• Title/Summary/Keyword: 2-phase model

Search Result 2,349, Processing Time 0.04 seconds

Purification of Materials Produced by Amylocolatosis sp. and Anticancer Effect in Oral Cancer Model (Amylocolatosis sp.가 생산하는 항암물질의 정제 및 구강암 모델에 미치는 항암 효과)

  • Kim, Jung;Park, Young-Min;Lim, Do-Seon
    • Journal of dental hygiene science
    • /
    • v.3 no.1
    • /
    • pp.11-14
    • /
    • 2003
  • A methylotrophic Actinomycetes strain, which produce the anti-oral cancer activity compound, was isolated from soil and estimated as Amylocolatosis sp. based on taxonomic studies. A methanol didn't have influence on the production of the anticancer compounds. These compound were isolated by ethylacetate extract, silica gel column chromatography, sephadex LH-20 column and reverse phase HPLC. The compounds were very stable under heat ($121^{\circ}C$), acid(pH 2.0) and alkali(pH 11.0) treatment. The cytotoxic effect of isolated anticancer compounds on various cancer cell lines such as A549, SNU-1, KB, L1210, and Sarcoma 180 was investigated by MTT assay method. And these produced compounds also showed the broad antimicrobial spectrum to test strains such as bacteria and yeast.

  • PDF

Determination of Initial Beam Parameters of Varian 2100 CD Linac for Various Therapeutic Electrons Using PRIMO

  • Maskani, Reza;Tahmasebibirgani, Mohammad Javad;Hoseini-Ghahfarokhi, Mojtaba;Fatahiasl, Jafar
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.16 no.17
    • /
    • pp.7795-7801
    • /
    • 2015
  • The aim of the present research was to establish primary characteristics of electron beams for a Varian 2100C/D linear accelerator with recently developed PRIMO Monte Carlo software and to verify relations between electron energy and dose distribution. To maintain conformity of simulated and measured dose curves within 1%/1mm, mean energy, Full Width at Half Maximum (FWHM) of energy and focal spot FWHM of initial beam were changed iteratively. Mean and most probable energies were extracted from validated phase spaces and compared with related empirical equation results. To explain the importance of correct estimation of primary energy on a clinical case, computed tomography images of a thorax phantom were imported in PRIMO. Dose distributions and dose volume histogram (DVH) curves were compared between validated and artificial cases with overestimated energy. Initial mean energies were obtained of 6.68, 9.73, 13.2 and 16.4 MeV for 6, 9, 12 and 15 nominal energies, respectively. Energy FWHM reduced with increase in energy. Three mm focal spot FWHM for 9 MeV and 4 mm for other energies made proper matches of simulated and measured profiles. In addition, the maximum difference of calculated mean electrons energy at the phantom surface with empirical equation was 2.2 percent. Finally, clear differences in DVH curves of validated and artificial energy were observed as heterogeneity indexes were 0.15 for 7.21 MeV and 0.25 for 6.68 MeV. The Monte Carlo model presented in PRIMO for Varian 2100 CD was precisely validated. IAEA polynomial equations estimated mean energy more accurately than a known linear one. Small displacement of R50 changed DVH curves and homogeneity indexes. PRIMO is a user-friendly software which has suitable capabilities to calculate dose distribution in water phantoms or computerized tomographic volumes accurately.

Bone regeneration of the fluoridated hydroxyapatite and the bio-glass in the rabbit cranium defect model (가토 두개골 결손 모델에서 Bioglass가 첨가된 불소화 수산화인회석의 골재생능력)

  • Ahn, Hyo-Joon;Han, Se-Jin;Kim, Kyung-Wook
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • v.37 no.5
    • /
    • pp.380-385
    • /
    • 2011
  • Introduction: Hydroxyapatite ($Ca_{10}(PO_4)_6(OH)_2$, HA) is the main inorganic phase of human hard tissue that is used widely as the repair material for bones. When HA is applied to a bony defect, however, it can be encapsulated with fibrous tissue and float in the implanted area due to a lack of consolidation. Bioceramics as allogenic graft materials are added to HA to improve the rate and bone healing capacity. Fluoridated hydroxyapatite ($Ca_{10}(PO_4)_6(OH,F)_2$, FHA), where F- partially replaces the OH- in hydroxyapatite, is considered a good alternative material for bone repair owing to its solubility and biocompatibility. Materials and Methods: This study was designed to determine the bone healing capacity of FHA newly produced as a nanoscale fiber in the laboratory. HA and FHA with bioglass was implanted in a rabbit cranium defect and the specimen was analysed histologically. Results: 1. At 4 weeks, fibrous connective tissue and little bone formation was observed around the materials of the experimental group I implanted HA and bioglass. Newly formed bone was observed around the materials in the experimental group II implanted FHA and bioglass. 2. At 8 weeks, the amount of newly formed and matured bone was higher in experimental group II than in experimental group I and the control group. Conclusion: These results suggest that FHA and bioglass is a relatively favorable bone substitute with biocompatibility and better bone healing capacity than pure HA and bioglass.

