• Title/Summary/Keyword: human pressure

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Biomechanical Study of Lumbar Spinal Arthroplasty with a Semi-Constrained Artificial Disc (Activ L) in the Human Cadaveric Spine

  • Ha, Sung-Kon;Kim, Se-Hoon;Kim, Daniel H.;Park, Jung-Yul;Lim, Dong-Jun;Lee, Sang-Kook
    • Journal of Korean Neurosurgical Society
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    • v.45 no.3
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    • pp.169-175
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    • 2009
  • Objective : The goal of this study was to evaluate the biomechanical features of human cadaveric spines implanted with the Activ L prosthesis. Methods : Five cadaveric human lumbosacral spines (L2-S2) were tested for different motion modes, i.e. extension and flexion, right and left lateral bending and rotation. Baseline measurements of the range of motion (ROM), disc pressure (DP), and facet strain (FS) were performed in six modes of motion by applying loads up to 8 Nm, with a loading rate of 0.3 Nm/second. A constant 400 N axial follower preload was applied throughout the loading. After the Activ L was implanted at the L4-L5 disc space, measurements were repeated in the same manner. Results : The Activ L arthroplasty showed statistically significant decrease of ROM during rotation, increase of ROM during flexion and lateral bending at the operative segment and increase of ROM at the inferior segment during flexion. The DP of the superior disc of the operative site was comparable to those of intact spine and the DP of the inferior disc decreased in all motion modes, but these were not statistically significant. For FS, statistically significant decrease was detected at the operative facet during flexion and at the inferior facet during rotation. Conclusion : In vitro physiologic preload setting, the Activ L arthroplasty showed less restoration of ROM at the operative and adjacent levels as compared with intact spine. However, results of this study revealed that there are several possible theoretical useful results to reduce the incidence of adjacent segment disease.

Effects of the AngiotensinII $AT_1$ Receptor Antagonist SK-1080 on Ischemia/reperfusion in Isolated Rat Hearts and on Platelet Aggregation and Coagulation in Human Blood (Angiotensin II $AT_1$ 수용체 길항제인 SK-1080의 적출심장에 대한 허혈후 재관류시의 작용 및 혈소판응집과 혈액응고에 대한 효과)

  • Woo, Su-Kyoung;Choi, Sang-Su;Lee, Byung-Ho;Kwon, Kwang-Il
    • YAKHAK HOEJI
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    • v.44 no.6
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    • pp.558-565
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    • 2000
  • SK-1080 is one of the newly developed orally active nonpeptide angiotensinII $AT_1-receptor$ antagonist that selectively acts at $AT_1$ receptor with high affinity. The cardiac effect on ischemia/reperfusion injury of SK-1080 was compared with those of losartan, a prototype of this class, in isolated rat hearts. Isolated perfused rat heart was pretreated with drug for 10 min and then subjected to global ischemia for 30 min followed by reperfusion with- or without drug for 30 min. The possible additive effect of SK-1080 on the platelet aggregation and coagulation in human blood was also studied. We investigated whether SK-1080 effects the platelet aggregation induced by ADP, a platelet agonist partially dependent on $thromboxaneA_2$. The clotting times in the prothrombin time (PT) and activated partial thromboplastin time (APTT) were also examined in human plasma in vitro as coagulation screening test. SK-1080 improved reperfusion function (LVDP, left ventricular developed pressure; PRP, rate-pressure product) in a dose-dependent manner. SK-1080 reduced ADP-induced platelet aggregation compared with vehicle but less than losartan, and did not affect clotting times.

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The Relationship between Personality Factors and Characteristics of Human Figure in Kinetic Family Drawing among High-school Girls (여고생의 인성과 동적가족화(KFD)에 나타난 인물상의 특성과의 관계)

  • Kim Gab-Sook;Jeon Young-Sook
    • Journal of Families and Better Life
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    • v.23 no.6 s.78
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    • pp.79-93
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    • 2005
  • The study investigated whether the characteristics of human figures in Kinetic Family Drawing showed significant differences according to the drawer's personality (neurosis, intellectual openness, friendliness, extroversion, sincerity). The participants of this study were 340 high-school girls. The Five Factors Personality Test was conducted to assess personality factors and the Kinetic Family Drawing Test was used to obtain data on drawing characteristics. The data were analyzed using Chi-square. The results of this study are as follows: First, there were significant differences in ten subcategories such as face, countenance, eyes, mouth, inclusion of body. hands, posture, erasure, exertion of pressure on the paper, and lines, according to the degree of neurosis. Second, there were significant differences in countenance, eyes, posture, exertion of pressure on the paper, and lines according to the degree of extroversion. Third, there were significant differences in face, countenance, eyes, and posture, according to the degree of openness. Fourth, there were significant differences in erasure and lines according to the degree of friendliness Fifth, there were significant differences in countenance and posture according to the degree of sincerity. This study proved that among the personality factors, neurosis is most highly related with characteristics of persons drawn in the Kinetic Family I)lawing, whereas countenance and posture in the drawing were highly indicative of personality factors.

