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Free radical scavenging activity of some Bangladeshi plant extracts

  • Uddin, Shaikh Jamal;Shilpi, Jamil Ahmad;Delazar, Abbas;Nahar, Lutfun;Sarker, Satyajit Dey
    • Advances in Traditional Medicine
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    • v.4 no.3
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    • pp.187-195
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    • 2004
  • A number of plants from different geographical origins have been shown to possess antioxidant activity. Some of them have been developed as natural antioxidant formulations for food, cosmetic and other applications. Bangladeshi flora is a rich source of a range of plant species, many of which are medicinal plants, and have been used in the preparations of the Unani and Ayurvedic traditional medicines. There are no, or just a few, reports on any systematic screening of the extracts of Bangladeshi plants for free radical scavenging activity using DPPH assay available to date. As part of our on-going search for biological activity in Bangladeshi plants, Kadam (Anthocephalus chinensis), Goran (Ceriaps decandra), Swarnalata (Cuscuta reflexa), Gab (Diospyros peregrina), Sundari (Heritiera fomes), Dhundul (Xylocarpus granatum) and Possur (Xylocarpus mekongensis) have been selected for the assessment of their free radical scavenging activity, and studies on the contents of alkaloids, anthraqunones, flavonoids and tannins in these extracts. Most of these species have been used in traditional medicine in Bangladesh and other countries for the treatment of various illnesses ranging from common cold to cancer. All extracts, except the methanol extract of Cuscuta reflexa, displayed significant free radical scavenging activity in the DPPH assay $(RC_{50}$ values within the range of $2.75\;{\times}\;10^{-2}\;to\;4.7\;{\times}\;10^{-3}\;mg/mL)$. Among these extracts, the methanol extract of Xylocarpus granatum exhibited the most potent activity $(4.7\;{\times}\;10^{-3}\;mg/mL)$ and that of Cuscuta reflexa had the least activity $(1.64\;{\times}\;10^{-1}\;mg/mL)$. While none of these plants showed positive tests with Dragendorff's reagent, presence of low to moderate amounts of phenolic compounds, e.g. anthraquinones, flavonoids and tannins was evident in all of these plants, except for the methanolic extracts of C. reflexa and the barks of D. peregrina, which did not display any evidence for the presence of flavonoids and anthraquinones, respectively.

Results of Intravesical Chemo-Hyperthermia in High-risk Non-muscle Invasive Bladder Cancer

  • Ekin, Rahmi Gokhan;Akarken, Ilker;Cakmak, Ozgur;Tarhan, Huseyin;Celik, Orcun;Ilbey, Yusuf Ozlem;Divrik, Rauf Taner;Zorlu, Ferruh
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.8
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    • pp.3241-3245
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    • 2015
  • Purpose: To examine the effectiveness of mitomycin-C and chemo-hyperthermia in combination for patients with high-risk non-muscle-invasive bladder cancer. Materials and Methods: Between November 2011-September 2013, 43 patients with high-risk non-muscle-invasive bladder cancer undergoing adjuvant chemo-hyperthermia in two centers were evaluated retrospectively. Treatment consisted of 6 weekly sessions, followed by 6 sessions. Recurrence and progression rate, recurrence-free interval and side effects were examined. Analyzed factors included age, gender, smoking status, AB0 blood group, body mass index, T stage and grade, concominant CIS assets. The associations between predictors and recurrence were assessed using multivariate Cox proportional hazard analyses. Results: A total of 40 patients completed induction therapy. Thirteen (32.5%) were diagnosed with tumor recurrence. Median follow-up was 30 months (range 9-39). Median recurrence-free survival was 23 months (range 6-36). The Kaplan-Meier-estimated recurrence-free rates for the entire group at 12 and 24 months were 82% and 61%. There was no statistically significant difference between patient subgroups. Cox hazard analyses showed that an A blood type (OR=6.23, p=0.031) was an independent predictor of recurrence-free. Adverse effects were seen in 53% of patients and these were frequently grades 1 and 2. Conclusions: Intravesical therapy with combination of mitomycin-C and chemohyperthermia seems to be appropriate in high-risk patients with non-muscle-invasive bladder cancer who cannot tolerate or have contraindications for standard BCG therapy.

A Potential-Based Panel Method for the Analysis of Resistance Characteristics of a High Speed Catamaran (포텐셜기저 패널법에 의한 고속쌍동선의 저항성능 해석)

  • Kim, Y.G.;Rhyu, S.S.;Yoo, J.H.;Lew, J.M.;Hong, S.K.
    • Journal of the Society of Naval Architects of Korea
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    • v.34 no.4
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    • pp.12-20
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    • 1997
  • A potential-based panel method has been developed to investigate the resistance characteristics of a high speed catamaran advancing on the free surface. Normal dipoles and sources are distributed on the body surface while sources are distributed on the free surface. Linearised free surface conditions are used in the present analysis. To avoid the instabilities due to the velocity difference between inner and outer flow of a high speed catamaran, Kutta condition has been applied at the stern. Model test has been carried out not only to validate the numerical results but to confirm the capabilities of a CWC(Circulating Water Channel). It is believed that we can obtain the qualitatively reasonable results in the CWC. Computed results are compared with those of experiments and Insel's experimental values. Since the Kutta condition is applied at the stern, stable solutions are obtained at the high speed range. The present method, using linearised free surface conditions at the high speed range, seems to be a useful tool in the hull form design of a high speed catamaran.