A Mathematical Modeling of Two-Dimensional Unsteady Flow for Long Waves in a Harbor (항내(港內) 장주기파(長週期波) 해석(解析)을 위한 2차원(二次元) 부정류(不定流)의 수학적(數學的) 모형(模型))

  • Lee, Jong Tae;Lee, Won Hwan
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.3 no.1
    • /
    • pp.13-24
    • /
    • 1983
  • A mathematical model for the two-dimensional unsteady flow was developed by introducing Abbott's implicit finite difference operator and double sweep algorithm, which could be applied to simulate the respose of a harbor against the intrusion of long waves through the entrance connected to open sea. In order to improve its accuracy corresponding to the field phenomena, bottom resistance, Coriolis force, wind effect terms were included and wave direction and radiating effect was considered. The result of seiche test was always stable and the amplitude was accurate. Some phase shift was occured, but it could be reduced by using small values of Courant number and many points per a wave length as well. A comparision with the Ippen and Goda's theoritical and hydraulic experimental works was fulfilled.

  • PDF

A Study on Changes in Biomechanical Characteristics of the Foot with Respect to Wedge-type Insole Thickness (키높이 인솔두께에 따른 족부의 생체역학적 특성변화에 대한 연구)

  • Park, T.H.;Jung, T.G.;Han, D.W.;Lee, Sung-Jae
    • Journal of Biomedical Engineering Research
    • /
    • v.34 no.2
    • /
    • pp.80-90
    • /
    • 2013
  • Recently, functional insoles of wedge-type it is for the young to raise their height inserted between insole and heel cause foot pain and disease. Additionally, these have a problem with stability and excessively load-bearing during gait like high-heel shoes. In this study, we compared the changes in biomechanical characteristics of foot with different insole thickness then we will utilize for the development of the insole with the purpose of relieving the pain and disease. Subjects(male, n = 6) measured COP(center of pressure) and PCP(peak contact pressure) on the treadmill(140cm/s) using F-scan system and different insole thickness(0~50 mm) between sole and plantar surface during gait. Also, we computed changes of stresses at the foot using finite element model with various insole thickness during toe-off phase. COP moved anterior and medial direction and, PCP was increased at medial forefoot surface, $1^{st}$ and $2^{nd}$ metatarsophalangeal, ($9%{\uparrow}$) with thicker insoles and it was show sensitive increment as the insole thickness was increased from 40 mm to 50 mm. Change of the stress at the soft-tissue of plantar surface, $1^{st}$ metatarsal head represents rapid growth($36%{\uparrow}$). Also, lateral moments were increased over the 100% near the $1^{st}$ metatarsal as the insole thickness was increased from 0 mm to 30 mm. And it is show sensitive increment as the insole thickness changed 10 mm to 20 mm. As a result, it was expected that use of excessively thick insoles might cause unwanted foot pain at the forefoot region. Therefore, insole thickness under 30 mm was selected.

