Measuring Receptor/Ligand Interaction at the Single-Bond Level: Experimental and Interpretative Issues

There is increased interest in measuring kinetic rates, lifetimes, and rupture forces of single receptor/ligand bonds. Valuable insights have been obtained from previous experiments attempting such measurements. However, it remains difficult to know with sufficient certainty that single bonds were indeed measured. Using exemplifying data, evidence supporting single-bond observation is examined and caveats in the experimental design and data interpretation are identified. Critical issues preventing definitive proof and disproof of single-bond observation include complex binding schemes, multimeric interactions, clustering, and heterogeneous surfaces. It is concluded that no single criterion is sufficient to ensure that single bonds are actually observed. However, a cumulative body of evidence may provide reasonable confidence. 0 2002 Biomedical Engineering Society.

Researches on essential mechanics issues for submerged floating tunnel

Since 2001, a research group in the Institute of Mechanics, Chinese Academy of Sciences, has been devoted to the research of essential mechanics issues for submerged floating tunnel (SFT). In addition to the structural design of the SFT prototype in Qiandao Lake, the relevant researches cover a number of topics. This paper briefly describes the research procedure and results, including dynamic response of SFT due to surface wave, vortex-induced vibration of anchoring system, structural analysis of curved SFT, temperature effects of curved SFT, structural dynamic response due to accidental load, and effects of structural parameters (buoyancy-weight ratio, tunnel length，tether stiffness，etc.) on dynamic response.

Some engineering issues of an FBG sensor with the dual gratings parallel matched interrogation method

The key issues of engineering application of the dual gratings parallel matched interrogation method are expanding the measurable range, improving the usability, and lowering the cost by adopting a compact and simple setup based on existing conditions and improving the precision of the data-processing scheme. A credible and effective data-processing scheme based on a novel divisional look-up table is proposed based on the advantages of other schemes. Any undetermined data is belonged to a certain section, which can be confirmed at first, then it can be looked up in the table to correspond to microstrain by the scheme. It not only solves inherent problems of the traditional one (double value and small measurable range) but also enhances the precision, which improves the performance of the system. From the experimental results, the measurable range of the system is 525 mu epsilon, and the precision is +/- 1 mu epsilon based on normal matched gratings. The system works in real time, which is competent for most engineering measurement requirements. (C) 2007 Elsevier GmbH. All rights reserved.

The Yangtze River dolphin or baiji (Lipotes vexillifer): population status and conservation issues in the Yangtze River, China

1. Baiji were sighted 17 times during three recent simultaneous multi-vessel surveys in the Yangtze River, China (November 4-10, 1997; December 4-9, 1998; October 31-November 5, 1999). There were 11 sightings in 1997 (consisting of 17 animals), five in 1998 (seven animals), and two in 1999 (four animals). It was concluded that 13 individuals Could be considered as a minimum number of the baiji currently in the Yangtze River. 2. An annual rate of population decrease was roughly estimated as 10%. From the body sizes observed, the proportions of old, adult and immature individuals were approximately estimated at 57, 26, and 17% respectively. 3. Baiji showed a significant attraction to confluences and sand bars with large eddies. The present distribution range of the baiji is less than 1400 km in length in the Yangtze main river. Distances between the two nearest groups of baiji appear to be increasing. 4. Two typical sightings are described, in which surfacing and movements of baiji were recorded. Baiji were often found swimming together with finless porpoise. In the surveys they occurred in the same group in 63% of occurrences. Interactions between baiji and finless porpoise are described and discussed. 5. Human activities are the main threats to the baiji. Illegal electrical fishing accounted for 40% of known mortalities during the 1990s. Engineering explosions for maintaining navigation channels have become another main cause of baiji deaths. The last hope of saving the species may be to translocate the remaining baiji into a semi-captive reserve. known as the 'Baiji Semi-natural Reserve'. Copyright (C) 2003 John Wiley Sons, Ltd.

Morphological defects and uniformity issues of 4H-SiC homoepitaxial layers grown on off-oriented (0001)Si faces

The morphological defects and uniformity of 4H-SiC epilayers grown by hot wall CVD at 1500 degrees C on off-oriented (0001) Si faces are characterized by atomic force microscope, Nomarski optical microscopy, and Micro-Raman spectroscopy. Typical morphological defects including triangular defects, wavy steps, round pits, and groove defects are observed in mirror-like SiC epilayers. The preparation of the substrate surface is necessary for the growth of high-quality 4H-SiC epitaxial layers with low-surface defect density under optimized growth conditions. (c) 2006 Elsevier Ltd. All rights reserved.

Morphological defects and uniformity issues of 4H-SiC homoepitaxial layers grown on off-oriented (0001)Si faces

The morphological defects and uniformity of 4H-SiC epilayers grown by hot wall CVD at 1500 degrees C on off-oriented (0001) Si faces are characterized by atomic force microscope, Nomarski optical microscopy, and Micro-Raman spectroscopy. Typical morphological defects including triangular defects, wavy steps, round pits, and groove defects are observed in mirror-like SiC epilayers. The preparation of the substrate surface is necessary for the growth of high-quality 4H-SiC epitaxial layers with low-surface defect density under optimized growth conditions. (c) 2006 Elsevier Ltd. All rights reserved.

Assessment of coastal zone sustainable development: A case study of Yantai, China

The assessment of sustainable development is a challenging task as its measuring is rather complex without a mature framework. In this paper, as a case study, a coastal city of China-Yantai was assessed for sustainable development in the period from 1998 to 2007. We used a methodological framework based on 36 indicators and three composite indices from the dimensions of environment, economy and society subsystems. The assessment results indicated that Yantai was almost in the potentially unsustainable development or intermediate sustainable development, except in 1998 and in 2007. Accordingly, the progress of sustainable development was divided into two stages in the light of the relative changes of three subsystems. Some relevant issues, such as natural capital, GPI vs. GDP in sustainable development assessment were discussed. Finally, an uncertainty analysis was also given in the assessment. In conclusion, the sustainable development in Yantai had experienced a shift from environment-based to social-economic-based in the past 10 years. (C) 2010 Elsevier Ltd. All rights reserved.