Anticlastogenic Effects of Galangin against N-Methyl-N'-nitro-N-nitrosoguanidine-induced Micronuclei in Bone-marrow CElls of C57BL/6 Mice

Heo, Moon Young,Sohn, Dong Hun,Kim, Kyeong Ho,Lee, Su Jun,Kwon, Chang Ho,William W. Au4 한국응용약물학회 1993 Biomolecules & Therapeutics(구 응용약물학회지) Vol.1 No.2

The anticlastogenic effect of galangin, flavonoid derivative, was studied in vivo micronucleus test using C57BL/6 mice. The frequencies of micronuclei induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in bone-marrow cells of C57BL/6 mice were significantly decreased by the simultaneous treatment or multiple pre-treatment of galangin. When galangin was orally administered at 0, 0.1, 1.0, or 10.0 mg/kg twice with 24 hr interval, together with intraperitoneally administered MNNG, there were suppressive effects in the tested doses. The most marked suppressive effect was observed in the treatment group of 1.0 mg/kg (64.5%), not in the treatment group of 10.0 mg/kg (36.3%). When galangin was multiply administered at 1/7 or 1 mg/kg for 7 days respectively, galangin showed higher suppressive effect in the treatment group of 1/7 mg/kg (23.5%) rather than in the treatment group of 1 mg/kg (13.5%). In another experiment, galangin was administered at 0.001, 0.01 or 0.1 mg/kg for 1 month respectively. The suppressive effects in one month treatment gradually increased with dose-dependent manner, although suppressive effects were not high. The results showed that galangin was effective in suppressing the frequencies of micronuclei induced by MNNG. Our study indicates that galangin is a potent anticlastogenic agent against MNNG.

Effect of wing corrugation on aerodynamic performance in 3D flapping wings

Au Thi Kim Loan(아우티킴론),Nguyen Khanh(유엔 칸),Soo Hyung Park(박수형),Hoon Cheol Park(박훈철) 한국항공우주학회 2019 한국항공우주학회 학술발표회 논문집 Vol.2019 No.11

An Exposition and Evaluation of Whitehead's Philosophical Theology : Part Ⅱ: The Whiteheadean Epistemology

Au, Peter Ying-Yuk Asian Center for Theological Studies and Mission 1988 ACTS 신학저널 Vol.3 No.-

A.N. Whitehead's metaphysics and epistemology cannot be separated. His metaphysics is an attempt to describe all of life's experience. It is a description or a science which "seeks to discover the general ideas which are indispensably relevant to the analysis of everything that happens (Italics mine)" (RM, 82). Hence his metaphysics presupposes his epistemology, and likewise, his epistemology presupposes his metaphysics. Both are mutually dependent. His epistemology, simply stated, is the doctrine of "experience" which correlates t o his metaphysics as the doctrine of ''process." Whitehead expresses it succintly, "we experience the universe, and we analyse in our con- sciousness a minute selection of its details" (MT, 121). The business of metaphysics is then, by a conscious effort to formulate its character, this totality, the universe. From this totality, namely the universe, the operations of conscious awareness, of language, of scientific identification and description, have made their selective emphases. Therefore, having understood Whitehead's metaphysics, we shall attempt to grasp that which he claims to have experienced and that which he comes to know as the totality of life.

Ambient Vibration measurements and finite element modelling for the Hong Kong Ting Kau Bridge

Au, F.T.K.,Tham, L.G.,Lee, P.K.K.,Su, C.,Han, D.J.,Yan, Q.S.,Wong, K.Y. Techno-Press 2003 Structural Engineering and Mechanics, An Int'l Jou Vol.15 No.1

The Ting Kau Bridge in Hong Kong is a cable-stayed bridge comprising two main spans and two side spans. The bridge deck is supported by three towers, an end pier and an abutment. Each of the three towers consists of a single reinforced concrete mast which reduces its section in steps, and it is strengthened by transverse cables and struts in the transverse vertical plane. The bridge deck is supported by four inclined planes of cables emanating from anchorages at the tower tops. In view of the threat from typhoons, the dynamic behaviour of long-span cable-supported bridges in the region is always an important consideration in their design. This paper is devoted to the ambient vibration measurements of the bridge for evaluation of dynamic characteristics including the natural frequencies and mode shapes. It also describes the modelling of the bridge. A few finite element models are developed and calibrated to match with the field data and the results of subsequent structural health monitoring of the bridge.

Chronic myeloid leukemia in Asia

Au, Wing Y.,Caguioa, Priscilla B.,Chuah, Charles,Hsu, Szu Chun,Jootar, Saengsuree,Kim, Dong-Wook,Kweon, Il-Young,O’Neil, William M.,Saikia, Tapan K.,Wang, Jianxiang Springer-Verlag 2009 INTERNATIONAL JOURNAL OF HEMATOLOGY Vol.89 No.1

Comparison of Aerodynamic Forces and Moments Calculated by Three-dimensional Unsteady Blade Element Theory and Computational Fluid Dynamics

Au, Loan Thi Kim,Phan, Hoang Vu,Park, Hoon Cheol Elsevier Science B.V., Amsterdam 2017 JOURNAL OF BIONICS ENGINEERING Vol.14 No.4