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Clinical Outcome of Endoscopic Procedure in Patients with Shunt Malfunction

  • Kyung Hyun Kim;Youngbo Shim;Ji Yeoun Lee;Ji Hoon Phi;Eun Jung Koh;Seung-Ki Kim
    • Journal of Korean Neurosurgical Society
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    • v.66 no.2
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    • pp.162-171
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    • 2023
  • Objective : The goal of this study was to analyze the clinical outcomes of endoscopic third ventriculostomy (ETV) and endoscopic septostomy when shunt malfunction occurs in a patient who has previously undergone placement of a ventriculoperitoneal shunt. Methods : From 2001 to 2020 at Seoul National University Children's Hospital, patients who underwent ETV or endoscopic septostomy for shunt malfunction were retrospectively analyzed. Initial diagnosis (etiology of hydrocephalus), age at first shunt insertion, age at endoscopic procedure, magnetic resonance or computed tomography image, subsequent shunting data, and follow-up period were included. Results : Thirty-six patients were included in this retrospective study. Twenty-nine patients, 18 males and 11 females, with shunt malfunction underwent ETV. At the time of shunting, the age ranged from 1 day to 15.4 years (mean, 2.4 years). The mean age at the time of ETV was 13.1 years (range, 0.7 to 29.6 years). Nineteen patients remained shunt revision free. The 5-year shunt revision-free survival rate was 69% (95% confidence interval [CI], 0.54-0.88). Seven patients, three males and four females, with shunt malfunction underwent endoscopic septostomy. At the time of shunting, the age ranged from 0.2 to 12 years (mean, 3.9 years). The mean age at the time of endoscopic septostomy was 11.9 years (range, 0.5 to 29.5 years). Four patients remained free of shunt revision or addition. The 5-year shunt revision-free survival rate was 57% (95% CI, 0.3-1.0). There were no complications associated with the endoscopic procedures. Conclusion : The results of our study demonstrate that ETV or endoscopic septostomy can be effective and safe in patients with shunt malfunction.

Effect of Free Surface Based on Submergence Depth of Underwater Vehicle

  • Youn, Taek-Geun;Kim, Min-Jae;Kim, Moon-Chan;Kang, Jin-Gu
    • Journal of Ocean Engineering and Technology
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    • v.36 no.2
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    • pp.83-90
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    • 2022
  • This paper presents the minimum submergence depth of an underwater vehicle that can remove the effect of free surface on the resistance of the underwater vehicle. The total resistance of the underwater vehicle in fully submerged modes comprises only viscous pressure and friction resistances, and no wave resistance should be present, based on the free surface effect. In a model test performed in this study, the resistance is measured in the range of 2 to 10 kn (1.03-5.14 m/s) under depth conditions of 850 mm (2.6D) and 1250 mm (3.8D), respectively, and the residual resistance coefficients are compared. Subsequently, resistance analysis is performed via computational fluid dynamics (CFD) simulation to investigate the free surface effect based on various submergence depths. First, the numerical analysis results in the absence of free surface conditions and the model test results are compared to show the tendency of the resistance coefficients and the reliability of the CFD simulation results. Subsequently, numerical analysis results of submergence depth presented in a reference paper are compared with the model test results. These two sets of results confirm that the resistance increased due to the free surface effect as the high speed and depth approach the free surface. Therefore, to identify a fully submerged depth that is not affected by the free surface effect, case studies for various depths are conducted via numerical analysis, and a correlation for the fully submerged depth based on the Froude number of an underwater vehicle is derived.

A Study on Certification Method of Health and Barrier Free Environment by the BIM for Aged Person - With Sanitary Facilities of Elderly Housing Facility - (노인 주거시설의 위생공간을 중심으로 고령자의 건강과 무장애 생활환경을 위한 인증 방법에 관한 연구 - BIM기반 설계 및 응용을 통한 방법을 중심으로 -)

  • Hong, Sa-Chul;Paik, Jin-Kyung;Kim, Suk-Tae
    • Korean Institute of Interior Design Journal
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    • v.26 no.3
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    • pp.13-24
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    • 2017
  • Promoting barrier-free living environments is necessary in residential facilities on which senior citizens rely most of their lives. Safety of elder people can be reassured by a certification system based on the existing barrier-free certification program in public facilities. The range of certification does not cover all living area, but is limited to the bathroom, which is a sanitary space. Given the nature of BIM modeling, an existing multi-family building was selected and modeled, as the certification process requires all the necessary information and various viewport. BIM modeling of the bathroom was conducted in accordance with the requirements of the certification for barrier-free living environment. The results suggested that there is a need for a removal of thresholds, larger doors, better selection of finishing materials, sufficient room for a wheelchair, larger space next to the toilet, and the availability of an emergency bell and grab bars. Such information supports the potentials of BIM modeling, and it is expected that an automated certification system would be established in the foreseeable future.

