Target-triggered hairpin-free chain-branching growth of DNA dendrimers for contrast-enhanced imaging in living cells by avoiding signal dispersion

The development of amplification strategies is one of the central challenges for detection of lowabundance targets. One-to-many(1:M) amplification strategies in which one target lights many signal probes, has improved the detection sensitivity in bulk solution, but with discounted contrast in cell imaging, because the lighted probes are dissociative and dispersible. In this work, a one-to-large(1:L) signaling mechanism, in which the lighted probes were orderly connected to each other, was conceptually proposed to enhance the contrast in cell imaging by avoiding signal dispersion in amplification. Accordingly,target-triggered hairpin-free chain-branching assembly(HFCBA) holds great potential to implement the1:L mechanism, but using it in cell imaging has yet to be demonstrated. As a proof of concept, a group of probes were first programmed to implement mi RNA-21-triggered HFCBA. After transfection of probes,gradually-growing signal flares in cells were monitored along with the growth of DNA dendrimers;and the in situ fluorescence accumulation in HFCBA resulted in highly-enhanced contrast to the surrounding by avoiding signal dispersion in amplification. The contrast-enhanced imaging with signal amplification is significant for biological analysis and molecular medicine. We expect the 1:L mechanism will provide a new thought for high-performance imaging of biomarkers in cells.

Directly Modulated 10 Gb/s Signal Transmission over 320 km of Negative Dispersion Fiber for Regional Metro Network

We demonstrate the transmission of directly modulated 10-Gb/s WDM signals over 320 km of negative dispersion fiber (dispersion: -2.5 ps/km/nm @1550 nm) without dispersion compensation. The results indicate that a regional metro WDM network could be implemented cost-effectively by using the proposed negative dispersion fiber and direct modulated lasers.

Chemical signals coordinate the dispersal of a plant-parasitic nematode with the metamorphosis of its vector beetle

With the support by the National Natural Science Foundation of China and the Chinese Academy of Sciences,Prof.Sun Jianghua(孙江华),Zou Zhen and Zhao Lilin et al.at the State Key Laboratory of Integrated Management of Pest Insects and Rodents,Institute of Zoology,Chinese Academy of Sciences,uncovered that ascarosides coordinate the dispersal of a plant-parasitic nematode with the metamorphosis

A Simple Configuration for 40 Gbit/s CSRZ Signal Generation with Electrical Band-Limiting to Achieve Large Dispersion Tolerance

We present a novel configuration for carrier suppressed return-to-zero (CSRZ) signal generation, which only requires a single stage Mach-Zehnder (MZ) modulator in conjunction with an electrical mixer. Electrical band-limiting is also introduced to increase dispersion tolerance without causing additional penalty due to nonlinear effects in long haul dense wavelength division multiplexed (DWDM) CSRZ systems using conventional launch power levels.