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Hydrogen sulfide (H 2 S) is a gaseous signaling agent that has important regulatory roles in many biological systems but remains difficult to measure in living biological specimens. Herein, we report a novel near-infrared (NIR) activated surface-enhanced Raman scattering (SERS) nanosensor for in vitro and in vivo H 2 S assay utilizing Au/Ag alloy nanoboxes with local surface plasmon resonance (LSPR) at 741 nm. This detection is realized by SERS spectrum changes of the NIR probes, which are labeled on Au/Ag nanoboxes under NIR laser irradiation, resulting from the reaction of H 2 S with Ag in the substrate of Au/Ag nanoboxes. Owing to the wellmatching between the incident laser light frequency and the LSPR of the substrates at the NIR region, this SERS nanosensor with a high selectivity and sensitivity can be utilized to monitor the distribution of H 2 S in living cells and zebrafish embryos. Noticeably, the NIR SERS signal is detectable in tissues at depths of up to 12 mm, demonstrating its huge potential in the in vivo studies of pathophysiological processes involving H 2 S.

The detection of the New Moon at sunset is of importance to communities based on the lunar calendar. This is traditionally undertaken with visual observations. We propose a radio method which allows a higher visibility of the Moon relative to the Sun and consequently gives us the ability to detect the Moon much closer to the Sun than is the case of visual observation. We first compare the relative brightness of the Moon and Sun over a range of possible frequencies and find the range 5-100 GHz to be suitable. The next consideration is the atmospheric absorption/emission due to water vapour and oxygen as a function of frequency. This is particularly important since the relevant observations are near the horizon. We show that a frequency of ∼ 10 GHz is optimal for this programme. We have designed and constructed a telescope with a FWHM resolution of 0 • .6 and low sidelobes to demonstrate the potential of this approach. At the time of the 21 May 2012 New Moon the Sun/Moon brightness temperature ratio was 72.7 ± 2.2 in agreement with predictions from the literature when combined with the observed sunspot numbers for the day. The Moon would have been readily detectable at ∼ 2 • from the Sun. Our observations at 16 hr 36 min UT indicated that the Moon would have been at closest approach to the Sun 16 hr 25 min earlier; this was the annular solar eclipse of 00 hr 00 min UT on 21 May 2012.

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