A Study on Estimation of Human Damage for Overpressure by Vapor Cloud Explosion in Enclosure Using Probit Model (프로빗모델을 통한 밀폐공간에서의 증기운폭발 과압에 의한 인체피해예측)

  • Leem, Sa-Hwan;Lee, Jong-Rark;Huh, Yong-Jeong
    • Journal of the Korean Institute of Gas
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    • v.12 no.1
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    • pp.42-47
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    • 2008
  • The demand of gas as an eco-friendly energy source has being increased. With the demand of gas, the use of gas is also increased, so injury and loss of life by the explosion and fire have been increasing every year. Hence the influence on over-pressure caused by Vapor Cloud Explosion in enclosure of experimental booth was calculated by using the Hopkinson's scaling law and damage effect by the accident to a human body was estimated by applying the probit model. As a result of the damage estimation conducted by using the probit model, both the damage possibility of explosion overpressure to human over 3 meters away and that of overpressure to tympanum rupture over 25 meters away from the explosion shows nothing.

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Optimization of Fermentation Conditions for Production of Recombinant Human Interleukin-2 in Escherichia coli (대장균에서의 재조합 인체 인터루킨-2 생산을 위한 발효조건 최적화)

  • Lee, In-Young;Kim, Myung-Kuk;Na, Doe-Sun;Hahm, Kyung-Soo;Moon H. Han;Lee, Sun-Bok
    • Microbiology and Biotechnology Letters
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    • v.16 no.4
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    • pp.327-333
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    • 1988
  • For optimal production of recombinant human interleukin-2 (IL-2) in E. coli the effect of fermentation conditions on cell growth, IL-2 production, and stability of recombinant cells were investigated. Among the complex nutrients tested in this work, yeast extract, peptone and corn steep liquor were found to be effective for recombinant cell growth. The recombinant cells were maintained stably under repression condition (3$0^{\circ}C$), but the stability of recombinant cells were drastically reduced upon induction of IL-2 expression (42$^{\circ}C$) even under the selection pressure. Addition of antibiotics to the culture medium resulted in the cell growth inhibition without significant improvement in recombinant stability. When the expression of IL-2 gene was induced at different growth phases, highest IL-2 production was achieved by the induction of IL-2 at the middle-exponential growth phase. It was found that the production of IL-2 significantly inhibited the cell growth and the ex-pression of other genes in the plasmid.

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Relative and Attributable Risks of Obesity, Hypertension and Hyperglycemia to Hypercholesterolemia in Korean Adult Males (한국 성인 남자의 고콜레스테롤혈증에 대한 비만, 고혈압 및 고혈당의 상대적 위험도 및 기여도)

  • 허영란;임현숙
    • Korean Journal of Human Ecology
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    • v.2 no.1
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    • pp.80-88
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    • 1999
  • Hypercholesterolemia is a well known major risk factor for cardiovascular disease, now the leading cause of death in Korea. This study was carried out to examine the relationships of hypercholesterolemia(HC$\geq$240 mg/dL) with obesity, blood pressure and blood glucose level in 649 male subjects aged 20-69 in Kwangju, Korea. The mean plasma total cholesterol level was 212${\pm}$43 mg/dL, and 25.3% of the subjects was diagnosed as HC and 39.3% as nomorcholesterolemia(NC〈200 mg/dL). The prevalence of HC seemed to increase with age. The subjects with HC were highly overweighted and had higher body mass index(BMI) than the NC subjects. The incidence of overweight(25$\leq$BMI〈30) and obesity(BMI$\geq$30) among the HC subjects were 44.5%, and 1.8%, respectively. The HC subjects had higher systolic(SBP) and diastolic blood pressure(DBP) than the NC subjects. The incidence of borderline hypertension (160/95〉SBP/DBP$\geq$140/90) and hypertension(SBP/DBP$\geq$160/95) among the HC subjects were 18.3%, and 9.1%, respectively. However, there was no difference in blood glucose level between the HC and NC subjects. The plasma total cholesterol level had positive relationships with BMI(P〈0.001), weight(P〈0.001), DBP(P〈0.001), SBP(P〈0.01), and age(P〈0.01), whereas inverse relationships with height/weight ratio(P〈0.001), and height(P〈0.01). The relative risks on HC were 1.99 for obesity, 1.53 for overweight, 1.82 for hypertension, 1.44 for borderline hypertension and 1.08 for hyperglycemia. Attributable risks on HC were 0.25 for obesity, 0.11 for overweight, 0.20 for hypertension, 0.10 for borderline hypertension and 0.02 for hyperglycemia. The results indicate that the level of plasma total cholesterol was closely associated with the incidences of obesity and hypertension. (Korean J of Human Ecology 2(1) : 80-88, 1999)

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Evaluation of the Cochlear Electrode Behavior in the 3D Human Cochlea Model by FEM Analysis (3차원 달팽이관 모델에서의 인공와우 전극의 거동에 대한 유한요소해석)