<P>In previous work, we modified blade element theory by implementing three-dimensional wing kinematics and modeled the unsteady aerodynamic effects by adding the added mass and rotational forces. This method is referred to as Unsteady Blade Element Theory (UBET). A comparison between UBET and Computational Fluid Dynamics (CFD) for flapping wings with high flapping frequencies (> 30 Hz) could not be found in literature survey. In this paper, UBET that considers the movement of pressure center in pitching-moment estimation was validated using the CFD method. We investigated three three-dimensional (3D) wing kinematics that produce negative, zero, and positive aerodynamic pitching moments. For all cases, the instantaneous aerodynamic forces and pitching moments estimated via UBET and CFD showed similar trends. The differences in average vertical forces and pitching moments about the center of gravity were about 10% and 12%, respectively. Therefore, UBET is proven to reasonably estimate the aerodynamic forces and pitching moment for flight dynamic study of FW-MAV. However, the differences in average wing drags and pitching moments about the feather axis were more than 20%. Since study of aerodynamic power requires reasonable estimation of wing drag and pitching moment about the feather axis, UBET needs further improvement for higher accuracy.</P>

An Exposition and Evaluation of Whitehead's Philosophical Theology : An evangelical response to process theology

Au, Peter Ying-Yuk Asian Center for Theological Studies and Mission 1986 ACTS 신학저널 Vol.2 No.-

Since the discovery of the quantum mechanics, magnetic and gravitational field theory, Darwin's evolutionary theory, Einstein's theory of relativity, the submolecular vibration and the superconductivity of the near-absolute zero temperature, the traditional Newtonian reality has been shattered. Reality is no longer considered as static corpuscular atoms bound by absolute space and time. These modern ecientific discoveries undermine the entier philosophy of science to account for the nature of things as they perceived it. Consequently, a new metaphysics is necessary to account for the modern science, human moral and religious experiences. Alfred North Whitehead was born at the opportune time to capture the desire of the age and apply the theories of the modern physics to the realm of reality. Thus he becomes and epitome of the inquiry into a new metaphysics. His discovery has a far-reaching implication in the areas of science, philosophy and religion. No scientist, philosopher and tehologian can afford to bypass Whitehead's metaphysics too lightly. whitehead's metaphysics openly challenges the theistic metaphysics and redefines the metaphysical attributes of God. The classical theistic metaphysical attributes of God are aseity, necessity, simplicity, infinity, eternity, purity, and unity. The classical theist conceives God as the necessary being which is uncaused and self-existing(aseity). Everything else in the world is a contingent being dependent upon this necessary being for its existence. Being necessary, God must be also a pure actuality without any potentiality to change. Likewise pure actuality has no parts or principle of division within Him, or He is a simple being. Similarly, he must be non-temporal and non-spatial, for time and space involve some kind of change. Furthermore, a pure actuality is unlimited, for potentiality is the principle of limitation. He must be eternal and infinite. All of the above metaphysical attributes of God are repudiated by the Whiteheadean metaphysics. In other words, the Whiteheadean metaphysics poses a serious challenge to the basic doctrine of orthodox faith, the doctrine of God. This study is an attempt to interact with the Whiteheadean metaphysics and epistemology. The purpose is to understand the system and be able to state it clearly and accurately. Having given the exposition of the system, the author will evaluate and citique it. First of all, we shall look into the development of the Whiteheaden metaphysics in its historical context.

Stochastic control approach to reliability of elasto-plastic structures

Au, Siu-Kui Techno-Press 2009 Structural Engineering and Mechanics, An Int'l Jou Vol.32 No.1

An importance sampling method is presented for computing the first passage probability of elasto-plastic structures under stochastic excitations. The importance sampling distribution corresponds to shifting the mean of the excitation to an 'adapted' stochastic process whose future is determined based on information only up to the present. A stochastic control approach is adopted for designing the adapted process. The optimal control law is determined by a control potential, which satisfies the Bellman's equation, a nonlinear partial differential equation on the response state-space. Numerical results for a single-degree-of freedom elasto-plastic structure shows that the proposed method leads to significant improvement in variance reduction over importance sampling using design points reported recently.

Cytogenetic assays for monitoring populations exposed to environmental mutagens

Au, William W. 강원대학교 종합약학연구소 2001 약학연구 Vol.13 No.-

Time-dependent effects on dynamic properties of cable-stayed bridges

Au, Francis T.K.,Si, X.T. Techno-Press 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.41 No.1

Structural health monitoring systems are often installed on bridges to provide assessments of the need for structural maintenance and repair. Damage or deterioration may be detected by observation of changes in bridge characteristics evaluated from measured structural responses. However, construction materials such as concrete and steel cables exhibit certain time-dependent behaviour, which also results in changes in structural characteristics. If these are not accounted for properly, false alarms may arise. This paper proposes a systematic and efficient method to study the time-dependent effects on the dynamic properties of cable-stayed bridges. After establishing the finite element model of a cable-stayed bridge taking into account geometric nonlinearities and time-dependent behaviour, long-term time-dependent analysis is carried out by time integration. Then the dynamic properties of the bridge after a certain period can be obtained. The effects of time-dependent behaviour of construction materials on the dynamic properties of typical cable-stayed bridges are investigated in detail.