Spectral dependence of third-order susceptibility of Au triangular nanoplates.

We experimentally investigated the spectral dependence of the third-order susceptibility [Formula: see text] of Au triangular nanoplates in a broad wavelength region (400-1,000 nm). Complex shaped plasmonic nanoparticles provide a promising route to achieve control of their optical properties at the nanoscale. However, little is known about the effects of geometrical parameters to the optical nonlinearities and underlying mechanisms of the plasmon modes. Here, we obtained the [Formula: see text] of Au triangular nanoplates featuring a narrow plasmon resonance that is tunable in the visible and near-IR regions. This work demonstrates that the plasmonic triangular nanoplates simultaneously shows self-focusing and -defocusing, and saturable and reverse-saturable absorption properties at specific wavelength regions. Maximum amplitudes of real and imaginary components are - 6.8 × 10-18 m2/V2 at 668 nm and - 6.7 × 10-18 m2/V2 at 646 nm, respectively. Spectral dependence of the quantity [Formula: see text] enables comparison between different shaped plasmonic NPs to boost active plasmonic applications performance.

Microscopic characterization of Fe nanoparticles formed on SrTiO3(001) and SrTiO3(110) surfaces.

Fe nanoparticles grown on SrTiO3 (STO) {001} and {110} surfaces at room temperature have been studied in ultrahigh vacuum by means of transmission electron microscopy and scanning tunnelling microscopy. It was shown that some Fe nanoparticles grow epitaxially. They exhibit a modified Wulff shape: nanoparticles on STO {001} surfaces have truncated pyramid shapes while those on STO {110} surfaces have hexagonal shapes. From profile-view TEM images, approximate values of the adhesion energy of the nanoparticles for both shapes are obtained.

[The investigation of understanding and comfort of patients taking Divigel(®) 1 mg].

Hormone replacement therapy (HRT) given by injection or administered orally or topically can improve the QOL of patients with menopausal symptoms. Because patient comfort is influenced largely by the dosage form, pharmacists should understand the properties of each dosage form and provide appropriate information to individual patients. In this study, we investigated the understanding of medicines and diseases of patients receiving HRT and discuss the approaches pharmacists can take to improve patients' adherence. Thirty-seven patients (mean age 51.7±3.6 years) taking estradiol gel (Divigel(®) 1 mg) completed a questionnaire asked by their pharmacist. Responses indicated 70% of patients failed to use the gel as prescribed, and they had poor knowledge of both the sites where the gel shouldn't be applied and appropriate measures to take if having forgotten to apply the gel (43% and 11% correct understanding, respectively). Since the duration of HRT treatment for menopausal symptom is 2-5 years, patients should be administered the minimum effective dose in the shortest amount of time. Hence it is important to maintain patients' adherence particularly in this limited administration period. HRT guidelines define HRT outcome as not only improvement of menopausal symptoms but also suppression of bone resorption, improvement of glucose and lipid metabolism, and reduced prevalence of Alzheimer's disease. Accordingly, pharmacists should facilitate proper adherence to HRT to improve and maintain women's QOL in the perimenopausal period, necessitating they actively provide pharmaceutical care such as preparing useful instructions patients can repeatedly use and periodically checking patients' understanding of their HRT medications.

X-ray analysis and mapping by wavelength dispersive X-ray spectroscopy in an electron microscope.

A compact and easy-to-use wavelength dispersive X-ray spectrometer using a multi-capillary X-ray lens attached to a scanning (transmission) electron microscope has been tested for thin-film analysis. B-K spectra from thin-film boron compounds (B4C, h-BN, and B2O3) samples showed prominent peak shifts and detailed structural differences. Mapping images of a thin W/Si double-layer sample resolved each element clearly. Additionally, a thin SiO2 film grown on a Si substrate was imaged with O-K X-rays. Energy and spatial resolution of the system is also discussed.

Development and application of an internet electron microscopy system for the outreach program in Japan.

