• Title/Summary/Keyword: contact effect

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An Experimental Study on the Analysis of the Interventricular Pressure Waveform in the Moving-Actuator type Total Artificial Heart (이동작동기식 완전 이식형 인공 심장의 심실간 공간 압력 파형 해석에 관한 실험적 연구)

  • 조영호;최원우
    • Journal of Biomedical Engineering Research
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    • v.18 no.1
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    • pp.25-36
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    • 1997
  • To regulate cardiac output of the Total Artificial Heart(TAH) physiologically, the hemodynamic information must be toed back to the controller. So far, our group has developed an automatic cardiac output control algorithm using the motor current waveform, It is, however difficult to detect the preload level such as a filling status of ventricular inflow and the variation of atrial pressures within normal physiologic range(0-15 mmHg) by analyzing the motor current which simultaneously reflects the afterload effect. On the other hin4 the interventricular volume pressure(IVP) which is not influenced by arterload but by preload is a good information source for the estimation of preload states. In order to find the relationship between preload and IVP waveform, we set up the artificial heart system on the Donovan type mock circulatory system and measured the IVP waveform, right and left atrial pressures, inflow and outflow waveforms and the signals represented the information of moving actuator's position. We shows the feasibility of estimating the hemodynamic changes of inflow by using IVP waveform. fife found that the negative peak value of IVP waveform is linearly related to atrial pressures. And we also found that we could use the time to reach the negative peak in IVP waveform, the time to open outflow valve, the area enclosed IVP waveform as unfu parameters to estimate blood filling volume of diastole ventricle. The suggested method has advantages of avoiding thrombogenesis, bacterial niche formation and increasing longterm reliability of sensor by avoiding direct contact to blood.

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Evidence to Support the Therapeutic Potential of Bacteriophage Kpn5 in Burn Wound Infection Caused by Klebsiella pneumoniae in BALB/c Mice

  • Kumar, Seema;Harja, Kusum;Chhibber, Sanjay
    • Journal of Microbiology and Biotechnology
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    • v.20 no.5
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    • pp.935-941
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    • 2010
  • The emergence of antibiotic-resistant bacterial strains is one of the most critical problems of modern medicine. Bacteriophages have been suggested as an alternative therapeutic agent for such bacterial infections. In the present study, we examined the therapeutic potential of phage Kpn5 in the treatment of Klebsiella pneumoniae B5055-induced burn wound infection in a mouse model. An experimental model of contact burn wound infection was established in mice employing K. pneumoniae B5055 to assess the efficacy of phage Kpn5 in vivo. Survival and stability of phage Kpn5 were evaluated in mice and the maximum phage count in various organs was obtained at 6 h and persisted until 36 h. The Kpn5 phage was found to be effective in the treatment of Klebsiella-induced burn wound infection in mice when phage was administered immediately after bacterial challange. Even when treatment was delayed up to 18 h post infection, when all animals were moribund, approximately 26.66% of the mice could be rescued by a single injection of this phage preparation. The ability of this phage to protect bacteremic mice was demonstrated to be due to the functional capabilities of the phage and not due to a nonspecific immune effect. The levels of pro-inflammatory cytokines (IL-$1{\beta}$ and TNF-${\alpha}$) and anti-inflammatory cytokines (IL-10) were significantly lower in sera and lungs of phage-treated mice than phage untreated control mice. The results of the present study bring out the potential of bacteriophage therapy as an alternate preventive approach to treat K. pneumoniae B5055-induced burn wound infections. This approach not only helps in the clearance of bacteria from the host but also protects against the ensuing inflammatory damage due to the exaggerated response seen in any infectious process.