Damage Assessment of Free-fall Dropped Object on Sub-seabed in Offshore Operation

  • Won, Jonghwa;Kim, Youngho;Park, Jong-Sik;Kang, Hyo-dong;Joo, YoungSeok;Ryu, Mincheol
    • Journal of Advanced Research in Ocean Engineering
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    • v.1 no.4
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    • pp.198-210
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    • 2015
  • This paper presents the damage assessment of a free-fall dropped object on the seabed. The damage to a dropped object totally depends on the relationship between the impact energy and the soil strength at the mudline. In this study, unexpected dropping scenarios were first assumed by varying the relevant range of the impact velocity, structure geometry at the moment of impact, and soil strength profile along the penetration depth. Theoretical damage assessments were then undertaken for a free-fall dropping event with a fixed final embedment depth for the structure. This paper also describes the results of a three-dimensional large deformation finite element analysis undertaken for the purpose of validation. The analyses were carried out using the coupled Eulerian-Lagrangian approach, modifying the simple elastic-perfectly plastic Tresca soil model. The validation exercises for each dropping scenario showed good agreement, and the present numerical approach was capable of predicting the behavior of a free-fall dropped object.

Analysis of Performance on Asymmetric LED Lens Design Using Three-Dimensional Free-Form Surface Expression (3차원 자유곡면식을 이용한 LED 비대칭 렌즈 설계 및 성능 비교 분석)

  • Lee, Chang Soo;Lee, Soo Young;Hyun, Dong Hoon
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.26 no.3
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    • pp.328-336
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    • 2017
  • The exit surface of a lens is designed using a three-dimensional free-form expression in order to easily modify a curved surface. This enables the design of numerical values and mathematical things using three-dimensional free-form expression, and enhances precision because it can be fine-tuned via numerical control. The standard of "Classification of Luminaire Light Distribution" for outdoor lighting fixtures by IESNA is adopted in order to examine the correlation between three-dimensional free-form surface expression and lighting performance. The variation of light distribution type and range is analyzed using the values of maximum light intensity and 50% light intensity. The actual tolerance occurs owing to parameters such as the thickness of the lens, the distance between LEDs, and the movement of the center of the incident surface; the effects of changes in these parameters on the performance are compared and analyzed.

A method of minimum-time trajectory planning ensuring collision-free motion for two robot arms

  • Lee, Jihong;Bien, Zeungnam
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10b
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    • pp.990-995
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    • 1990
  • A minimum-time trajectory planning for two robot arms with designated paths and coordination is proposed. The problem considered in this paper is a subproblem of hierarchically decomposed trajectory planning approach for multiple robots : i) path planning, ii) coordination planning, iii) velocity planning. In coordination planning stage, coordination space, a specific form of configuration space, is constructed to determine collision region and collision-free region, and a collision-free coordination curve (CFCC) passing collision-free region is selected. In velocity planning stage, normal dynamic equations of the robots, described by joint angles, velocities and accelerations, are converted into simpler forms which are described by traveling distance along collision-free coordination curve. By utilizing maximum allowable torques and joint velocity limits, admissible range of velocity and acceleration along CFCC is derived, and a minimum-time velocity planning is calculated in phase plane. Also the planning algorithm itself is converted to simple numerical iterative calculation form based on the concept of neural optimization network, which gives a feasible approximate solution to this planning problem. To show the usefulness of proposed method, an example of trajectory planning for 2 SCARA type robots in common workspace is illustrated.

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Comparative Free and Acetylated Polyamine Profiles in the Urine of Normal Subjects and Various Cancer Patients

  • Suh, Ja Won;Lee, Seon Hwa;Park, Young Han;Chung, Bong Chul;Park, Jongsei
    • Analytical Science and Technology
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    • v.8 no.4
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    • pp.895-900
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    • 1995
  • Urinary free and acetylated polyamine profiles have been investigated for their potential usefulness as biochemical markers of cancer in a control of group comprised of healthy volunteers (32 cases) and patients with various types of cancers(48 cases). The nine (5 free and 4 acetylated) endogeneous polyamines were simultaneously determined by a sensitive capillary gas chromatography/nitrogen-phosphorus detector (GC/NPD). The newly modified (simple and convenient) method was developed and the compounds were isolated by adsorption onto silica gel and derivatized by heptafluorobutyric anhydride to enhance their specificity on gas chromatograms. The good quality-control data were obtained through the precision and accuracy test and the recovery range of them was 48.6 ~ 101.2 %. The Korean reference values of urinary polyamines were established and significant differences were found in cancer patients compared with normal subjects. Also, to eliminate subject variations, precursors to product concentration ratios were compared between cancer patients and control group. The ratios of both putrescine to spermidine and total (free plus acetylated) putrescine to total spermidine were significantly greater in cancer patients than in normal subjects.

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