Numerical simulations of the vertical kink oscillations of the solar coronal loop with field aligned flows

  • Pandey, V.S.;Magara, T.;Lee, D.H.;Selwa, M.
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.36 no.2
    • /
    • pp.103.1-103.1
    • /
    • 2011
  • Recent observations by Hinode show weakly-attenuated coronal loop oscillations in the presence of background flow (Ofman & Wang 2008, A&A, 482, L9). We study the vertical kink oscillations in solar coronal loops, considering field aligned flows inside the loops as well as surrounding the loops environment. The two dimensional numerical model of straight slab is used to explore the excitation and attenuation of the impulsively triggered fast magnetosonic standing kink waves. A full set of time dependent ideal magnetohydrodynamics equations is solved numerically taking into account the value of flow of the order of observed flows detected by SOT/Hinode. We find that relaxing the assumption of the limited flows within the loops enhances the damping rate of the fundamental mode of the standing kink waves by 2 - 3 % as compared to flow pattern which is basically localized within the loops. We further notice that extending the flow pattern beyond the loop thickness also enhances the strength of the shock associated with slow magnetoacoustic waves, recognized as an addition feature detected in the numerical simulation. The wider out-flow pattern destroys the oscillation patterns early as compared to narrower flow pattern, in other words we can say that it affects the durability of the oscillation. However, for the typical coronal loops parameters we find that the observed durability periods of the SOT/Hinode observation can be achieved with an out-flow Gaussian patterns for which half-width is not greater than factor 2.0 of the loop-half-width. explain a possible relation between electric current structure and sigmoid observed in a preflare phase.

  • PDF

The Effects of the Mixture of Herbal Extract on Developing Plaque and Gingivitis (생약복합제재에 의한 구강양치가 치태 및 치은염에 미치는 영향)

  • Shin, Sug-Rang;Kim, Sung-Jo
    • Journal of Periodontal and Implant Science
    • /
    • v.28 no.2
    • /
    • pp.377-388
    • /
    • 1998
  • This double-blind controlled clinical and microbiological study was carried out to determine the effects of mouthwash preparation containing the mixture of herbal extract on developing plaque and gingivitis in the experimental gingivitis model. Following a 2-week normalization period, 34 dental students were distributed randomly into 1 of 3 treatment groups. They rinsed, under supervision, two times daily for 3 weeks with either normal saline(CT), 0.1% chlorhexidine(CH), or the mixture of herbal extract (HT), but refrained from any oral hygiene measures. The Plaque Index(PlI), the Gingival Index(GI), and the amount of Gingival Crevicular Fluid(GCF) were measured at week 0,1,2, and 3 of the experimental period, while the assessment of total wet weight of plaque and the phase contrast microscopic examination of plaque were performed at the end of experimental period(3 weeks). Subjects using mouthrinse preparation containing the mixture of herbal extract demonstrated negligible, if any, changes in the accumulation and microbial composition of plaque compared to those using normal saline, while the reduction of gingival inflammation by this mixture was highly significant and comparable to that of chlorhexidine. The results of this study indicate that the preparation containing the mixture of herbal extract do not provide any antiplaque benefits but is very effective in inhibiting the development of and in reducing existing experimental gingivitis when used as mouthrinse. Further research is needed to determine whether a significant reduction of gingival inflammation without a concomitant decrease in plaque accumulation is of clinical importance.

  • PDF

Comparison of serum amyloid A protein and C-reactive protein levels as inflammatory markers in periodontitis

  • Ardila, Carlos Martin;Guzman, Isabel Cristina
    • Journal of Periodontal and Implant Science
    • /
    • v.45 no.1
    • /
    • pp.14-22
    • /
    • 2015
  • Purpose: The purpose of this study was to compare serum amyloid A (SAA) protein levels with high-sensitive C-reactive protein (hs-CRP) levels as markers of systemic inflammation in patients with chronic periodontitis. The association of serum titers of antibodies to periodontal microbiota and SAA/hs-CRP levels in periodontitis patients was also studied. Methods: A total of 110 individuals were included in this study. Patients were assessed for levels of hs-CRP and SAA. Nonfasting blood samples were collected from participants at the time of clinical examination. The diagnosis of adipose tissue disorders was made according to previously defined criteria. To determine SAA levels, a sandwich enzyme-linked immunosorbent assay was utilized. Paper points were transferred to a sterile tube to obtain a pool of samples for polymerase chain reaction processing and the identification of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Tannerella forsythia. The serum level of IgG1 and IgG2 antibodies to P. gingivalis, A. actinomycetemcomitans, and T. forsythia was also determined. Results: SAA and hs-CRP levels were higher in periodontitis patients than in controls (P<0.05). In bivariate analysis, high levels of hs-CRP (>3 mg/L) and SAA (>10 mg/L) were significantly associated with chronic periodontitis (P=0.004). The Spearman correlation analysis between acute-phase proteins showed that SAA positively correlated with hs-CRP (r=0.218, P=0.02). In the adjusted model, chronic periodontitis was associated with high levels of SAA (odds ratio [OR], 5.5; 95% confidence interval [CI], 1.6-18.2; P=0.005) and elevated hs-CRP levels (OR, 6.1, 95% CI, 1.6-23.6; P=0.008). Increased levels of serum IgG2 antibodies to P. gingivalis were associated with high levels of SAA (OR, 3.6; 95% CI, 1.4-8.5; P=0.005) and high concentrations of hs-CRP (OR, 4.3; 95% CI, 1.9-9.8; P<0.001). Conclusions: SAA and hs-CRP concentrations in patients with chronic periodontitis are comparably elevated. High serum titers of antibodies to P. gingivalis and the presence of periodontal disease are independently related to high SAA and hs-CRP levels.

