Nanolithography : status and challenges

With the help of immersion lithography and multiple patterning, photolithography has been the key technology over the last decade in manufacturing of ICs, microchips and MEMS devices. Continuous rapid shrinking of feature size made the authorities to seek alternative patterning methods that can go beyond classic photographic limits. Some promising techniques have been proposed as next generation lithography and further technological progress are required to make them significant and reliable to meet the current demand. EUVL is considered as the main candidate for sub-10 nm manufacturing because of its process simplicity and reduced operating cost. Remarkable progress in EUVL has been made and the tools will be available for commercial operation soon. EBL, FIB and X-ray lithography are used for patterning in R&D, mask/mold fabrication and low volume chip design. DSA have already been realized in lab and further effort will be needed to make it as NGL solution. NIL has emerged attractively due to its simple process-steps, high-throughput, high-resolution and low cost and become one of the commercial platforms for nanofabrication

Fe(ii) and Fe(iii) dithiocarbamate complexes as single source precursors to nanoscale iron sulfides: a combined synthetic and in situ XAS approach

Nanoparticulate iron sulfides have many potential applications and are also proposed to be prebiotic catalysts for the reduction of CO2 to biologically important molecules, thus the development of reliable routes to specific phases with controlled sizes and morphologies is important. Here we focus on the use of iron dithiocarbamate complexes as single source precursors (SSPs) to generate greigite and pyrrhotite nanoparticles. Since these minerals contain both iron(III) and iron(II) centres, SSPs in both oxidation states, [Fe(S2CNR2)3] and cis-[Fe(CO)2(S2CNR2)2] respectively, have been utilised. Use of this Fe(II) precursor is novel and it readily loses both carbonyls in a single step (as shown by TGA measurements) providing an in situ source of the extremely air-sensitive Fe(II) dithiocarbamate complexes [Fe(S2CNR2)2]. Decomposition of [Fe(S2CNR2)3] alone in oleylamine affords primarily pyrrhotite, although by careful control of reaction conditions (ca. 230 °C, 40–50 nM SSP) a window exists in which pure greigite nanoparticles can be isolated. With cis-[Fe(CO)2(S2CNR2)2] we were unable to produce pure greigite, with pyrrhotite formation dominating, a similar situation being found with mixtures of Fe(II) and Fe(III) precursors. In situ X-ray absorption spectroscopy (XAS) studies showed that heating [Fe(S2CNiBu2)3] in oleylamine resulted in amine coordination and, at ca. 60 °C, reduction of Fe(III) to Fe(II) with (proposed) elimination of thiuram disulfide (S2CNR2)2. We thus carried out a series of decomposition studies with added thiuram disulfide (R = iBu) and found that addition of 1–2 equivalents led to the formation of pure greigite nanoparticles between 230 and 280 °C with low SSP concentrations. Average particle size does not vary significantly with increasing concentration, thus providing a convenient route to ca. 40 nm greigite nanoparticles. In situ XAS studies have been carried out and allow a decomposition pathway for [Fe(S2CNiBu2)3] in oleylamine to be established; reduction of Fe(III) to Fe(II) reduction triggers substitution of the secondary amide backbone by oleylamine (RNH2) resulting in the in situ formation of a primary dithiocarbamate derivative [Fe(RNH2)2(S2CNHR)2]. This in turn extrudes RNCS to afford molecular precursors of the observed FeS nanomaterials. The precise role of thiuram disulfide in the decomposition process is unknown, but it likely plays a part in controlling the Fe(III)–Fe(II) equilibrium and may also act as a source of sulfur allowing control over the Fe : S ratio in the mineral products

Magnetic Particle-Based Hybrid Platforms for Bioanalytical Sensors

Biomagnetic nano and microparticles platforms have attracted considerable interest in the field of biological sensors due to their interesting physico-chemical properties, high specific surface area, good mechanical stability and opportunities for generating magneto-switchable devices. This review discusses recent advances in the development and characterization of active biomagnetic nanoassemblies, their interaction with biological molecules and their use in bioanalytical sensors

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

ハイパフォーマンスコーチングにおける栄養サポートの在り方 : 競技力向上と人間力育成の観点から

202

Aberrant Expression of HOX Genes in Oral Dysplasia and Squamous Cell Carcinoma Tissues

Human HOX genes consist of 39 genes and encode transcription factors that function as master developmental regulators. We hypothesized that the misexpression of HOX genes was associated with carcinogenesis and malignant progression. The expression levels of 39 HOX genes in 31 human oral squamous cell carcinoma (SCC), 11 dysplasia, and 10 normal mucosa tissues were quantified by the real-time RT-PCR method. The expression levels of 18 HOX genes in the SCC tissues were significantly higher than those in the normal mucosa tissues. The dysplasia tissues showed higher expression of HOXA2, A3, B3, and D10 than normal mucosa tissues whereas they showed lower expression of HOXA1, B7, B9, and C8 than SCC. The SCC with lymph node metastasis showed high expression of HOXC6 compared to the SCC without it. These results suggest that misexpressions of particular HOX genes are implicated in the development of oral dysplasia and SCC