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To demonstrate a new MR imaging approach that unambiguously identifies and quantitates contrast agents based on intrinsic agent properties such as rTargeted and bioresponsive contrast agents were imaged in agarose phantoms to generate TMBI allowed the quantitative interpretation of intensities, removed confounding backgrounds, enabled contrast agent multiplexing, and unambiguously detected the activation and binding states of bioresponsive and targeted contrast agents.MBI has the potential to overcome significant limitations in the interpretation, quantitation, and multiplexing of contrast enhancement by MR imaging probes. Magn Reson Med 77:970-978, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

"H"-like organic nanowire heterojunctions with two parallel 2-acetyl-6-dimethylamino-naphthalene wires vertically bridged by one 2,4,5-triphenylimidazole wire are prepared via cooperative molecular assembly in liquid phase. The exciton conversion at the junction interfaces is beneficial for the design of multichannel light-controlled photo-switches. The results provide better understanding of molecular assembly toward specific structures and open up new prospects for the creation of novel photonic materials.

Advanced anode materials for high power and high energy lithium-ion batteries have attracted great interest due to the increasing demand for energy conversion and storage devices. Metal oxides (e.g., Fe3O4) usually possess high theoretical capacities, but poor electrochemical performances owing to their severe volume change and poor electronic conductivity during cycles. In this work, we develop a self-assembly approach for the synthesis of sandwich-structured graphene-Fe3O4@carbon composite, in which Fe3O4 nanoparticles with carbon layers are immobilized between the layers of graphene nanosheets. Compared to Fe3O4@carbon and bulk Fe3O4, graphene-Fe3O4@carbon composite shows superior electrochemical performance, including higher reversible capacity, better cycle and rate performances, which may be attributed to the sandwich structure of the composite, the nanosized Fe3O4, and the carbon layers on the surface of Fe3O4. Moreover, compared to the reported graphene-Fe3O4 composite, the particle size of Fe3O4 is controllable and the content of Fe3O4 in this composite can be arbitrarily adjusted for optimal performance. This novel synthesis strategy may be employed in other sandwich-structured nanocomposites design for high-performance lithium-ion batteries and other electrochemical devices.

Biocompatible Fe3O4 magnetic nanocrystals with reactive moieties on the surface can be prepared via a "one-pot" reaction and used straightforwardly in cancer detection by being coupled with a specific cancer-targeting antibody. It is demonstrated that the as-prepared Fe3O4 nanocrystals can potentially be used as effective magnetic resonance imaging (MRI) contrast agents for cancer diagnosis (see figure).

UNLABELLED • PREMISE OF THE STUDY There is an ongoing debate about the importance of whole-plant control vs. local modular mechanisms for root growth. We conducted a split-root experiment with different patch/background levels of nitrogen to examine whether local root growth and death are controlled by local resource levels or at the whole-plant level.• METHODS Three microrhizotrons with 0, 10, and 100 µg N/g growth medium levels (74 g growth medium each) were attached to pots of high or low soil N in which one Ailanthus altissima individual was growing. One fine root was guided into each of the microrhizotrons and photographed every 4 d. Plants were harvested after 28 d; root growth and mortality in the microrhizotrons were recorded. Changes in root length, number of laterals, and interlateral length were determined from the photos and analyzed.• KEY RESULTS While overall plant growth was influenced by background N level, both patch and background N levels influenced root growth and mortality in patches. Local roots proliferated most when the patch N level was high and background level low, and they proliferated least and showed highest mortality when patch N was low and the background level high.• CONCLUSIONS The fate of roots growing in a patch is influenced by the resource environment of the plant's other roots as well as the resource levels in the patch itself. Thus, the growth and death of roots in patches is determined by both modular and whole-plant mechanisms.

A one-pot reaction process was developed to synthesize highly dispersible, superparamagnetic Fe(3)O(4) nanoflowers; the potential of these nanoflowers as MRI contrast agents was investigated.

Magnetic resonance imaging (MRI) yields high spatially resolved contrast with anatomical details for diagnosis, deeper penetration depth and rapid 3D scanning. To improve imaging sensitivity, adding contrast agents accelerates the relaxation rate of water molecules, thereby greatly increasing the contrast between specific issues or organs of interest. Currently, the majority of T(1) contrast agents are paramagnetic molecular complexes, typically Gd(iii) chelates. Various nanoparticulate T(1) and T(1)/T(2) contrast agents have recently been investigated as novel agents possessing the advantages of both the T(1) contrast effect and nanostructural characteristics. In this minireview, we describe the recent progress of these inorganic nanoparticle-based MRI contrast agents. Specifically, we mainly report on Gd and Mn-based inorganic nanoparticles and ultrasmall iron oxide/ferrite nanoparticles.

The development of new types of high-performance nanoparticulate MR contrast agents with either positive (T(1)) or dual-contrast (both positive and negative, T(1) + T(2)) ability is of great importance. Here we report a facile synthesis of ultrasmall PEGylated iron oxide nanoparticles for dual-contrast T(1)- and T(2)-weighted MRI. The produced superparamagnetic iron oxide nanoparticles (SPIONs) are of high crystallinity and size uniformity with an average diameter of 5.4 nm, and can be individually dispersed in the physiological buffer with high stability. The SPIONs reveal an impressive saturation magnetization of 94 emu g(-1) Fe(3)O(4), the highest r(1) of 19.7 mM(-1) s(-1) and the lowest r(2)/r(1) ratio of 2.0 at 1.5 T reported so far for PEGylated iron oxide nanoparticles. T(1)- and T(2)-weighted MR images showed that the SPIONs could not only improve surrounding water proton signals in the T(1)-weighted image, but induce significant signal reduction in the T(2)-weighted image. The good contrast effect of the SPIONs as T(1) + T(2) dual-contrast agents might be due to its high magnetization, optimal nanoparticle size for T(1) + T(2) dual-contrast agents, high size monodispersity and excellent colloidal stability. In vitro cell experiments showed that the SPIONs have little effect on HeLa cell viability.

Magnetic resonance imaging (MRI) has become a powerful technique in biological molecular imaging and clinical diagnosis. With the rapid progress in nanoscale science and technology, nanostructure-based MR contrast agents are undergoing rapid development. This is in part due to the tuneable magnetic and cellular uptake properties, large surface area for conjugation and favourable biodistribution. In this review, we describe our recent progress in the development of high-performance nanostructured MR contrast agents. Specifically, we report on Gd-enriched nanostructured probes that exhibit T(1) MR contrast and superparamagnetic Fe(3)O(4) and CoFe(2)O(4) nanostructures that display T(2) MR contrast enhancement. The effects of nanostructure size, shape, assembly and surface modification on relaxivity are described. The potential of these contrast agents for in vitro and in vivo MR imaging with respect to colloidal stability under physiological conditions, biocompatibility, and surface functionality are also evaluated.