A Study on the Spatial types and characteristics of Ramp (램프(Ramp)의 공간적 유형과 특성에 관한 연구)

  • Lee, Sun-Young;Lee, Hyoung-Geun
    • Korean Institute of Interior Design Journal
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    • v.16 no.3 s.62
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    • pp.38-45
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    • 2007
  • In the architectural space of modem age, expanding to the vertical and horizontal direction for the interaction between space and space is becoming an indispensable factor, and in this expansion, ramps are being positioned as one of the important factors. With an increased use of ramps, they show a variety of changes in types, functions and even concepts. The space where modem ramps are used exhibits a phenomenon that accommodates and expands many functions as well as the confined function of moving people, and is widening the scope of recognition on the functions of ramp. In addition, this phenomenon can be seen as an architectural reflection on the complexation trend of the modem society, the components comprising a ramp contact the body of experiencers closely and thus have a direct effect on their behavior or feeling, and owing to this, it is a space where new functions and meaning are highly likely to be derived. In this study, spaces where ramps are used stay away from an element of uniform vertical movement but have an independent environment within the entire space, thereby being used as a space dominating the nature of the building, not a subsidiary element of it. In this study, therefore, it could be known that spaces in which ramps are used are different in their meaning according to the patterns, not as an element of uniform vertical movement. In addition, these conclusions are the results by analyzing the patterns of ramps taking place in modem spaces and are thought to be helpful in understanding spaces where ramps are used.

Washing for Debittering of Brewers Yeast Slurry (맥주효모 슬러리의 쓴맛을 제거하기 위한 세척)

  • Kim, Jae-Sik
    • Korean Journal of Food Science and Technology
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    • v.33 no.2
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    • pp.205-208
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    • 2001
  • The bitterness of brewers yeast slurry decreased by washing with mild caustic soda solution followed by washing with 0.85% (w/v) NaCl solution The higher concentration of caustic soda was, the lower the bitterness unit(BU) of washed yeast slurry was. The lethal rate of yeast cells increased. When the concentration of caustic soda solution increased from 0.05%(w/v) to 0.25%(w/v), the BU of brewers yeast slurry was decreased from 45 to 3, but yeast cells viability decreased from 93% to 0%. The optimum washing conditions of brewers yeast slurry were as follows: the concentration of caustic soda solution was $0.07{\sim}0.1%$(w/v) and the contact time of brewers yeast slurry with caustic soda was $10{\sim}20$ minutes. The similar washing effect was obtained when the brewers yeast slurry was washed with 20%(v/v) ethanol solution.

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Modelling of the Heat and Mass Transfer in a Liquid Desiccant Dehumidifier with Extended Surface (확장표면을 적용한 액체식 제습기의 열물질 전달 모델링)

  • Chang, Y.S.;Lee, D.Y.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.23 no.4
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    • pp.303-311
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    • 2011
  • This study presents a new idea of liquid desiccant dehumidifier with extended surface to improve the compactness. Extended surface is inserted between vertical cooling tubes, and the liquid desiccant flows down along the tube walls and the extended surface as well. Though the extended surface contributes to the increase in the mass transfer area, the effect tends to be limited because less conductive non-metallic materials need to be applied due to the high corrosiveness of liquid desiccant. To analyze the effects of the extended surface insertion, mathematical modelling and numerical integration are performed for the heat and mass transfer in the liquid desiccant dehumidifier. The results show that, though the liquid desiccant on the extended surface is heated due to the moisture absorption, the temperature can be maintained by periodic mixing at the contact points between the tube and the extended surface with the liquid desiccant stream from the tube side at a relatively low temperature. This implies the absorption heat from the extended surface side can be removed effectively by mixing, which leads to a substantial improvement of the dehumidification in the liquid desiccant dehumidifier with extended surface. When the interval of the extended surface, $p_e/L$, is less than 0.1, the dehumidification is shown to increase by more than two times compared with that without extended surface.