The development of a remotely operated scanning electron microscopy (SEM) system and its use by high school students and the public as an outreach program are reported. The SEM and the server are located in the National Institute for Materials Science, Tsukuba, Japan, with client computers installed at a science museum and high schools. Using a secure virtual private network system and scheduling/management groupware, observation of SEM images and energy dispersive X-ray analysis are widely and frequently performed throughout Japan.

Second-harmonic spectroscopy of surface immobilized gold nanospheres above a gold surface supported by self-assembled monolayers.

We have investigated linear and nonlinear optical properties of surface immobilized gold nanospheres (SIGNs) above a gold surface with a gap distance of a few nanometers. The nanogap was supported by amine or merocyanine terminated self-assembled monolayers (SAMs) of alkanethiolates. A large second-harmonic generation (SHG) was observed from the SIGN systems at localized surface plasmon resonance condition. The maximum enhancement factor of SHG intensity was found to be 3 x 10(5) for the SIGN system of nanospheres 100 nm in diameter with a gap distance of 0.8 nm. The corresponding susceptibility was estimated to be chi((2))=750 pmV (1.8 x 10(-6) esu). In the SIGN system supported with the merocyanine terminated SAMs, the SHG response was also resonant to the merocyanine in the nanogap. It was found that the SHG response of the SIGN systems is strongly frequency dependent. This leads us to conclude that the large chi((2)) is caused by enhanced electric fields at the localized surface plasmon resonance condition and is not due to an increase of the surface susceptibility following from the presence of the gold nanospheres. The observed SHG was consistent with the theoretical calculations involving Fresnel correction factors, based on the quasistatic approximation.

TEM sample preparation using a new nanofabrication technique combining electron-beam-induced deposition and low-energy ion milling.

A new TEM sample preparation technique using electron-beam-induced deposition combined with low-energy ion milling was used to fabricate for two different shapes of sample, conical and plate. High-quality HREM images can be obtained from samples prepared by this technique. A desired sample position can be obtained with high accuracy, and the total sample preparation time can be much less than conventional techniques. Because the gas deposition system used can easily be integrated in a conventional SEM, the method can be performed in any laboratory equipped with a SEM and an ion milling machine.

Direct UHV-TEM observation of palladium clusters on a silicon surface.

About 1 monolayer of palladium was deposited onto a silicon (111) 7 x 7 surface at a temperature of about 550 K inside an ultrahigh vacuum transmission electron microscope, resulting in formation of Pd2Si nanoislands and a 1 x 1 surface layer. Pd clusters created from an excess of Pd atoms on the 1 x 1 surface layer were directly observed by in situ plan view high-resolution transmission electron microscopy. When an objective aperture was introduced so that electron diffractions less than 0.20 nm were filtered out, the lattice structure of the 1 x 1 surface with 0.33 nm spacing and the Pd clusters with a trimer shape were visualized. It was found that image contrast of the 1 x 1 lattice on the specific height terraces disappeared, and thereby an atomic structure of the Pd clusters was clearly observed. The appearance and disappearance of the 1 x 1 lattice was explained by the effect of the kinematical diffraction. It was identified that a Pd cluster was composed of three Pd atoms without a centered Si atom, which is consistent with the model proposed previously. The feature of the Pd clusters stuck at the surface step was also described.

Behavior of metal nanoparticles in the electron beam.

Fabrication and structural observation of In, Pd and Mo nanoparticles deposited on Si(110) substrates were performed in an ultrahigh vacuum field emission transmission electron microscope. In situ and/or dynamic observation of In nanoparticles showed fluctuation of their structures. The smaller particles of size of 3-5 nm showed frequent fluctuation, while the nanoparticles of more than 10 nm in size showed relatively slower fluctuation. The bigger nanoparticles showed coalescence with a weaker beam. Pd nanoparticles of size of 3-5 nm showed structural fluctuation after 10-30 s of electron beam irradiation. Stronger beam irradiation resulted in the dissipation of the nanoparticles probably due to diffusion. Mo nanoparticles of size of 3-5 nm never showed structural fluctuation. Intensive electron beam irradiation resulted in the dissipation of the particles. The difference in structural fluctuation depending on the metal and the beam intensity, and the peculiar coalescence of In nanoparticles are discussed qualitatively.