Eleven A-ring modified hexacyclic analogues of camptothecin (CPT) containing a 1,4-oxazine ring were synthesized from 10-hydroxycamptothecin (11a) and 7-ethyl-10-hydroxycamptothecin (3) (SN-38) in four to five steps and were subjected to the biological tests such as cytotoxicity, topoisomerase I (Topo I) inhibitory activity, acetylcholinesterase (AChE) inhibition, and stability in human plasma. Four compounds 15a, 15b, 16a, and 16c were about 2-fold more potent than topotecan and as potent as CPT toward human cancer cell lines A549, H128, WiDr, MKN45, SK-OV-3, and SK-BR-3 in vitro, even though the most active compound 15b was slightly less potent than SN-38. The potency of Topo I inhibition of these compounds showed relatively good correlation with their cytotoxicity. Most of the compounds exhibited AChE inhibitory activity weaker (9 +/- 2 to 20 +/- 3%) than CPT (23 +/- 5%) or topotecan (20 +/- 4%) and similar to SN-38 (13 +/- 2%), indicating that they might have little effect on causing early diarrhea. The stability of lactone forms of these compounds in human plasma seemed to be much higher than that of CPT and similar to that of topotecan but lower than that of SN-38. Among the new hexacyclic CPT analogues, compound 15b showed higher antitumor activity against human tumor xenograft, WiDr, in nude mice compared to that of SN-38. The most promising compound 15b has been selected for further development.

Dean's equilibrium beach profile formula was used to investigate the correlation between the static shoreline position and the incident wave energy. The effect of the longshore sediment transport was neglected, and the results showed the reasonable agreement compared with the field observations of Yates et al.(2009)

No abstract

Recently, the impacts of short-term erosion caused by storm waves on coastal damages are increasingly recognized as social issues, compared to those of long-term erosion from climate change or coastal development. The erosion caused by the storm wave has an episodic characteristic that the shoreline recovers gradually after retreating for a short-term. Furthermore, if shoreline changes caused by longshore sediment transport are not taken into consideration, the shoreline position is determined by following two physical parameters based on the bulk response model. The beach response factor determines converging ultimate erosion on the assumption that incident waves constantly affects a beach, which can be estimated according to the concept of Dean’s profile. On the contrary, the beach recovery factor affects the velocity of the shoreline retreat and recovery. Therefore, the parameter plays an important role to predict the peak erosion due to the storms. However, there are still insufficient researches to utilize it as an engineering design for erosion reduction. In this study, the two methodologies (i.e., approximation formula and statistical analysis) that estimates peak erosion width caused by the storms are compared to extract the beach recovery factor. During the process, it is confirmed that peak wave height has little impact on the beach recovery factor. Instead, it is mainly determined by the median grain size. Also, the beach recovery factor is estimated as a function of median grain size based on the shoreline and sand survey data conducted over ten years. Among the 41 surveyed sites along the east coast, 11 sites of straight-type shorelines that directly react to the incident waves were applied to consider only the short-term recovery process. To prove validity, the estimated applied into the real sea and then the results were compared to the shoreline data extracted from CCTV images. Using these results, the peak erosion width for a target wave event can be predicted with only median grain size. These study results are expected to be used as a concrete and practical means to manage the coast, in preparation for the current and future shoreline erosion threats.

In this paper, we perform a complexity analysis for implementation of the ISO/IEEE 11073 Personal Health Device (PHD) standards in order to check the required system resources when ISO/IEEE 11073 PHD standards are implemented on the embedded system. Base on the implemented programs complying the PHD standards for a weighing scale, a blood pressure monitor, and a glucose meter among the various personal health devices, we make a pseudo-code. And then from the two different points of view such as program memory space and data memory space, we make a complexity analysis model. Because system resources or capability are strongly restricted in the personal health devices, our research work is very useful to estimate the required system resources.* ㈜유헬스넷