Plasmonic photocatalysis has recently facilitated the rapid progress in enhancing photocatalytic efficiency under visible light irradiation, increasing the prospect of using sunlight for environmental and energy applications such as wastewater treatment, water splitting and carbon dioxide reduction. Plasmonic photocatalysis makes use of noble metal nanoparticles dispersed into semiconductor photocatalysts and possesses two prominent features-a Schottky junction and localized surface plasmonic resonance (LSPR). The former is of benefit to charge separation and transfer whereas the latter contributes to the strong absorption of visible light and the excitation of active charge carriers. This article aims to provide a systematic study of the fundamental physical mechanisms of plasmonic photocatalysis and to rationalize many experimental observations. In particular, we show that LSPR could boost the generation of electrons and holes in semiconductor photocatalysts through two different effects-the LSPR sensitization effect and the LSPR-powered bandgap breaking effect. By classifying the plasmonic photocatalytic systems in terms of their contact form and irradiation state, we show that the enhancement effects on different properties of photocatalysis can be well-explained and systematized. Moreover, we identify popular material systems of plasmonic photocatalysis that have shown excellent performance and elucidate their key features in the context of our proposed mechanisms and classifications.

Recent advances in transition metal nitride-based catalysts for efficient electrochemical water splitting have been reviewed.

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Metamaterials have attracted intensive research interest in recent years because their optical properties have a strong dependence on the geometry of metamaterial molecules rather than the material composition. [1][2][3] This feature has inspired the creation and tailoring of exotic properties, such as a negative refractive index, [ 4 , 5 ] perfect absorption, [ 6 ] and super lensing, [ 7 , 8 ] which are not readily available in nature. For many practical applications such as data storage [ 9 ] and optical switching, [ 10 ] switchable metamaterials that possess very different states are almost a necessity. [ 11 ] Most of the tunable metamaterials that have been demonstrated rely on tuning constituent materials or changing surrounding media by introducing natural materials with higher tunability, such as liquid crystals and phase changing materials. [12][13][14][15][16][17][18][19] However, this limits the choices of materials and becomes increasingly diffi cult to implement at higher frequencies. Moreover, the tuning range is usually too limited to achieve a switching effect between strikingly different states.A complementary approach is to mechanically reconfi gure the metamaterial molecules. [ 20 , 21 ] Micromachining technology has been developed for fabrication and actuation of micromechanical devices [22][23][24][25][26] with switching frequencies up to the GHz level. [ 27 ] An attempt was made to adjust the distance between several planar metamaterial layers in which effi cient transmission change was achieved but the tuning originated from a change in the layer structure rather than a change in metamaterial molecule. [ 22 ] Recently, another interesting work demonstrated the modifi cation of the optical properties of a metamaterial by reorienting the metamaterial molecules. [ 23 ] Inspired by these prior studies, we report the concept and design of switchable magnetic metamaterials by directly reshaping the metamaterial molecules using the micromachining technology and present working devices with switchable magnetic responses.The schematic diagram of the switchable magnetic metamaterial is shown in Figure 1 a. Each metamaterial molecule consists of two semi-square split rings. One is anchored on the substrate while the other can be moved by micromachined actuators. As a result, the gap between the split rings can be altered and thus the geometric shape of the metamaterial molecule can be changed. Figure 1 b-d illustrates the two semi-square spit rings in different states. In Figure 1 b, the two split rings are separated by a small gap, resulting in a geometric shape "[]". This is a typical split ring resonator. [ 28 ] For simple notation, this state is called the open-ring state. Figure 1 c,d show two extreme cases. In the former, the gap between the two split rings is closed and the actual metamaterial molecule becomes a closed ring in the "ٗ" shape. This is called the closed-ring state. In the latter, the movable ring is moved away until it touches the back side of the fi xed ring in the next metama...

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A cellular protein, previously described as p35͞38, binds to the complementary (؊)-strand of the leader RNA and intergenic (IG) sequence of mouse hepatitis virus (MHV) RNA. The extent of the binding of this protein to IG sites correlates with the efficiency of the subgenomic mRNA transcription from that IG site, suggesting that it is a requisite transcription factor. We have purified this protein and determined by partial peptide sequencing that it is heterogeneous nuclear ribonucleoprotein (hnRNP) A1, an abundant, primarily nuclear protein. hnRNP A1 shuttles between the nucleus and cytoplasm and plays a role in the regulation of alternative RNA splicing. The MHV(؊)-strand leader and IG sequences conform to the consensus binding motifs of hnRNP A1. Recombinant hnRNP A1 bound to these two RNA regions in vitro in a sequence-specific manner. During MHV infection, hnRNP A1 relocalizes from the nucleus to the cytoplasm, where viral replication occurs. These data suggest that hnRNP A1 is a cellular factor that regulates the RNA-dependent RNA transcription of the virus.

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With the recent emergence of Middle East Respiratory Syndrome coronavirus in humans and the outbreak of devastating porcine epidemic diarrhea coronavirus in swine, therapeutic intervention is urgently needed. However, anti-coronavirus drugs currently are not available. In an effort to assist rapid development of anti-coronavirus drugs, here we screened the NIH Clinical Collection in cell culture using a luciferase reporter-expressing recombinant murine coronavirus. Of the 727 compounds screened, 84 were found to have a significant anti-coronavirus effect. Further experiments revealed that 51 compounds blocked virus entry while 19 others inhibited viral replication. Additional validation studies with the top 3 inhibitors (hexachlorophene, nitazoxanide and homoharringtonine) demonstrated robust anti-coronavirus activities (a reduction of 6 to 8log10 in virus titer) with an IC50 ranging from 11nM to 1.2μM. Furthermore, homoharringtonine and hexachlorophene exhibited broad antiviral activity against diverse species of human and animal coronaviruses. Since the NIH Clinical Collection consists of compounds that have already been through clinical trials, these small molecule inhibitors have a great potential for rapid development as anti-coronavirus drugs.