Miniaturized laser is the key element for integrated on-chip photonic device. Semiconductor materials are excellent candidates for gain medium of microscale laser, especially for nanowire (NW) based lasers. However, optical diffraction law constrains the footprint of photonic NW based device with the scale of half wavelength. [1] While in hybrid metal-semiconductor plasmonic nanostructures, photon energy could be coupled into collective electron oscillations in the form of surface plasmon polaritons (SPPs) at a metal-dielectric interface, [2][3][4] which therefore provide an effective solution to overcome optical diffraction limit. Similar to photonic laser, plasmonic lasers get amplification of SPPs by energy transfer from nonradiative part excitons of semiconductor material, where semiconductor severs as the gain media driving the inversion of SPP population at the metal-dielectric interface. [5][6][7] The SPP lasers show superior capabilities in strong light-matter interaction, which have potential applications in integrated photonics, biosensors, and quantum information technologies. [8][9][10] A series of inorganic II-VI and III-V compound semiconductor plasmonic NW lasers have been achieved in GaN, ZnO, and CdS NWs [11][12][13][14][15] at room temperature, because these NWs gain medium produce sufficient gain to overcome the high losses in metals. The fabrication procedures usually require extreme conditions such as high-temperature or low-pressure conditions, leading to high cost. However, till now the thresholds of the resulting lasers are still high, low-cost gain materials with excellent gain characteristics are in urgent need to be exploited to overcome these problems.Recently, organic-inorganic lead halide perovskites (CH 3 NH 3 PbX 3 , X = Cl, Br, I) have attracted intensive attentions for their huge potential in photovoltaics, with a power conversion efficiency exceeded 22.1% in solar cells. [16] On the other hand, lead halide perovskites have emerged as promising optical gain materials for achieving low-threshold plasmonic lasers owing to their excellent optical properties in a wide spectrum range, such as large absorption coefficients, high photoluminescence (PL) quantum yield, and low nonradiative recombination rates. [17][18][19][20][21] In past few years, SPP lasers have been investigated in hybrid perovskites. For instance, Kao et al. demonstrated enhanced localized surface plasmonic lasing performance in solution-processed CH 3 NH 3 PbI 3 perovskite films in Plasmonic nanolaser holds great potential in breaking down the diffraction limit of conventional optics to the deep sub-wavelength regime and in ultrafast lasing dynamics. However, plasmonic laser devices are constrained in practical applications due to their high cost and high thresholds. All-inorganic cesium lead halide perovskites are promising solutions for their excellent optical gain properties and high emission efficiency. In this work, high-quality single-crystalline CsPbBr 3 perovskite nanowires (NWs) are synthesized by chemical ...

BackgroundIncreasing genetic and phenotypic differences found among natural isolates of C. elegans have encouraged researchers to explore the natural variation of this nematode species.ResultsHere we report on the identification of genomic differences between the reference strain N2 and the Hawaiian strain CB4856, one of the most genetically distant strains from N2. To identify both small- and large-scale genomic variations (GVs), we have sequenced the CB4856 genome using both Roche 454 (~400 bps single reads) and Illumina GA DNA sequencing methods (101 bps paired-end reads). Compared to previously described variants (available in WormBase), our effort uncovered twice as many single nucleotide variants (SNVs) and increased the number of small InDels almost 20-fold. Moreover, we identified and validated large insertions, most of which range from 150 bps to 1.2 kb in length in the CB4856 strain. Identified GVs had a widespread impact on protein-coding sequences, including 585 single-copy genes that have associated severe phenotypes of reduced viability in RNAi and genetics studies. Sixty of these genes are homologs of human genes associated with diseases. Furthermore, our work confirms previously identified GVs associated with differences in behavioural and biological traits between the N2 and CB4856 strains.ConclusionsThe identified GVs provide a rich resource for future studies that aim to explain the genetic basis for other trait differences between the N2 and CB4856 strains.

A wideband slot antenna with harmonic suppression is proposed to utilize the environment microwave energy. The antenna element is a printed narrow slot with an offset microstrip‐feed line to widen the operating band by generating the double resonance of similar frequencies. By adding a rectangular notch in the middle of slot element and grounding the microstrip terminal, its second‐order and third‐order harmonics are effectively suppressed. The experimental results of the prototype antenna show that the fractional bandwidth of its fundamental mode can reach 37.4%, while the antenna efficiencies of the second and third harmonics both are less than 23%. In the operating band the prototype antenna has the approximately omnidirectional radiation characteristic. This antenna structure also provides relaxed fabrication tolerances.

The water-insolubility of a potentially versatile photoresponsive 'turn-on' fluorescence probe was overcome by incorporating it into a nano-assembly containing an upconverting nanoparticle wrapped in an amphiphilic polymer. The appeal of the nano-system is not only in the ability to turn "on" and "off" the fluorescence from the organic chromophore using UV and visible light, it is in the fact that the nanoparticle acts as a static probe because it emits red and green light when excited by near infrared light, which is not effected by UV and visible light. This dual-functioning emission behaviour was demonstrated in live organisms.