ultimately died following decisions related to LST during their end-of-life period at a university hospital were included in the study. Data were retrospectively obtained from electronic medical records and analyzed utilizing the chi-square test, independent t-test, and logistic regression. Results: In total, 42.0% of patients participated in the decision-making process regarding LST for their hematologic neoplasms, while 58.0% of decisions were made with family involvement. Among these patients, 65.1% died in general wards and 34.9% in intensive care units (ICUs) as a result of decisions such as the suspension of LST. The period from the LST decision to death was longer when the decision was made by the patient (average, 27.15 days) than when it was made by the family (average, 7.48 days). Most decisions were made by doctors and family members in the ICU, where only 20.6% of patients exercised their right to make decisions regarding LST, a rate considerably lower than 79.4% observed in general wards. Decisions to withhold or withdraw LST were more commonly made by patients themselves than by their families. Conclusion: The key to discussing the decision to suspend hospice care and LST is respecting the patient's self-determination. If a patient is lucid prior to admission to the ICU, considerations about suspending LST should involve the patient input.

Preparation of Polystyrene Beads by Suspension Polymerization with Hydrophobic Silica as a Stabilizer in Aqueous Solution (소수성 실리카를 안정제로 이용하는 수용액 상에서의 현탁중합법에 의한 폴리스티렌 입자 합성)

  • Park, Moon-Soo
    • Polymer(Korea)
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    • v.30 no.6
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    • pp.498-504
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    • 2006
  • A suspension polymerization of styrene In aqueous phase was employed to study if polystyrene particles ranging from 1 to $20{\mu}m$ can be produced. Hydrophobic silica was selected as a stabilizer and azo-bisisobutyronitrile (AIBN) as an initiator. Polymerization reaction was carried out at a selected temperature in the range of $65{\sim}95^{\circ}C$. Stabilizer concentration was varied from 0.17 to 3.33 wt% compared to the water while the concentration of the initiator was raised from 0.13 to 6.0 wt% compared to the monomer. Dispersion of hydrophobic silica into the water phase was achieved by precise control of pH. Optimum dispersion of silica was obtained at pH 10. Average particle diameter decreased with increasing amounts of stabilizer concentration initially, exhibiting the minimum average diameter at 1.67 wt% of stabilizer concentration, after which it started to Increase. It is speculated that an excessive presence of stabilizer encouraged a secondary reaction in the reaction medium, which led to particle agglomeration, and as a result an increase in average particle diameter. Molecular weight was found to be independent of stabilizer concentration between 0.13 and 1.00 wt% whereas, it increased when stabilizer concentration exceeded 1.67 wt%. Variation of molecular weight was probably caused by the reduced activity and efficiency of initiator due to the high concentration of silica, and the secondary reaction in the reaction medium, as well. An increase in the Initiator concentration and/or reaction temperature resulted in an increase in both reaction rate and particle diameter. Consequently, we have confirmed that spherical polystyrene particles with $1{\sim}20{\mu}m$ in diameter can be prepared by careful selection of the concentration of stabilizer, initiator, pH and reaction temperature.