Thermal near-field scattering characteristics for dielectric materials.

In this study, we passively analyzed the near-field characteristics of thermally excited evanescent waves, which are radiation waves generated by the local dynamics of materials, including electron motions and lattice vibrations. The thermally excited evanescent waves on aluminium nitride (AlN) and gallium nitride (GaN) were measured using passive spectroscopic scattering-type scanning near-field optical microscopy (s-SNOM) in the wavelength ranges of 10.5-12.

Development of a cryogenic passive-scattering-type near-field optical microscopy system.

Passive scattering-type, scanning near-field optical microscopy (s-SNOM) has been employed to study localized, long-wavelength infrared (LWIR) surface waves without external illumination. Here, we develop a cryogenic passive s-SNOM instrument in a vacuum chamber with 4 K liquid-helium cooling. Notably, the extremely low-temperature environment inside the chamber enables the realization of passive near-field detection with low background thermal noise.

Erlotinib with or without bevacizumab as a first-line therapy for patients with advanced nonsquamous epidermal growth factor receptor-positive non-small cell lung cancer: Exploratory subgroup analyses from the phase II JO25567 study.

Background: In the phase II JO25567 study (JapicCTI-111390), erlotinib plus bevacizumab demonstrated a significant clinical benefit in Japanese patients with epidermal growth factor receptor mutation-positive (EGFR+) non-small cell lung cancer (NSCLC). Here, we present an exploratory analysis investigating the impact of baseline pleural/pericardial effusion (PPE) on patient outcomes.

Methods: Patients with stage IIIB/IV or postoperative recurrent EGFR+ NSCLC were randomized 1:1 to receive erlotinib (150 mg/day) plus bevacizumab (15 mg/kg every 3 weeks) or erlotinib monotherapy.

Near-Field Radiative Nanothermal Imaging of Nonuniform Joule Heating in Narrow Metal Wires.

Probing spatial variation of temperature at the nanoscale provides key information for exploring diverse areas of modern science and technology. Despite significant progress in the development of contact thermometers with high spatial resolution, one inherent disadvantage is that the quantitative analysis of temperature can be complicated by the direct thermal contact. On the other hand, noncontact infrared radiation thermometer is free from such contact-induced disturbance, but suffers from insufficient spatial resolution stemming from diffraction-limit in the micrometer range.

Imaging of nonlocal hot-electron energy dissipation via shot noise.

In modern microelectronic devices, hot electrons accelerate, scatter, and dissipate energy in nanoscale dimensions. Despite recent progress in nanothermometry, direct real-space mapping of hot-electron energy dissipation is challenging because existing techniques are restricted to probing the lattice rather than the electrons. We realize electronic nanothermometry by measuring local current fluctuations, or shot noise, associated with ultrafast hot-electron kinetic processes (~21 terahertz).

A high signal-to-noise ratio passive near-field microscope equipped with a helium-free cryostat.

We have developed a passive long-wavelength infrared (LWIR) scattering-type scanning near-field optical microscope (s-SNOM) installed in a helium-free mechanically cooled cryostat, which facilitates cooling of an LWIR detector and optical elements to 4.5 K. To reduce mechanical vibration propagation from a compressor unit, we have introduced a metal bellows damper and a helium gas damper.

Tip size dependence of passive near-field microscopy.

We improve the spatial resolution and investigate the tip-sample coupling in a passive scattering-type scanning near-field optical microscope (s-SNOM), which probes thermally excited surface waves without any external light source. We study the spatial resolution, the intensity, and the decay behavior of the thermally excited near-field signals with different radii of curvatures of tungsten-tip apexes. We also study the tip size dependence of the interference pattern in the far-field region.

Nano-FTIR chemical mapping of minerals in biological materials.

Methods for imaging of nanocomposites based on X-ray, electron, tunneling or force microscopy provide information about the shapes of nanoparticles; however, all of these methods fail on chemical recognition. Neither do they allow local identification of mineral type. We demonstrate that infrared near-field microscopy solves these requirements at 20 nm spatial resolution, highlighting, in its first application to natural nanostructures, the mineral particles in shell and bone.

Thermally excited near-field radiation and far-field interference.

Thermal radiation from samples of Au layers patterned on GaAs, SiO(2), and SiC at 300 K are studied with a scattering-type scanning near-field optical microscope (wavelength: ~14.5 μm), without applying external illumination. Clear near-field images are obtained with a spatial resolution of ~60 nm.

Hydrogen sulfide production by sulfate-reducing bacteria utilizing additives eluted from plastic resins.

In the present study it was demonstrated that organic additives eluted from plastic resins could be utilized as substrates by sulfate-reducing bacteria. Two laboratory-scale experiments, a microcosm experiment and a leaching experiment, were conducted using polyvinyl chloride (PVC) as a model plastic resin. In the former experiment, the conversion of sulfate to sulfide was evident in microcosms that received plasticized PVC as the sole carbon source, but not in those that received PVC homopolymer.

A sensitive near-field microscope for thermal radiation.

A scattering-type scanning near-field optical microscope in long-wavelength infrared (LWIR) region is developed by using an extremely sensitive detector, called the charge-sensitive infrared phototransistor. A tungsten probe attached to a quartz tuning fork is controlled in shear-force mode. Evanescent wave at a sample surface is periodically scattered by slowly (2 Hz) modulating the probe in the direction normal to the sample surface.

A passive long-wavelength infrared microscope with a highly sensitive phototransistor.

A passive scanning confocal microscope in the long-wavelength infrared (LWIR) region has been developed for sensitive imaging of spontaneous LWIR radiation by utilizing an ultrahighly sensitive detector, called the charge-sensitive infrared phototransistor (CSIP). The microscope consisted of room-temperature components including a Ge objective lens and liquid helium temperature components including a confocal pinhole, Ge relay lenses, and CSIP detector. With the microscope, thermal radiation (wavelength of 14.