We report on a promising approach for the label-free analysis of DNA molecules with electromagnetic surface waves in the terahertz (THz) region. A metallic mesh with a polyvinylidene difluoride membrane is employed for THz transmission analysis. The metallic mesh with opening holes provides a sharp dip structure in a THz transmission spectrum, which is sensitive to a small change of the refractive index of a sample on the metallic mesh surface. The optical properties of a small amount of DNA molecules cannot be investigated by a free-space THz measurement because of the low absorption coefficients of such samples. However, metallic mesh-based THz measurement revealed the difference in optical properties between single- and double-stranded DNA molecules on the basis of refractive index, as estimated from a dip frequency shift of the metallic mesh. Therefore, our metallic-based THz technique provides a dramatically enhanced sensitivity, and demonstrates the potential of our approach of the analysis of biologically relevant DNA samples.

We present in this work advanced results concerning heat shielding based on assembled sheets of In 2 O 3 :Sn nanoparticles (ITO-NP sheets) in terms of particle size and interparticle gap. We demonstrate that the oxide semiconductor nanoparticles are crucial to achieve required optical properties relevant to energy-saving applications. In the infrared (IR) range, strong electric-field (E-field) interactions between NPs are formed locally at narrow interparticle gaps. Changes in thickness and particle size greatly increase the magnitude and peak separation of the resonant reflectance, which widely covers the IR range. As a consequence, the size-dependent plasmonic properties contribute to high heat-shielding efficiency. As confirmed by electrodynamic simulations, plasmonic coupling results in these spectral changes due to three-dimensional E-field interactions along the in-plane and out-of-plane directions. Moreover, the resonant reflectance is tuned by mechanical stretchable strains, indicating one of the important factors for determining the resonant reflectance in addition to the control of particle size. From another perspective, the interparticle gap markedly affects the mechanism of electron transport in the NP sheets. The high electromagnetic transmission in the microwave range was due to the low electrical conductance caused by the spatial confinement of free carriers into the NPs. These results promoted development of flexible heat shielding in which optical and electromagnetic control is feasible for a wide range of wavelengths from ultraviolet to microwaves. Control of particle size and interparticle gap revealed important aspects that should be considered in structural design when fabricating heat-shielding materials.

This paper describes infrared plasmonic responses in three-dimensional (3D) assembled films of In2O3:Sn nanoparticles (NPs). The introduction of surface modifications to NPs can facilitate the production of electric-field interactions between NPs due to the creation of narrow crevices in the NP interfaces. In particular, the electric-field interactions along the in-plane and out-of-plane directions in the 3D assembled NP films allow for resonant splitting of plasmon excitations to the quadrupole and dipole modes, thereby realizing selective high reflections in the near- and mid-infrared range, respectively. The origins of these plasmonic properties were revealed from electric-field distributions calculated by electrodynamic simulations that agreed well with experimental results. The interparticle gaps and their derived plasmon couplings play an important role in producing high reflective performances in assembled NP films. These 3D assemblies of NPs can be further extended to produce large-size flexible films with high infrared reflectance, which simultaneously exhibit microwave transmittance essential for telecommunications. This study provides important insights for harnessing infrared optical responses using plasmonic technology for the fabrication of infrared thermal-shielding applications.

Near-infrared Er photoluminescence (PL) is markedly modified using a plasmonic In2O3: Sn nanoparticle (NP) sheet. Modeling and optical measurements reveal the presence of different electric fields (E-field) in the NP sheet. The local E-field excited at the interface between the NP sheet and Er-emitting layer of ZnO contributes significantly towards the spectral modifications of Er PL due to matching with the photon energy of Er PL. We also determine the critical temperature for Er PL modifications, which is related to the energy transfer efficiency between Er transition dipoles in ZnO and the plasmon modes on the NP sheet.

Hepatocellular carcinoma (HCC) shows many pathological features, and it varies architecturally and cytologically. There have been many reports and discussions of the morphological features of HCC. A 63-year-old man was found to have a solitary tumor in liver segment 7 that was diagnosed as HCC. A partial resection of liver segment 7 was performed. Microscopically, the tumor lesion showed a moderately differentiated HCC. There was also a lesion with foamy histiocyte-like cells corresponding to the white lesion in the face of the cut tumor. Immunohistochemical staining showed that they were negative for CD68, S-100, vimentin, and HMB-45. The cytoplasm itself was negative on periodic acid Schiff (PAS) and Sudan staining. Without immunohistological analysis, it is difficult to distinguish this HCC variant from clear cell carcinoma or metastases of renal cell carcinoma. It is important to recognize this type as a specific cytological variant of HCC that requires confirmation by immunohistochemistry. This report describes the case of a patient with a morphologically distinctive pattern of HCC with prominent cell cytoplasm that had a foamy histiocyte-like appearance. To the best of our knowledge, this is the first report of this HCC variant.