Most known plant viruses are spread from plant to plant by insect vectors. There is strong evidence that nonpersistently transmitted viruses manipulate the release of plant volatiles to attract insect vectors, thereby promoting virus spread. The mechanisms whereby aphid settling and feeding is altered on plants infected with these viruses, however, are unclear. Here we employed loss-of-function mutations in cucumber mosaic virus (CMV) and one of its host plants, tobacco (Nicotiana tabacum), to elucidate such mechanisms. We show that, relative to a CMVD2b strain with a deletion of the viral suppressor of RNAi 2b protein in CMV, plants infected with wild-type CMV produce higher concentrations of the reactive oxygen species (ROS) H 2 O 2 in plant tissues. Aphids on wild-type CMV-infected plants engage in shorter probes, less phloem feeding, and exhibit other changes, as detected by electrical penetration graphing technology, relative to CMVD2b-infected plants. Therefore, the frequency of virus acquisition and the virus load per aphid were greater on CMV-infected plants than on CMVD2b-infected plants. Aphids also moved away from initial feeding sites more frequently on wild-type CMV infected versus CMVD2b-infected plants. The role of H 2 O 2 in eliciting these effects on aphids was corroborated using healthy plants infused with H 2 O 2. Finally, H 2 O 2 levels were not elevated, and aphid behavior was unchanged, on CMV-infected RbohD-silenced tobacco plants, which are deficient in the induction of ROS production. These results suggest that CMV uses its viral suppressor of RNAi protein to increase plant ROS levels, thereby enhancing its acquisition and transmission by vector insects.

In the last couple of decades, there has been a lot of progress in the synthesis methods of nano-structural materials, but still the field has a large number of puzzles to solve. Metal nanowires (NWs) and their alloys represent a sub category of the 1-D nano-materials and there is a large effort to study the microstructural, physical and chemical properties to use them for further industrial applications. Due to technical limitations of single component NWs, the hetero-structured materials gained attention recently. Among them, multi-segmented NWs are more diverse in applications, consisting of two or more segments that can perform multiple function at a time, which confer their unique properties. Recent advancement in characterization techniques has opened up new opportunities for understanding the physical properties of multi-segmented structures of 1-D nanomaterials. Since the multi-segmented NWs needs a reliable response from an external filed, numerous studies have been done on the synthesis of multi-segmented NWs to precisely control the physical properties of multi-segmented NWs. This paper highlights the electrochemical synthesis and physical properties of multi-segmented NWs, with a focus on the mechanical and magnetic properties by explaining the shape, microstructure, and composition of NWs.

We demonstrate a versatile nanoparticle with imaging-guided chemo−photothermal synergistic therapy and EpCAM-targeted delivery of liver tumor cells. EpCAM antibody (anti-EpCAM) and Pt(IV) were grafted onto the polydopamine carbon dots (PDA-CDs) by the amidation reaction. The EpCAM antibody of particles enables the targeted interaction with liver progenitor cells due to their overexpressed EpCAM protein. The tetravalent platinum prodrug [Pt(IV)] induces apoptosis with minimum toxic side effects through the interaction between cisplatin and tumor cell DNA. The nanoparticles displayed stable photothermal property and considerable anti-tumor therapeutic effect in vivo. Coupling with cellular imaging due to their fluorescence property,

Magnetic nanostructures and nanomaterials play essential roles in modern bio medicine and technology. Proper surface functionalization of nanoparticles (NPs) allows the selective bonding thus application of magnetic forces to a vast range of cellular structures and biomolecules. However, the spherical geometry of NPs poises a series of limitations in various potential applications. Mostly, typical spherical core shell structure consists of magnetic and non-magnetic layers have little tunability in terms of magnetic responses, and their single surface functionality also limits chemical activity and selectivity. In comparison to spherical NPs, nanowires (NWs) possess more degrees of freedom in achieving magnetic and surface chemical tenability. In addition to adjustment of magnetic anisotropy and inter-layer interactions, another important feature of NWs is their ability to combine different components along their length, which can result in diverse bio-magnetic applications. Magnetic NWs have become the candidate material for biomedical applications owing to their high magnetization, cheapness and cost effective synthesis. With large magnetic moment, anisotropy, biocompatibility and low toxicity, magnetic NWs have been recently used in living cell manipulation, magnetic cell separation and magnetic hyperthermia. In this review, the basic concepts of magnetic characteristics of nanoscale objects and the influences of aspect ratio, composition and diameter on magnetic properties of NWs are addressed. Some underpinning physical principles of magnetic hyperthermia (MH), magnetic resonance imaging (MRI) and magnetic separation (MS) have been discussed. Finally, recent studies on magnetic NWs for the applications in MH, MRI and MS were discussed in detail.

To overcome the negative contrast limitations, and to improve the sensitivity of the magnetic resonance signals, the mesoporous silica coated Fe/Mn multilayered nanowires (NWs) were used as a T1–T2 dual‐mode contrast agents (CAs). The single component Fe and Mn NWs, and Fe/Mn multilayer NWs were synthesized by electrodeposition in the homemade anodic aluminum oxide (AAO) templates with the aperture of about 30 nm. The structural characterization and morphology of single component and multisegmented NWs was done by X‐ray diffraction and transmission electron microscopy. The elemental composition of Fe/Mn multilayerd NWs was confirmed by energy‐dispersive X‐ray and energy‐dispersive spectrometer. Vibrating sample magnetometer was used to test the magnetic properties, and 1.5 T magnetic resonance imaging (MRI) scanner was used to measure the relaxation efficiency. Importantly, the MRI study indicated that the Fe/Mn multilayer NWs showed a significant T1–T2 imaging effect, and have longitudinal relaxivity (r1) value, that is, 1.25 ± 0.0329 × 10−4 μM−1 s−1 and transverse relaxivity (r2), that is, 5.13 ± 0.123 × 10−4 μM−1 s−1, which was two times of r1 value (0.654 ± 0.00899 × 10−4 μM−1 s−1) of Mn NWs, and r2 value (2.96 ± 0.0415 × 10−4 μM−1 s−1) of Fe NWs. Hence, Fe/Mn multilayer NWs have potential to be used as T1–T2 dual‐mode CAs.

Previous research has shown that elevated CO2 reduces plant resistance against insects and enhances the water use efficiency of C3 plants, which improves the feeding efficiency of aphids. Although plant mitogen-activated protein kinases (MAPKs) are known to regulate water relations and phytohormone-mediated resistance, little is known about the effect of elevated CO2 on MAPKs and the cascading effects on aphids. By using stably transformed Nicotiana attenuata plants silenced in MPK4, wound-induced protein kinase (WIPK), or salicylic acid-induced protein kinase (SIPK), we determined the functions of MAPKs in plant-aphid interactions and their responses to elevated CO2. The results showed that among all plant genotypes, inverted repeat MPK4 plants had the largest stomatal apertures, the lowest water content, the strongest jasmonic acid (JA)-dependent resistance, and the lowest aphid numbers, suggesting that MPK4 affects plant responses to aphids by regulating stomatal aperture and JA-dependent resistance. Regardless of aphid infestation, elevated CO2 up-regulated MPK4, but not WIPK or SIPK, in wild-type plants. Elevated CO2 increased the number, mean relative growth rate, and feeding efficiency of aphids on all plant genotypes except inverted repeat MPK4. We conclude that MPK4 is a CO2-responsive plant determinant that regulates the molecular interaction between plants and aphids.

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