Corking Carbon Nanotube Cups with Gold Nanoparticles

Nitrogen doping of carbon nanotubes during chemical vapor deposition synthesis can create unique stacked cup-shaped structures termed as nitrogen-doped carbon nanotube cups (NCNCs). These cups have semielliptical hollow cavities and elevated reactivity which could lead to various applications. In this work, by applying intense ultrasonication to the as-synthesized NCNCs, we demonstrated an effective mechanical method to isolate the individual cups with opened cavities from their stacks. The graphitic structures of the isolated cups and their inherent nitrogen functionalities were characterized by comprehensive microscopic and spectroscopic methods. In particular, we quantitatively determined the existence of amine functionalities on NCNCs and found that they were preferentially distributed at the open edges of the cups, providing localized reactive sites. Further, by thiolating the amine groups with 3-mercapto-propionic acid, we were able to effectively cork the isolated cups by gold nanoparticles with commensurate diameters. These cup-shaped carbon nanomaterials with controlled inner volumes and gold nanoparticle corks could find potential applications as nanoscale reaction containers or drug delivery vehicles

Stoichiometric characteristics of soil C, N and P as affected by soil depth and plantation age.

<p>Values are the means ± SE of three plots. Values designated by different lowercase letters were significantly different among different duration ages, and different capital letters indicated significant difference soil layers, respectively (P < 0.05).</p

Soil, Leaf and Root Ecological Stoichiometry of <i>Caragana korshinskii</i> on the Loess Plateau of China in Relation to Plantation Age

<div><p><i>Caragana korshinskii</i>, a leguminous shrub, a common specie, is widely planted to prevent soil erosion on the Loess Plateau. The objective of this study was to determine how the plantation ages affected soil, leaf and root nutrients and ecological stoichiometry. The chronosequence ages of <i>C</i>. <i>korshinskii</i> plantations selected for this study were 10, 20 and 30 years. Soil organic carbon (SOC) and soil total nitrogen (STN) of <i>C</i>. <i>korshinskii</i> plantations significantly increased with increase in the chronosequence age. However, soil total phosphorous (STP) was not affected by the chronosequence age. The soil C: N ratio decreased and the soil C: P and N: P ratios increased with increasing plantation age. The leaf and root concentrations of C, N, and P increased and the ratios C: N, C: P, and N: P decreased with age increase. Leaf N: P ratios were >20, indicating that P was the main factor limiting the growth of <i>C</i>. <i>korshinskii</i>. This study also demonstrated that the regeneration of natural grassland (NG) effectively preserved and enhanced soil nutrient contents. Compared with NG, shrub lands (<i>C</i>. <i>korshinskii</i>) had much lower soil nutrient concentrations, especially for long (>20 years) chronosequence age. Thus, the regeneration of natural grassland is an ecologically beneficial practice for the recovery of degraded soils in this area.</p></div

Stoichiometric characteristics of plant and soil C:N:P as affected by plantation age and soil depth.

<p>Stoichiometric characteristics of plant and soil C:N:P as affected by plantation age and soil depth.</p

Stoichiometric characteristics of leaf and root C, N and P as affected by plantation age.

<p>Values are the means ± SE of three plots. For each plant issue, means with different letters are significantly different based on ANOVA and Scheffe’s test (<i>P</i><0.05). Note: Values designated by different lowercase letters were significantly different among different duration ages, and different capital letters indicated significant difference between leaf and root, respectively (<i>P</i> < 0.05).</p

Relationships between soil, leaf and root stoichiometric characteristics of <i>C.korshinskii</i>.

<p>Relationships between soil, leaf and root stoichiometric characteristics of <i>C.korshinskii</i>.</p

Electronic Detection of Bacteria Using Holey Reduced Graphene Oxide

Carbon nanomaterials have been widely explored for diverse biosensing applications including bacterial detection. However, covalent functionalization of these materials can lead to the destruction of attractive electronic properties. To this end, we utilized a new graphene derivative, holey reduced graphene oxide (hRGO), functionalized with Magainin I to produce a broad-spectrum bacterial probe. Unlike related carbon nanomaterials, hRGO retains the necessary electronic properties while providing the high percentage of available oxygen moieties required for effective covalent functionalization

Electronic Detection of Lectins Using Carbohydrate-Functionalized Nanostructures: Graphene <i>versus</i> Carbon Nanotubes

Here we investigated the interactions between lectins and carbohydrates using field-effect transistor (FET) devices comprised of chemically converted graphene (CCG) and single-walled carbon nanotubes (SWNTs). Pyrene- and porphyrin-based glycoconjugates were functionalized noncovalently on the surface of CCG-FET and SWNT-FET devices, which were then treated with 2 μM nonspecific and specific lectins. In particular, three different lectins (PA-IL, PA-IIL, and ConA) and three carbohydrate epitopes (galactose, fucose, and mannose) were tested. The responses of 36 different devices were compared and rationalized using computer-aided models of carbon nanostructure/glycoconjugate interactions. Glycoconjugate surface coverage in addition to one-dimensional structures of SWNTs resulted in optimal lectin detection. Additionally, lectin titration data of SWNT- and CCG-based biosensors were used to calculate lectin dissociation constants (<i>K</i>_d) and compare them to the values obtained from the isothermal titration microcalorimetry technique

Nischarin is highly expressed in the brain of adult rats.

<p>(<b>A</b>) Total mRNA extracted from heart, lung, liver, kidney, stomach, small intestine, brain and spinal cord of adult rats was assayed by quantitative real-time PCR (n = 5). Relative quantification was assessed by normalizing the amount of Nischarin to the housekeeping gene GAPDH. (<b>B, C</b>) Protein samples from different tissues were analyzed by Western blot and the quantitative analysis was performed by normalizing the intensities of the hybridization signals to GAPDH (n = 5). Nischarin is highly expressed in liver, brain and spinal cord at both the mRNA and protein levels. Data are presented as mean ± SD.</p

Three-Dimensional Printable High-Temperature and High-Rate Heaters

High temperature heaters are ubiquitously used in materials synthesis and device processing. In this work, we developed three-dimensional (3D) printed reduced graphene oxide (RGO)-based heaters to function as high-performance thermal supply with high temperature and ultrafast heating rate. Compared with other heating sources, such as furnace, laser, and infrared radiation, the 3D printed heaters demonstrated in this work have the following distinct advantages: (1) the RGO based heater can operate at high temperature up to 3000 K because of using the high temperature-sustainable carbon material; (2) the heater temperature can be ramped up and down with extremely fast rates, up to ∼20 000 K/second; (3) heaters with different shapes can be directly printed with small sizes and onto different substrates to enable heating anywhere. The 3D printable RGO heaters can be applied to a wide range of nanomanufacturing when precise temperature control in time, placement, and the ramping rate are important