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Sunagar SG Lakkappan VJ Ingalhalli SS Savanurmath CJ Hinchigeri SB 《Photochemistry and photobiology》2008,84(6):1440-1444
Multiple forms of red fluorescent proteins (RFPs) were observed in the gut juice of the silkworm, Bombyx mori L. It is to be noted that only one RFP band is reported in the literature so far. However, we report here three electrophoretically separated RFPs (A, B and C) found to be heterogeneous with respect to their components, namely the protein part and the fluorescent tetrapyrrole pigment moiety. Of the three RFPs, band C was found to be a glycoprotein. The absorption extinction coefficients and fluorescence quantum yields of the three RFPs were estimated. Further, this is the first communication demonstrating the presence of three different chlorophyll derivatives associated with the three different RFPs. The pigments were analyzed by thin layer chromatography followed by their elution to characterize the pigments by spectrophotometric and spectrofluorometric methods. Spectral characteristics have led to the identification of monovinyl chlorophyllide a, divinyl protochlorophyllide a and monovinyl pheophytin a as being associated with RFP bands A, B and C, respectively. These three purified RFPs can serve as the source of the three pigments as the standards. 相似文献
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Wagener M van Geerestein VJ 《Journal of chemical information and computer sciences》2000,40(2):280-292
Using decision trees, a model to discriminate between potential drugs and nondrugs has been developed. Compounds from the Available Chemical Directory and the World Drug Index databases were used as training set; the molecular structures were represented using extended atom types. The error rate on an independent validation data set is 17.4%. The number of false negatives can be reduced by penalizing the misclassification of drugs so that 92 out of 100 potential drugs are correctly recognized. At the same time, 34 out of 100 nondrugs are classified as potential drugs. The predictions of the model can be used to guide the purchase or selection of compounds for biological screening or the design of combinatorial libraries. The visualization of the generated models in the form of colored trees allowed us to identify a few, surprisingly simple features that explain the most significant differences between drugs and nondrugs in the training set: Just by testing the presence of hydroxyl, tertiary or secondary amino, carboxyl, phenol, or enol groups, already three quarters of all drugs could be correctly recognized. The nondrugs, on the other hand, are characterized by their aromatic nature with a low content of functional groups besides halogens. The general applicability of the model is shown by the predictions made for several Organon databases. 相似文献
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Feiyang Wu Logeeswaran VJ M. Saif Islam David A. Horsley Robert G. Walmsley Sagi Mathai Denny Houng Michael R. T. Tan Shih-Yuan Wang 《Applied Physics A: Materials Science & Processing》2009,95(4):1079-1088
In many computer and server communications copper cables and wires are currently being used for data transmission and interconnects.
However, due to significant shortcomings, such as long transmission time, high noise level, unstable electrical properties,
and high power consumption for cooling, researchers are increasingly turning their research interests toward alternatives,
such as fiber optic interconnects and free-space optical communication technologies. In this paper, we present design considerations
for an integrated receiver for high-speed free-space line-of-sight optical interconnects for distortion-free data transmission
in an environment with mechanical vibrations and air turbulences. The receiver consists of an array of high-speed photodiodes
for data communication and an array of quadrant photodiodes for real-time beam tracking in order to compensate for the beam
misalignment caused by vibrations in servers. Different configurations for spatially positioning the quadrant and data photodiodes
are discussed for 4×4 and 9×9 multielement optical detector arrays. We also introduce a new beam tracking device, termed the
strip quadrant photodiodes, in order to accurately track highly focused optical beams with very small beam diameter. 相似文献
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We report a novel digital-deflection programmable micromirror array driven by micromechanical digital-to-analog converters that eliminates the need for electrical digital-to-analog converters for analog displacement control, thus simplifying the driving circuitry and reducing the overall system cost. Furthermore, owing to the bistable and hysteretic characteristics of parallel-plate electrostatic actuators, an array of micromirrors can be controlled by means of row- and column-addressing lines, which drastically reduce the number of routing wires and allow array sizes to increase while they maintain high array quality. 相似文献
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