  • 임윤섭;박세익;김용협;오승하;김성준
    • Journal of Biomedical Engineering Research
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    • v.25 no.3
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    • pp.207-215
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    • 2004
  • A finite element analysis is used in this study to model 6 kinds of electrode by a genetic program in order to evaluate the mechanical effect on the 3D human cochlea model and the behavior of electrode. Human cochlea is modeled by the spiral-approximation method and the shape of scala tympani is extracted from the mid section of the human cochlea. Contact pressure at the tip and the insertion force are found to be highest when the wires stack horizontally. Axial rotation of electrode is minimal comparing with the stimulating current spread. The results indicate that the electrode stiffness is important to minimize the trauma.

Comparison of Human Responses to Transportation Noise in Monaural and Binaural Hearing, Part I: Measurement and Analysis (교통소음의 모노럴과 바이노럴 청감 비교 연구 I: 측정 및 분석)

  • Kim, Jaehwan;Lim, Chang-Woo;Jeong, Wontae;Hong, Jiyoung;Cheung, Wansup;Lee, Soogab
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.12
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    • pp.1268-1278
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    • 2004
  • Measurement of noise is not only to know the information of acoustic pressure but to assess human response to noise. To find human response to transportation noise through the laboratory study we have to measure and reproduce noise. The method of noise reproduction is largely divided into monaural and binaural techniques. But human fundamentally hears sound through both ears, referred as binaural hearing. Binaural signal is different from monaural signal because it includes more information of physical phenomena like acoustical reflection, diffraction and refraction. Especially head and pinna play an important role in perceiving change of signal origin. So, the amplitude of binaural signal is higher than that of monaural signal and spectrum of both signals is discriminated. Most of assessment and regulation of transportation noise are, however, based on monaural measurement techniques. The quantitative difference between monaural and binaural measurement is investigated in this study. Comparison on several transportation noisesshows defect of information in monaural measurements.

Measurement Criteria for Drag-Sled Type Slip Resistance Tester Based on Human Gait and Slip (인간의 보행 및 미끄러짐 특성에 기반한 끌기형 미끄러짐 저항 측정 조건)

  • Park, Jae-Suk;Kwon, Hyuck-Myun;Oh, Whan-Sup
    • Journal of the Korean Society of Safety
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    • v.27 no.5
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    • pp.179-184
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    • 2012
  • This study was performed to find out the measurement criteria of slip resistance from analysis of human gait and slips. Many kinds of slip resistance testers were developed based on mechanical friction testers. But, there are, as yet, no unambiguous slip resistance measurement methodologies and generally accepted safety criteria or safety thresholds for estimating slipping hazard exposures. Also, there are variety of measuring conditions between those testers. The measurement criteria should be tested within the range of human slipping conditions observed in biomechanical studies. It's results should clearly consider whether the devices reflect the human slipping conditions. In this study a dragsled type friction tester, which was constructed in accordance with ISO 15133 basically, was used. Test conditions were set in order to determine the range of measurement criteria. It is shown that drag velocity should be more than 1 m/s, acceleration be more than 10 $m/s^2$, contact time be less than 0.1sec, and contact pressure be within 350~400 kPa.

Inhibitory Effects of Extracts of Houttuynia cordata Thumb (Saururaceae) on Cytokine Release of Human Monocytic THP-1 Cells and Human Eosinophilic EoL-1 Cells

  • Lee, Ji-Sook
    • Biomedical Science Letters
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    • v.16 no.4
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    • pp.341-347
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    • 2010
  • In the present study, we investigated whether Houttuynia cordata Thumb (Saururaceae; HC) extracts have an anti-inflammatory effect in human monocytic THP-1 cells and human eosinophilic EoL-1 cells. The dried and powdered whole plants of HC were extracted with 80% EtOH. The combined extract (HC-1) was concentrated under reduced pressure. The residue was diluted with water, and then successively partitioned with n-hexane, EtOAc, and BuOH to produce the n-hexane (HC-2), EtOAc (HC-3), BuOH (HC-4), and the water-soluble fractions (HC-5), respectively. HC extracts have no cytotoxicity on THP-1 cells and EoL-1 cells at a high concentration of $10\;{\mu}g/ml$ for 24 h, except HC-2 extract ($10\;{\mu}g/ml$). Interleukin-6, Interleukin-8 and Monocyte chemoattractant protein-1 in THP-1 cells were increased after the treatment with the extract from house dust mite or LPS. The increase of cytokine production was strongly suppressed by HC-3 extract, in comparision with other extracts. HC-3 also had inhibitory effect on Interleukin-6 production increased by mite extract and LPS in EoL-1 cells. However, HC-3 extract increased Interleukin-8 production induced by mite extract and LPS in EoL-1 cells. These results suggest that HC extracts may be used as useful agents for treating allergic disorders such as asthma and atopic dermatitis.