The Effect of Salt in Medicine for Salt Pharmacopuncture (염약침(鹽藥鍼)을 위한 소금의 의학적 효용)

  • Kim, Kee Hyun;Kim, Jee Hwa;Song, Ho Sueb
    • Journal of Acupuncture Research
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    • v.32 no.2
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    • pp.131-145
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    • 2015
  • Objectives : The purpose of this study was to demonstrate the effectiveness and availability of salt pharmacopuncture of Korean sun-dried salt and processing salt on the basis of bibliographical review. Methods : This study was done through a narrative review of related bibliography including medical books, journals, general bibliography, and web sites. Results : 1. Korean sun-dried salt is produced in the ground with soil, tiles, and pottery. Sun-dried, traditional, granulated, bamboo, and grilled salts are all appropriate for medical use. They are composed of a lower level of NaCl and unnecessary substances, and have a higher water and mineral content. 2. The 9~30 g of NaCl included in the physiological saline matches the ratio of a normal human body. However, if the saline is used for water supply, it should be improved because the recommended amount is much lower. 3. Medicine that includes NaCl is applied for lessening the congestion of the nasal cavity, alleviating cornea swelling, or for a lack of water. NaCl can also be used for washing contact lenses as well as cleaning the mucous membrane of the eyes and nose. 4. Salt relieves anger, detoxifies, induces vomiting, builds strong muscles and bones, gives energy, slows aging, and ultimately improves health. 5. Salt treats many diseases including: cardiovascular, hematosis, respirometer, obstetric, musculoskeletal, mineral supplement, eye, teeth and skin issues, etc.. However, salt is not used for treating asthma, cough, or other ailments mainly affecting the vascular system. 6. While NaCl in salt absorbs water and the vascular constriction results in higher blood pressure, the pressure induced from salt is actually a physiologically temporary rise. Rather, salt helps remove oil from the body and its potassium lowers blood pressure. Conclusions : It was suggested that salt pharmacopuncture of Korean sun-dried salt and processing salt should be made available for adjusting the physiological salt concentration and control of the Na side effects, therefore it would be useful in the treatment of diseases.

Effects of rapid thermal annealing on Physical properties of polycrystalline CdTe thin films (급속열처리가 다결정 CdTe 박막의 물성에 미치는 효과에 관한 연구)

  • 조영아;이용혁;윤종구;오경희;염근영;신성호;박광자
    • Journal of the Korean Vacuum Society
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    • v.5 no.4
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    • pp.348-353
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    • 1996
  • Rapid thermal annealing (RTA) was applied to polycrystalline CdTe thin films evaporated on CdS/ITO/glass substrate and the effect of the annealing temperatures and the atmosphere on physical properties of polycrystalline CdTe thin films and CdTe/CdS solar cell characteristics were studied. Results obtained by EDX showed that the bulk composition of CdTe remained stoichiometric after annealing at $550^{\circ}C$ in the air but the surface composition became Cd-rich. Cross-sectional TEM and micro EDX showed that columnar grains and micro-twins remained even after RTA, however, and the sulfur content in the annealed CdTe (added by sulfur diffusion from CdS during the annealing) was much smaller than that by furnace annealing. Among the investigated RTA temperatures and gas environments, the cell made with CdTe annealed at $550^{\circ}C$ in air showed the best solar energy conversion efficiency.

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Effect of Urethane Modification on the Anti-Bullet Property of Dyneema/vinylester Composites (우레탄 수지 첨가에 의한 다이니마/비닐에스터 복합재료의 방탄효과 향상 연구)

  • Yoon, T.H.;Cha, Y.M.;Yuck, J.I.;Paik, J.G.;Oh, Y.J.;Kim, H.J.
    • Composites Research
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    • v.24 no.6
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    • pp.7-11
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    • 2011
  • Polyurethane oligomers (PUOs) such as UA8297, UP127 and EB8200 were utilized to enhance the anti-bullet property of Dyneema$^{(R)}$/vinylester composites. First, prepregs of PUO and vinylester (XSR10) were prepared via spray coating on Dyneema$^{(R)}$ fabric at 21 % resin content (by volume). In addition, spray coating and film lamination were also carried out with a mixture of XSR10/PUO for selected PUOs. Next, the prepregs were dried at RT for 1-2 h and then at $100^{\circ}C$ for 30 min to remove the solvent and to provide partial cure when necessary. The prepregs were stacked in 24 layers and cured at $120^{\circ}C$ for 5 min under the contact pressure and for additional 25 min at 150 $kg/cm^2$. Finally, the anti-bullet properties of composite samples were evaluated by measuring $V_{50}$ with simulated fragment projectile (SFP, 17 gr). The results showed a 6.5 and 9.0 % increase of $V_{50}$ with UP127 and EB8200, respectively.

