Hierarchical zero- and one-dimensional topological states in symmetry-controllable grain boundary.

Structural imperfections can be a promising testbed to engineer the symmetries and topological states of solid-state platforms. Here, we present direct evidence of hierarchical transitions of zero- (0D) and one-dimensional (1D) topological states in symmetry-enforced grain boundaries (GB) in 1T'-MoTe. Using a scanning tunneling microscope tip press-and-pulse procedure, we construct two distinct types of GBs, which are differentiated by the underlying symmorphic and nonsymmorphic symmetries.

Remembering the Work of Phillip L. Geissler: A Coda to His Scientific Trajectory.

Phillip L. Geissler made important contributions to the statistical mechanics of biological polymers, heterogeneous materials, and chemical dynamics in aqueous environments. He devised analytical and computational methods that revealed the underlying organization of complex systems at the frontiers of biology, chemistry, and materials science.

Breakdown of chiral recognition of amino acids in reduced dimensions.

The homochirality of amino acids in living organisms is one of the great mysteries in the phenomena of life. To understand the chiral recognition of amino acids, we have used scanning tunnelling microscopy to investigate the self-assembly of molecules of the amino acid tryptophan (Trp) on Au(111). Earlier experiments showed only homochiral configurations in the self-assembly of amino acids, despite using a mixture of the two opposite enantiomers.

Unraveling the Structural and Electronic Properties of Graphene/Ge(110).

The direct growth of graphene on a semiconducting substrate opens a new avenue for future graphene-based applications. Understanding the structural and electronic properties of the graphene on a semiconducting surface is key for realizing such structures; however, these properties are poorly understood thus far. Here, we provide insight into the structural and electronic properties of graphene grown directly on a Ge(110) substrate.

Considerations for physicians using ketamine for sedation of children in emergency departments.

Objective: Ketamine use in emergency departments (EDs) for procedural sedation and analgesia is becoming increasingly common. However, few studies have examined patient factors related to adverse events associated with ketamine. This study investigated factors for consideration when using ketamine to sedate pediatric ED patients.

Outpatient Palliative Care and Aggressiveness of End-of-Life Care in Patients with Metastatic Colorectal Cancer.

Background: Palliative care in outpatient setting has been shown to promote better symptom management and transition to hospice care among patients with advanced cancer. Nevertheless, specialized palliative care is rarely provided at cancer centers in Korea. Herein, we aimed to assess aggressiveness of end-of-life care for patients with metastatic colorectal cancer according to the use of outpatient palliative care (OPC) at a single cancer center in Korea.

Nanoscale control of phonon excitations in graphene.

Phonons, which are collective excitations in a lattice of atoms or molecules, play a major role in determining various physical properties of condensed matter, such as thermal and electrical conductivities. In particular, phonons in graphene interact strongly with electrons; however, unlike in usual metals, these interactions between phonons and massless Dirac fermions appear to mirror the rather complicated physics of those between light and relativistic electrons. Therefore, a fundamental understanding of the underlying physics through systematic studies of phonon interactions and excitations in graphene is crucial for realising graphene-based devices.

Surface energy-mediated construction of anisotropic semiconductor wires with selective crystallographic polarity.

ZnO is a wide band-gap semiconductor with piezoelectric properties suitable for opto-electronics, sensors, and as an electrode material. Controlling the shape and crystallography of any semiconducting nanomaterial is a key step towards extending their use in applications. Whilst anisotropic ZnO wires have been routinely fabricated, precise control over the specific surface facets and tailoring of polar and non-polar growth directions still requires significant refinement.

Heterogeneous stacking of nanodot monolayers by dry pick-and-place transfer and its applications in quantum dot light-emitting diodes.

Layered assembly structures composed of nanomaterials, such as nanocrystals, have attracted considerable attention as promising candidates for new functional devices whose optical, electromagnetic and electronic behaviours are determined by the spatial arrangement of component elements. However, difficulties in handling each constituent layer in a material-specific manner limit the 3D integration of disparate nanomaterials into the appropriate heterogeneous electronics. Here we report a pick-and-place transfer method that enables the transfer of large-area nanodot assemblies.

Porous PVDF as effective sonic wave driven nanogenerators.

Piezomaterials are known to display enhanced energy conversion efficiency at nanoscale due to geometrical effect and improved mechanical properties. Although piezoelectric nanowires have been the most widely and dominantly researched structure for this application, there only exist a limited number of piezomaterials that can be easily manufactured into nanowires, thus, developing effective and reliable means of preparing nanostructures from a wide variety of piezomaterials is essential for the advancement of self-powered nanotechnology. In this study, we present nanoporous arrays of polyvinylidene fluoride (PVDF), fabricated by a lithography-free, template-assisted preparation method, as an effective alternative to nanowires for robust piezoelectric nanogenerators.

Self-assembly of magnetic nanoparticles in evaporating solution.

When deposited from an evaporating solution onto a substrate, even nondescript nanoparticles can organize into intricate spatial patterns. Here we show that a simple but long-ranged anisotropy in nanoparticles' interactions can greatly enrich this scenario. In experiments with colloidal Co nanocrystals, which bear a substantial magnetic dipole, we observe assemblies quite distinct from those formed by nonmagnetic particles.