Antiproliferative and apoptosis-inducing potential of 3β-hydroxy-△5-steroidal congeners purified from the soft coral Dendronephthya putteri

The exploration and identification of antiproliferative phytochemicals have received increased attention in medicinal chemistry.In particular,research focused on the toxicology of marine natural products has increased in recent years.Terpenoids,among many secondary metabolites,have been demonstrated to act as effective anticancer agents.Soft corals,a group of marine invertebrates,produce a variety of terpenoids with biofunctional properties.The current study presents the extraction,purification,and identification of sterol congeners from the soft coral Dendronephthya putteri.The method involves 50%chloro form-methanol extraction,polar column fractionation,and analy sis through GC-MS~n.Do se-dependent antiproliferative activity was observed within the sterol-rich fraction(DPCMH 2-4),which consisted of3β-hydroxy-A5-steroidal congeners.This fraction inhibited the growth of HL-60 and MCF-7 cells with IC_(50) values of 25.27±1.43 and 22.81±0.15 μg/mL,respectively.Apoptotic body formation,DNA damage,cell cycle arrest,and apoptotic cell signaling pathway activation were also observed,reinforcing the dosedependent antiproliferative and apoptosis-inducing activity of 3β-hydroxy-A5-steroidal congeners.To our knowledge,this is the first report of anticancer agent identification from the soft coral D.putteri.Based on the observations,these steroidal congeners are promising candidates for the development of anticancer drugs.     

Extraction of real modes and physical matrices from modal testing

A technique to extract real modes from the identified complex modes is presented in this paper, which enables the normalized real mode shapes, modal masses, and full or reduced mass and stiffness matrices to be obtained. The theoretical derivation of the method is provided in detail. An 11-DOF vibration system is used to validate the algorithm, and to analyze the effects of the number of modes utilized and measurement DOFs on the extraction results. Finally, the method is used to extract real modes from both experimental modal analysis and operational modal analysis.     

Extraction of real modes and physical matrices from modal testing

A technique to extract real modes from the identifi ed complex modes is presented in this paper, which enables the normalized real mode shapes, modal masses, and full or reduced mass and stiffness matrices to be obtained. The theoretical derivation of the method is provided in detail. An 11-DOF vibration system is used to validate the algorithm, and to analyze the effects of the number of modes utilized and measurement DOFs on the extraction results. Finally, the method is used to extract real modes from bo...     

Reprising the role of the developmental state in cluster development: The biomedical industry in Singapore

This paper broadly sketches the initiation of a biomedical industry cluster in Singapore and how it is driven in a knowledge-based economy. Specifically, we reprise the role of the developmental state in spearheading cluster development, and by so doing critique the prevailing view that rejects the involvement of industrial policy and the state beyond that of just a facilitator in cluster development. Drawing from a modest survey and interview sampling supplemented with secondary data we illustrate how the Singapore city-state is not passive but instead plays an active role as a cluster creator in moving towards a knowledge-based economy.     

Substructural first‐ and second‐order model identification for structural damage assessment

This paper presents two methods to perform system identification at the substructural level, taking advantage of reduction in the number of unknowns and degrees of freedom (DOFs) involved, for damage assessment of fairly large structures. The first method is based on first‐order state space formulation of the substructure where the eigensystem realization algorithm (ERA) and the observer/Kalman filter identification (OKID) are used. Identification at the global level is then performed to obtain the second‐order model parameters. In the second method, identification is performed at the substructural level in both the first‐ and second‐order model identification. Both methods are illustrated using numerical simulation studies where results indicate their significantly better performance than identification using the global structure, in terms of efficiency and accuracy. A 12‐DOF system and a fairly large structural system with 50 DOFs are used where the effects of noisy data are considered. In addition to numerical simulation studies, laboratory experiments involving an eight‐storey frame model are carried out to illustrate the performance of the proposed method. The identification results presented in terms of the stiffness integrity index show that the proposed methodology is able to locate and quantify damage fairly accurately. Copyright © 2005 John Wiley & Sons, Ltd.