Effect of Tactile Feedback on Trunk Posture and EMG Activity in People With Postural Kyphosis During VDT Work

  • Park, Joo-hee;Kang, Sun-young;Cynn, Heon-seock;Jeon, Hye-seon
    • Physical Therapy Korea
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    • v.23 no.3
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    • pp.48-56
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    • 2016
  • Background: Recently, there has been an emphasis on the use of interventions with biofeedback information for the maintenance or correction of posture. Objects: This study assessed the change of trunk posture and trunk muscle activation when people exhibiting postural kyphosis performed visual display terminal work with or without a contact feedback device (CFD). Methods: Eighteen right-handed individuals were recruited. Thoracic angle and right thoracic erector spinae (TES) muscle amplitude were analyzed. There were two sessions in these experiments. The control session involved 16 minutes of typing without a CFD, and the CFD session involved 16 minutes of typing with a CFD. The visual analog scale score was analyzed with a paired t-test, and the kinematic and electromyography data were analyzed through two-way repeated analysis of variance. Results: The paired t-tests revealed that subjects had significantly less pain after the CFD sessions than after the control sessions (p<.05). Significant main effects by session and by time were observed in the thoracic kyphosis angle (p<.05). There was a significant session${\times}$time interaction for TES amplitude (p<.05), along with significant main effects by session and by time (p<.05). Conclusion: The CFD caused people with postural kyphosis to straighten and to activate their TES continuously, even though they were habituated to bend their bodies forward. Therefore, the CFD was a beneficial treatment tool.

An Analysis of Research on the Sensory Stimulation in Newborn Infants in Korea (신생아 감각자극에 관한 국내 연구 논문 분석)

  • Lee Kun-Ja;Lee Myung-Hee
    • Child Health Nursing Research
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    • v.8 no.3
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    • pp.322-333
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    • 2002
  • Purpose: The purpose of study was : 1) to analyse the trend of research on the sensory stimulation in newborn in Korea, 2) to suggest direction for further study on the sensory stimulation in newborn and contributing to the use of intervention in newborn. Method: Research studies on the sensory stimulation in newborn were selected from the dissertations, parents-child health. Academic Society Journal, and from Korean Journal of Pediatrcs which were conducted between 1984 and 2002. The total numbers of the studies were 15. These studies were analyzed for 1) time of publication or presentation 2) thesis for a degree or nondegree 3) characteristics of subjects 4) sample size 5) research design 6) type of sensory stimualtion 7) meaurement tool 8) result. Result : 1)The most year of studies were the 1996's~ 2000's. 2) The degree of studies were higher than nondegree. 3) The most characteristics of subjects were the premature infants. 4) The most frequent sample sizes were 11-20. 5) The all research design was nonequivalent control group pretest-posttest design in quasi experimental basis. 6) The most type of sensory stimulation was Field massage(tactile and kinesthetic). 7) The measurement tool used all objective tools. 8) The most research data were collected by the measure of the weight, heart rate, behavior state, respiration, stress hormon and positive results. Conclusion: 1) Human sensory stimulation did not seem to harm the infants. 2) several positive effects of sensory stimulation that have been reported previously must be reevaluated. 3) further research will be required large sample size, long-term outcome, individualized stimulation program, early parent-infant contact in order to enhance the development of attachment, to determine the underlying mechanism and theorical frame for these stimulation effect.

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