A "Dynamic Form-Finding" Approach to Environmental-Performance Building Design

  • Yao, Jia-Wei;Lin, Yu-Qiong;Zheng, Jing-Yun;Yuan, Philip F.
    • International Journal of High-Rise Buildings
    • /
    • v.7 no.2
    • /
    • pp.145-151
    • /
    • 2018
  • Newly-designed high-rise buildings, both in China and abroad, have demonstrated new innovations from the creative concept to the creative method. from the creative concept to the creative method. At the same time, digital technology has enabled more design freedom in the vertical dimension. "Twisting" has gradually become the morphological choice of many city landmark buildings in recent years. The form seems more likely to be driven by the interaction of aesthetics and structural engineering. Environmental performance is often a secondary consideration; it is typically not simulated until the evaluation phase. Based on the research results of "DigitalFUTURE Shanghai 2017 Workshop - Wind Tunnel Visualization", an approach that can be employed by architects to design environmental-performance buildings during the early stages has been explored. The integration of a dynamic form-finding approach (DFFA) and programming transforms the complex relationship between architecture and environment into a dialogue of computer language and dynamic models. It allows the design to focus on the relationship between morphology and the surrounding environment, and is not limited to the envelope form itself. This new concept of DFFA in this research consists of three elements: 1) architectural form; 2) integration of wind tunnel and dynamic models; and 3) environmental response. The concept of wind tunnel testing integrated with a dynamic model fundamentally abandons the functional definition of the traditional static environment simulation analysis. Instead it is driven by integral environmental performance as the basic starting point of morphological generation.

Apigenin causes necroptosis by inducing ROS accumulation, mitochondrial dysfunction, and ATP depletion in malignant mesothelioma cells

  • Lee, Yoon-Jin;Park, Kwan-Sik;Nam, Hae-Seon;Cho, Moon-Kyun;Lee, Sang-Han
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.24 no.6
    • /
    • pp.493-502
    • /
    • 2020
  • Apigenin, a naturally occurring flavonoid, is known to exhibit significant anticancer activity. This study was designed to determine the effects of apigenin on two malignant mesothelioma cell lines, MSTO-211H and H2452, and to explore the underlying mechanism(s). Apigenin significantly inhibited cell viability with a concomitant increase in intracellular reactive oxygen species (ROS) and caused the loss of mitochondrial membrane potential (ΔΨm), and ATP depletion, resulting in apoptosis and necroptosis in monolayer cell culture. Apigenin upregulated DNA damage response proteins, including the DNA double strand break marker phospho (p)-histone H2A.X. and caused a transition delay at the G2/M phase of cell cycle. Western blot analysis showed that apigenin treatment upregulated protein levels of cleaved caspase-3, cleaved PARP, p-MLKL, and p-RIP3 along with an increased Bax/Bcl-2 ratio. ATP supplementation restored cell viability and levels of DNA damage-, apoptosisand necroptosis-related proteins that apigenin caused. In addition, N-acetylcysteine reduced ROS production and improved ΔΨm loss and cell death that were caused by apigenin. In a 3D spheroid culture model, ROS-dependent necroptosis was found to be a mechanism involved in the anti-cancer activity of apigenin against malignant mesothelioma cells. Taken together, our findings suggest that apigenin can induce ROS-dependent necroptotic cell death due to ATP depletion through mitochondrial dysfunction. This study provides us a possible mechanism underlying why apigenin could be used as a therapeutic candidate for treating malignant mesothelioma.