Evaluating the diversity of circulating natural killer cells between active tuberculosis and latent tuberculosis infection.

Tuberculosis (TB) is a leading global public health problem; however, the mechanisms underlying the immunopathology of TB progression are not well understood. It is currently believed that Mycobacterium tuberculosis (Mtb) infection can modify natural killer (NK) cell phenotypic signatures. Hence, our study was designed to investigate the diversity of circulating NK cells in patients with different TB infection status.

Linear Scaling of the Exciton Binding Energy versus the Band Gap of Two-Dimensional Materials.

The exciton is one of the most crucial physical entities in the performance of optoelectronic and photonic devices, and widely varying exciton binding energies have been reported in different classes of materials. Using first-principles calculations within the GW-Bethe-Salpeter equation approach, here we investigate the excitonic properties of two recently discovered layered materials: phosphorene and graphene fluoride. We first confirm large exciton binding energies of, respectively, 0.

Role of the dispersion force in modeling the interfacial properties of molecule-metal interfaces: adsorption of thiophene on copper surfaces.

We present density functional theory calculations of the geometry, adsorption energy and electronic structure of thiophene adsorbed on Cu(111), Cu(110) and Cu(100) surfaces. Our calculations employ dispersion corrections and self-consistent van der Waals density functionals (vdW-DFs). In terms of speed and accuracy, we find that the dispersion-energy-corrected Revised Perdue-Burke-Enzerhof (RPBE) functional is the "best balanced" method for predicting structural and energetic properties, while vdW-DF is also highly accurate if a proper exchange functional is used.

Suppression of grain boundaries in graphene growth on superstructured Mn-Cu(111) surface.

As undesirable defects, grain boundaries (GBs) are widespread in epitaxial graphene using existing growth methods on metal substrates. Employing density functional theory calculations, we first identify that the misorientations of carbon islands nucleated on a Cu(111) surface lead to the formation of GBs as the islands coalesce. We then propose a two-step kinetic pathway to effectively suppress the formation of GBs.

Quantum efficiency of intermediate-band solar cells based on non-compensated n-p codoped TiO2.

As an appealing concept for developing next-generation solar cells, intermediate-band solar cells (IBSCs) promise to drastically increase the quantum efficiency of photovoltaic conversion. Yet to date, a standing challenge lies in the lack of materials suitable for developing IBSCs. Recently, a new doping approach, termed non-compensated n-p codoping, has been proposed to construct intermediate bands (IBs) in the intrinsic energy band gaps of oxide semiconductors such as TiO(2).

Deriving carbon atomic chains from graphene.

Stable and rigid carbon atomic chains were experimentally realized by removing carbon atoms row by row from graphene through the controlled energetic electron irradiation inside a transmission electron microscope. The observed structural dynamics of carbon atomic chains such as formation, migration, and breakage were well explained by density-functional theory calculations. The method we reported here is promising to investigate all-carbon-based devices with the carbon atomic chains as the conducting channel, which can be regarded as the ultimate basic component of molecular devices.

Metal atom catalyzed enlargement of fullerenes.

A metal catalyzed enlargement of fullerenes has been demonstrated by in situ high-resolution transmission electron microscopy. It was found that carbon atoms and clusters can be continuously incorporated into a closed fullerene cage at a high temperature, leading to an increase in the diameter and consequently the formation of giant fullerene with the assist of adsorbed metal atoms. Density functional theoretical simulations indeed suggest that the activation energy for the carbon incorporation and the associated Stone-Wales transformation can be substantially reduced due to the presence of metal atoms, which should be of key importance for the fullerene growth.